Many things we have learned contradicts much of what we previously thought about the mind.  For example, it is quite common and sensible to believe that we come into the world with minds that are essentially “blank slates,” and that what we know is written on those slates by experience alone.  But that view appears to be wrong.

The human mind consists of a variety of distinct and interacting mental tools, each of which comes pre-loaded with some quite specific content and some processing algorithms.  For example, it is now clearly demonstrated that human beings are naturally endowed with what we might reasonably describe as innate beliefs and innate cognitive processors.

On the belief side, developmental psychologists have identified numerous domains of understanding that are native to us, such as folk physics, folk biology, folk psychology, agency detection tendencies, and so on. What these discoveries seem to show is that our minds are pre-disposed to come to think about the world in very specific ways—ways that are determined by the kinds of minds we have.

So it looks like from birth, or rather through a regular and maturationally natural process, we have dispositions for form beliefs in the following domains.

“Folks Physics”:

• Objects move on inertial paths
• Objects cannot move through other objects
• Objects must move through space
• Objects must be supported

“Folk Psychology”:

• Agents act to satisfy desires
• Agents have beliefs

“Folk Biology”:

• Animals bear young similar to themselves
• Living things need nutrients

In addition to these innate dispositions toward certain kinds of beliefs, we also seem to have cognitive mechanisms that dispose us to crunch sensory inputs in specific ways. We might call these “innate cognitive processors.” Examples of these would include things like contagion avoidance and agency detection.

Contagion avoidance is a natural aversion human beings share to things like dead bodies, animal waste and vomit, rotting food, etc. These things “gross us out” from a very early age.  Indeed, the aversions we have towards them pre-date any data we might come to possess that would lead us to judge them dangerous.  We are also repelled by them in ways that are independent of other aversive stimuli like smell (that is, you can’t explain this aversion by noting that people are scared off because of an unpleasant odor since studies show that the aversions are independent of that).

A second processor is our Agency Detection Device. Here, psychologists have identified a cognitive processor that seems to pre-dispose us to form beliefs in the reality and presence of (sometimes invisible!) agents under certain conditions. In these cases, when we look for the cause of certain events, motions, sounds, or structures, we are disposed to think that it was caused by a someone rather than by a something. Our ADD appears to be hypersensitive.  It is very good at detecting agency, and in fact is more likely to generate false positives than false negatives.  This is often referred to as our hypersensitive agency detection device (HADD), and may be reflected in manifold attributions of ghosts, fairies, forest spirits, and even personalities of machines!

In sum, psychologists have shown that our initial presumption about the contents of our mind was wrong. Our minds are not blank slates, but processing devices that come endowed with a complex operating system.

Many are quick to point out that this should not be surprising.  When we look across times and cultures and find very similar beliefs concerning the nature of physical, biological, and psychological reality, those similarities cry out for some explanation. Since these diverse individuals have a very wide range of experience, something other than, or in addition to, common experience would seem to account for the similarities of belief. And so it is natural to conclude that there is some fundamental similarity among human minds that explains it. And recent empirical evidence has in fact confirmed this conclusion.

One type of belief that is pervasive across times and cultures is religious belief.  One is thus led to wonder whether those sorts of beliefs are among those that we are naturally disposed to believe.  One New Zealand religion scholar, Joseph Bulbulia, argues that the emerging consensus is yes: “The view of mind expressed by Descartes as composed of innate understandings given in advance of any experience has been thoroughly vindicated after sixty years of cognitive psychology. It may be that Descartes will be shown correct on another score, namely that knowledge of the Divinity is imprinted on every mind [as well]”

Bulbulia’s remark invites us to entertain three key questions:

• Is there any evidence that we are naturally disposed to religion?
• How do we explain the origin of these dispositions?
• What are the implications of such explanations for belief itself?

These will be explored in the next post.

Like any theory, Darwin’s idea that evolution proceeds through natural selection was once merely a hypothesis. In this post, we’ll look at some of the early observations Darwin made on biogeography: the study of where species are distributed across the globe. These lines of evidence would later prod him to consider the possibility that species arise through a natural process of gradual change over time, rather than being independently created in each location where they are found.

The curious case of the missing mammals

As a widely-travelled naturalist on the HMS Beagle, Darwin studied a large number of different environments and documented the species he found in each. The Beagle, engaged as it was in an effort to map the coastline of South America, naturally paid call to numerous island groups along the way, including islands at a great distance from a continent (i.e.oceanic islands). One observation that Darwin made about oceanic islands is that none that he studied had terrestrial mammals on them. Later work, after his voyage, would confirm that this was a general rule. Oceanic islands lack terrestrial mammal species, except for small species that were introduced by humans. In contrast, flying mammals (i.e. bats) were found on oceanic islands, and often these species were endemic (i.e. found nowhere else in the world but the island in question).

Darwin found these observations difficult to square with his (then) working assumption that species were independently created in (and specifically created for) the locations in which they are found across the globe. He discusses these observations, and the questions they raised in his mind, in two chapters entitled “Geographical Distribution” in his Origin of Species. After discussing the similar case that amphibians (such as frogs, newts, and so on) are also not to be found on oceanic islands, he turns his attention to the missing mammals:

Mammals offer another and similar case. I have carefully searched the oldest voyages, but have not finished my search; as yet I have not found a single instance, free from doubt, of a terrestrial mammal (excluding domesticated animals kept by the natives) inhabiting an island situated above 300 miles from a continent or great continental island.... It cannot be said, on the ordinary view of creation, that there has not been time for the creation of mammals; many volcanic islands are sufficiently ancient, as shown by the stupendous degradation which they have suffered and by their tertiary strata: there has also been time for the production of endemic species belonging to other classes; and on continents it is thought that mammals appear and disappear at a quicker rate than other and lower animals. Though terrestrial mammals do not occur on oceanic islands, aërial mammals do occur on almost every island. New Zealand possesses two bats found nowhere else in the world: Norfolk Island, the Viti Archipelago, the Bonin Islands, the Caroline and Marianne Archipelagoes, and Mauritius, all possess their peculiar bats. Why, it may be asked, has the supposed creative force produced bats and no other mammals on remote islands? On my view this question can easily be answered; for no terrestrial mammal can be transported across a wide space of sea, but bats can fly across. Bats have been seen wandering by day far over the Atlantic Ocean; and two North American species either regularly or occasionally visit Bermuda, at the distance of 600 miles from the mainland. I hear from Mr. Tomes, who has specially studied this family, that many of the same species have enormous ranges, and are found on continents and on far distant islands. Hence we have only to suppose that such wandering species have been modified through natural selection in their new homes in relation to their new position, and we can understand the presence of endemic bats on islands, with the absence of all terrestrial mammals.

(As an aside, it’s important to note that Darwin, when he discusses the “supposed creative force” is not here arguing against the existence of God as creator in general, but rather against the “ordinary view of creation” common at the time: that God had episodically created species at specific geographical locations (what were called “centers of creation”) and that biogeographical patterns could be explained with limited dispersal from those centers. Darwin himself held to this common view at the start of his voyage on the Beagle, and that is the model he is attempting to refute in Origin, since it was a prevailing view among scientists at the time. Darwin and many of his scientific contemporaries also had no difficulty viewing natural processes as part of God’s regular action in the world, as is evident in Darwin’s correspondence with American botanist Asa Gray, among others.)

So, for Darwin, his biogeographical observations sat at ease with his (later) ideas of colonization and subsequent species change through natural selection, but made no sense to him if one held to an independent creation model. Many oceanic islands were very old, yet no mammals had been created there. Many oceanic islands had habitat suitable for mammals (or, indeed, for amphibians, as he notes) yet no such species had been created for that suitable habitat.

Island endemics and their continental “allied species”

Darwin noticed more than the absence of certain species groups on oceanic islands. He also noticed an interesting feature of the species that were present: an endemic species on an oceanic island would often have strong similarities with a species on the mainland closest to the island in question. Additionally, the pairing of oceanic endemic species with continental species often seemed to override expectations that species found in similar environments would be more similar to each other. These observations prompted him to reflect further on the possible means by which these “closely allied species” arose. As Darwin would write in his Origin this repeated pattern made a significant impression on him, and further caused him to doubt that endemic species had been individually created for each oceanic island. His visit to the Galapagos would prove instrumental on this point:

The most striking and important fact for us in regard to the inhabitants of islands, is their affinity to those of the nearest mainland, without being actually the same species. Numerous instances could be given of this fact. I will give only one, that of the Galapagos Archipelago, situated under the equator, between 500 and 600 miles from the shores of South America. Here almost every product of the land and water bears the unmistakeable stamp of the American continent. There are twenty-six land birds, and twenty-five of these are ranked by Mr. Gould as distinct species, supposed to have been created here; yet the close affinity of most of these birds to American species in every character, in their habits, gestures, and tones of voice, was manifest. So it is with the other animals, and with nearly all the plants, as shown by Dr. Hooker in his admirable memoir on the Flora of this archipelago. The naturalist, looking at the inhabitants of these volcanic islands in the Pacific, distant several hundred miles from the continent, yet feels that he is standing on American land. Why should this be so? why should the species which are supposed to have been created in the Galapagos Archipelago, and nowhere else, bear so plain a stamp of affinity to those created in America? There is nothing in the conditions of life, in the geological nature of the islands, in their height or climate, or in the proportions in which the several classes are associated together, which resembles closely the conditions of the South American coast: in fact there is a considerable dissimilarity in all these respects. On the other hand, there is a considerable degree of resemblance in the volcanic nature of the soil, in climate, height, and size of the islands, between the Galapagos and Cape de Verde Archipelagos: but what an entire and absolute difference in their inhabitants! The inhabitants of the Cape de Verde Islands are related to those of Africa, like those of the Galapagos to America. I believe this grand fact can receive no sort of explanation on the ordinary view of independent creation; whereas on the view here maintained, it is obvious that the Galapagos Islands would be likely to receive colonists, whether by occasional means of transport or by formerly continuous land, from America; and the Cape de Verde Islands from Africa; and that such colonists would be liable to modification;—the principle of inheritance still betraying their original birthplace.

Many analogous facts could be given: indeed it is an almost universal rule that the endemic productions of islands are related to those of the nearest continent, or of other near islands.

Rethinking independent creation

For Darwin, both of these observations (that oceanic islands lacked terrestrial mammals, and that endemic species on islands were most similar to a species on the closest mainland) had the same explanation: his hypothesis that endemic, oceanic species were the modified descendants of a colonizing species from the nearest continent. This also explained the lack of amphibians and terrestrial mammals (but allowed for bats) - simply based on the ability of these classes of life to disperse across large expanses of ocean. Those that could disperse and colonize oceanic islands would experience modification in the new environment, and species unable to colonize these islands would never appear. To Darwin’s thinking, this explanation was wholly more satisfactory than the assumption that God had independently created every endemic species in its place, and arbitrarily chosen that oceanic islands did not need terrestrial mammals and amphibians.

Despite Darwin’s musing on the biogeographical patterns he observed, and the strong suggestion these patterns made of species change over time, a mechanism for that change would take some time for him to imagine. In our next post, we’ll look at that mechanism: Darwin’s idea of natural selection, and the evidence he assembled in its support prior to publishing the Origin.

Grantees will benefit from in-person interaction through a series of summer workshops in 2013, 2014, and 2015. These meetings will not only foster a broader knowledge base, but will build a sustained network of scholars and church leaders, both young and seasoned, who are serious about addressing the concerns of the church about evolution. Also in 2015, in connection with the third summer workshop, BioLogos will host a large conference open to scientists, scholars, and church leaders from around the world.

ECF History

In January 2012, BioLogos was awarded a multi-million dollar grant from the John Templeton Foundation to fund the work of scholars and church leaders on evolution and Christian faith. In spring 2012 we worked hard to get the word out. You may have seen announcements on the BioLogos website, in our newsletters, on the Books & Culture, Leadership Journal, or First Things websites, on your professional society’s listserv, or perhaps on your friend’s blog.

The response was overwhelming: we received 225 letters of intent for a total request of $21 million—about seven times the amount we had to offer. We needed to invite the most promising applicants to submit a full proposal, but recognizing the projects with highest potential would require broad expertise. From the beginning, we envisioned that a panel of scientists, pastors, and scholars would oversee the application and review process as well as play key advisory roles throughout the project. A team of eight highly qualified individuals came on board in the early months of the project. They reviewed each proposal and together recommended that BioLogos invite 86 applicants to submit full applications.

The deadline for submissions was October 1, 2012. As in the previous round, the ECF panel evaluated each proposal. In addition, we asked 55 other experts to participate, so that each proposal received 3-4 scores. Criteria for the decision included significance of topic, project design, creativity and innovation, long-term impact potential, feasibility, and budget.

The panel then met together November 29-30, 2012, to make the final funding decisions. In the end, they recommended that BioLogos give 37 awards, ranging from $23,000 to $300,000. BioLogos staff notified applicants of their awards on December 14, 2013.

The Grantees

As part of our objective to create a network of scholars and leaders, we awarded grants to organizations across the U.S. and the world. Thirty of the 37 grantees are domestic; seven are international, hailing from Canada, France, Great Britain, Netherlands, and Spain.

Two-thirds of the accepted projects will be led by teams—some with three or more Project Leaders. We expect that the teamwork and time spent together at our summer workshops will be the start of a long-lasting network of people dedicated to helping the church think carefully about origins.

Applicants chose to apply under one of three program tracks: interdisciplinary scholarship (Track 1), intra-disciplinary scholarship (Track 2), and translational projects (Track 3). Track 1 projects focus on both the collaboration between individuals in different disciplines and the development of projects at the interface of different content areas. Track 2 projects focus on work done within a specific discipline. Track 3 focuses on projects that encourage Christians, especially those within more conservative traditions, to engage in meaningful and productive dialogue to reduce tensions between mainstream science and the Christian faith. The numbers of grantees in Tracks 1, 2, and 3 are 6, 8, and 23, respectively.

Many of the scholarly projects tackle questions about Adam and Eve, the Fall, human identity, and Original Sin—some of the most critical interpretive issues for evangelical theology.  Some examples: 

• Theologian Oliver Crisp of Fuller Seminary will take an analytic theology approach to ask to what extent a theological account of the origin of human sin depends upon the evolution of modern humans from one and only one ancestral pair—especially if that pair does not appear to correspond to what we would think of as modern human beings. 

• Pastor Michael Gulker and philosopher James Smith, leading a large team from The Colossian Forum, ask a related question: if humanity emerged from non-human primates—as genetic, biological, and archaeological evidence seems to suggest—then what are the implications for Christian theology’s traditional account of origins, including both the origin of humanity and the origin of sin? 

• Biologist Dennis Venema of Trinity Western University and New Testament scholar Scot McKnight of Northern Seminary will write a book on the evidence for evolution and population genetics, with informed theological reflection on how these issues interact with orthodox Christianity.

• Biologist David Wilcox of Eastern University will develop an updated model of human identity which reflects the complex recent scientific advances in genetics and paleoanthropology and yet is sensitive to theological concerns.  

These are just a few of the scholarly awards; check out the Grantees page for full descriptions of all Track 1 and Track 2 projects.

All projects have translational potential, but Track 3 projects are designed to meet the needs of a particular constituency within the evangelical church. These projects run the gamut from ethics to education to media production to ministry resources.  Some examples include:

• Theologian Lee Camp of Lipscomb University will produce “The Questions in Monkey Town,” an episode of Tokens, a live variety show that features musical performances, comedic sketches, brief interpretive monologues, and dialog with authors and scholars. The episode will be performed and filmed on the site of the famous Scopes Trial in Dayton, Tennessee.

• Chaplain Joshua Hayashi and Educator Diane Sweeney of the Punahou School in Hawaii will lead a team to produce multimedia curricula aimed at helping high school students connect with their biology curricula and, at the same time, deepen their Christian faith.

• Physics teacher and pastor Benoît Hébert of Science et Foi Chrétienne in France will lead an international, multi-denominational team of French speaking Evangelical scientists, pastors and church leaders to produce a large number of resources on evolutionary creation.

• Pastor Seung-Hwan Kim of Grace Truth Community Church, a Southern Baptist church in Cambridge, Massachusetts, will produce teaching and preaching materials about evolution for church leaders.

• President Gregory Wolfe and Director of Resource Development for IMAGE will gather artists and writers of faith whose work explores the dialogue between evolutionary science and faith practice, convening a conversation between them and scientists, theologians, and church leaders in private and public conferences.

Again, this is just a taste of the diversity of Track 3 projects. Read more about each project on the Grantees page. You can look forward to an incredible variety of resources coming out of the ECF program, many of which will be featured right here on the BioLogos Forum.

A common argument leveled against the theory of evolution is that scientists have not been able to produce the expected transitional fossils that show the change of one species into another. If evolution were true, wouldn’t there be instances of clear intermediary species, like, for example, a species that was half whale and half hippo to show the transition between those two? In this BioLogos podcast, Kelsey Luoma addresses this misconception about what a transitional fossil actually is. Rather than a mix between two related species, transitional fossils point back to the common ancestors that modern species share. The fact is that the number of transitional species is massive and it grows with each passing year. Given the rarity with which organisms are actually fossilized, the amazing thing is actually the completeness of the fossil record, not its incompleteness. The transitional species story strongly supports, and certainly does not disprove, evolutionary theory. ¹

1. To hear the full audio clips which have been referenced go to:

• Rational Response Debate with Kirk Cameron (from Way of the Masters)
• Behind the Scenes with Dr. Neil Shubin (from Cincinnati Museum Center)
• Mark Norell Publishes New Archaeopteryx Findings (from American Museum of Natural Sciences)
• Texas A&M Professor Discusses Findings of Autralopithecus Sediba and its Relationship to Humans (from Texas A&M University)
• Intro/outro music composed by Martin Minor (Minor2Go).

An audio only version of the podcast can be downloaded here.

1. We are a world that longs for goodness and beauty, whether we are believers or not.

2. The data from emerging neuroscience and attachment research points us to a world of goodness and beauty.

3. This same data reflects and energizes the biblical narrative. Creation itself points us to the very story God is telling.

4. One of the most integral processes—that helps us get to truth and beauty—involves the changing (and renewal) of our minds. The renewal of our minds is a subset of the renewal of everything. God is on a mission of complete renewal, albeit on his timetable.

In this mission for renewal, one of the most important aspects is the interpersonal experience of being known. We change primarily not by what we know, but by how we are known. We live in a culture that is really good at knowing things, but not so good at being known.

5. Our first reaction is likely to be, “How will knowing this stuff change me?” But the biblical narrative is not just about us as individuals, it is about a world of mercy and justice. In order for us to have mercy and justice, we don’t do it primarily as individuals, we do it as institutions. God’s renewal is not just about changing us, it is about changing everything.

See part 2 for the second half of Dr. Thompson's presentation

With the complete genome sequence in hand, we knew the sequence and location of our genes, but what we didn’t know was how all those genes are regulated: how do the trillions of cells in our bodies know when to turn on or off all those genes? How do the hundreds of distinct cell types develop and function together, when they are all running on the same DNA “operating system?”

That’s where the ENCODE (short for Encyclopedia of DNA Elements) project comes in. Launched in September 2003, shortly after the announced completion of the Human Genome Project, the goal of the ENCODE project is “to build a comprehensive parts list of functional elements in the human genome, including elements that act at the protein and RNA levels, and regulatory elements that control cells and circumstances in which a gene is active.” In other words, the project seeks to understand how the genome “works.”

Early this month, researchers from ENCODE released more than thirty papers presenting their findings. During a Science magazine online chat, the project’s data coordinator, Ewan Birney, explained the outcome:

The ENCODE project aimed to start our understanding of how the human genome works. We know that (nearly) all the information that determines a human is in the genome, as we all start off as single cell with this DNA. However, we had a patchy understanding of how it works, in particular away from protein coding genes.

To work out how the genome works, we used the fact there are many tiny machines (proteins and RNA - RNA is very like DNA) in each of our cells which know how to "read" parts of the genome. By monitoring where these little molecular machines are on the genome, or how parts of the DNA are copied into RNA (there are quite a few different types of RNA as well), we start to gain some insight into the genome.

We did many such experiments, across different cell types (eg, one cell type was very similar to a liver cell type; another was very similar to a white blood cell). This way not only can we see what is similar, we can also see differences between these cell types.

There is a lot more to get to know and understand here - this is definitely closer to the start than the end. But it is a substantial amount of data, and analysis, to start on this journey.

According to the abstract of one of the lead papers from Nature, this extraordinary glut of data “enabled us to assign biochemical functions for 80% of the genome, in particular outside of the well-studied protein-coding regions.” Only 2% of the genome codes for proteins, but 80% or more has some biochemical function. As a Science news article put it, these 30 papers “sound the death knell for the idea that our DNA is mostly littered with useless bases.”

The pro-Intelligent Design organization The Discovery Institute has heralded the discovery as the “demise of junk DNA.” Casey Luskin writes for their blog Evolution News:

Let's simply observe that it provides a stunning vindication of the prediction of intelligent design that the genome will turn out to have mass functionality for so-called "junk" DNA. ENCODE researchers use words like "surprising" or "unprecedented." They talk about of how "human DNA is a lot more active than we expected." But under an intelligent design paradigm, none of this is surprising. In fact, it is exactly what ID predicted.

The extent to which the ENCODE project been able to identify function has been surprising—even exhilarating—though scientists have for some time been getting glimpses of the many ways in which segments of DNA can be “active.” Even in 1970 biologists knew that some non-coding DNA had function, and by 2003 there was a large body of work demonstrating that many non-coding elements acted as promoters, enhancers, insulators, and so on. Indeed, in recent years many have come to appreciate the fact that “junk” was never really an appropriate metaphor in the first place. Still, because sequencing of multiple genomes has shed such extraordinary light on key evolutionary mechanisms, many geneticists have focused on function primarily in terms of which regions do or do not contribute to the evolutionary fitness of their host, rather than whether they were merely "doing something" biochemically. What the impressive ENCODE project has done is open a treasure trove of new information that can only accelerate the pace at which researchers are able to explore the incredible subtlety and complexity of DNA, and refine the very concept of “functionality.”

So with all this in mind, is ENCODE a stunning victory for ID, as Luskin believes? Bryan College biologist Todd Wood thinks not. He writes, “I don't think that function equates to design, nor do I think that design requires or predicts function. They're not the same thing… my understanding of function does not require me to hypothesize God (or an anonymous designer, if you must) as the proximal cause.”

We agree. Indeed we would go on to say that evolution and design are not mutually exclusive. So while finding function is not sufficient to prove design, recognizing that function has arisen by way of evolution does not indicate that God was not at work. We at BioLogos believe God providentially works out his purposes—his designs—through the elegant processes of evolution, not in opposition to them.

Amazing as the new data are, it only strengthens and enhances our evidence for evolution. While much of the genome is “doing something” biochemically, it is still likely that the majority of the sequence is evolutionarily neutral (Senior Fellow Dennis Venema discusses the evidence for this “neutrality” in a post on our site, including a striking comparison between 29 different mammal genomes and the human genome). In fact, another ENCODE researcher participating in the Science magazine chat, John A. Stamatoyannopoulos of the University of Washington School of Medicine, thinks the findings align beautifully with evolutionary theory:

ENCODE's data provide a unique and powerful window through which to view evolutionary change. We can see those changes directly by lining up the genome sequences of many different organisms -- these line-ups have revealed millions of regions where all the genomes agree, indicating sequences that have been specially preserved by evolution while others have decayed away (ie freely changed their letter codes). We now see that a large proportion of these 'conserved' regions are lighted up by ENCODE annotations, indicating that they are marking spots in the genome that contain important instructions for cell function.

We’ve discussed “junk” DNA previously, including a multi-part series by Dennis Venema, and we’ve received many emails over the past few days asking for our comments on the ENCODE findings. On Monday and Tuesday, Dr. Venema will begin to offer his own thoughts on ENCODE.

A special thanks goes to Darrel Falk, Mark Sprinkle, Kathryn Applegate, Dennis Venema, and Tom Burnett for their contributions to this post.

The Denisovans, an extinct hominid group that interbred with modern humans, made the news again lately with the publication of a more detailed study of their genome. One of the many interesting findings was that the Denisovans share the same chromosome 2 fusion that modern humans have. In this post, I review what we know about the origins of human chromosome 2, and then discuss the new Denisovan findings and their implications.

The origins of human chromosome 2: a brief review

Though I have discussed the evidence for a fusion event leading to human chromosome 2 before, perhaps a brief review of the evidence is in order. The human genome is made up of 23 pairs of chromosomes (for a total of 46 chromosomes). This makes us something of an oddity among living great apes, all the rest of whom have 24 pairs of chromosomes (for a total of 48). Given that there are many independent lines of evidence that support the conclusion that we share a common ancestor with other great apes, this poses something of a conundrum: how is it that our species arrived at this specific chromosome number? If we were to represent this “problem” on a phylogeny, or tree of relatedness, it would look something like this (not to scale):

Our closest living relatives, chimpanzees and bonobos, both have 48 chromosomes, as do all other great apes such as gorillas and orangutans. This pattern has one of two explanations, one of which is much more likely than the other. Either the common ancestor to these species had 48 chromosomes, and there was an event that reduced that number to 46 specifically on the lineage leading to humans (option A), or the common ancestor species had 46 chromosomes, and there were independent, repeated events that increased chromosome number in all other great ape species (option B). We can compare these options by placing the required event(s) on the phylogeny (again, not to scale):

It should be obvious that the option that requires the fewest events is the more likely one – in this case option A with an event that reduces chromosome number in the lineage leading to humans. The other option, that of repeated, independent events to increase chromosome number, remains a formal, but unlikely, possibility. Events that reduce chromosome number are not frequent occurrences, so Option A is more likely than Option B.

We can also find further support for Option A, because it predicts a specific type of event, namely one that reduces chromosome number. Since loss of a large amount of chromosomal material is almost always detrimental, we need an event that reduces chromosome number without losing information. One way for this to happen is for two chromosomes to fuse together and become one. Initially, this event would produce an individual with 47 chromosomes, where two different chromosomes get stuck together. Contrary to what is often assumed, this individual would be fertile and able to interbreed with the others in his or her population (who continue to have 48 chromosomes). In a small population, over time, two relatives who both have one copy of the fusion chromosome may mate and produce some progeny with two copies of the fused chromosome, or the first individuals with 46 chromosomes. Since either a 48-pair set or a 46-pair set is preferable for ease of cell division, this population will either eventually get rid of the fusion variant (the most likely outcome), or by chance will switch over completely to the “new” form, with everyone bearing 46 chromosome pairs. While not overly likely, this type of event is not especially rare in mammals, and we have observed this sort of thing happening within recorded human history in other species. Some mammalian species even maintain distinct populations in the wild with differing chromosome numbers due to fusions, and these populations retain the ability to interbreed.

Further evidence for a fusion event in the lineage leading to modern humans comes from comparing synteny, or gene locations and orders on chromosomes within modern great apes – an issue we have discussed here before. In brief, what we see in human chromosome 2 is exactly what we would predict for a fusion event. When compared to other great apes, we see the genes on human chromosome 2 match up, in order, with two smaller ape chromosomes. We also see that sequences used at the tips of chromosomes are present at the proposed fusion site, and that human chromosome 2 has not one but two sites for the cell cytoskeleton to attach to for cell division – but that one of the sites is mutated and not functional, though it lines up precisely with the location of this site on the appropriate ape chromosome. Together, this evidence consistently supports both common ancestry for humans and great apes, and specifically that the difference we see in our chromosome numbers arose due to a single fusion event. I briefly discussed this evidence in my last post where I describe how I teach some of this material and the compelling impact it has on students exploring the evolution question for the first time.

Enter the Denisovans

With that as background, we are now prepared to appreciate a new finding that comes from genomics work done on the Denisovan hominids, an archaic species that is more closely related to Neanderthals than to us, but that nonetheless interbred with some anatomically modern humans as they migrated out of Africa and populated the globe. (For those not familiar with the Denisovans, or the evidence for our interbreeding with them, both Darrel Falk and I have written on this previously, here and here). Recently, a more detailed understanding of the Denisovan genome was published, and nested in the new information is the discovery that the Denisovans share the 46 chromosome set with the same fusion that we have. This strongly supports the hypothesis that the fusion event predates the separation of our species. If we were to represent this on a phylogeny, we can now place this event with more accuracy than before (as before, the phylogeny is not to scale):

Despite this new information, one obvious question remains. Did the Neanderthals also have the 46-pair set? From looking at the phylogeny above, we can see that the most likely answer is that they did, since the fact that the Denisovans had it strongly implies that the last common ancestor of humans and Neanderthals / Denisovans had it as well, and the Neanderthal-Denisovan split comes later. While the Denisovan DNA samples are of high enough quality to make this assessment, we do not yet have Neanderthal DNA of high enough quality to do the same analysis with current methods (though one additional feature of the new work on the Denisovan genome is developing more sensitive DNA sequencing techniques that may resolve this question in the future).

In other words, this fusion seems to be an ancient one, predating our species by several hundred thousand years. Present estimates of the last common ancestor between humans and Neanderthals / Denisovans range at about 800,000 years ago.

Implications for understanding our “becoming human”

The main implication from this work is that it places the fusion event well before the advent of our species. I’ve often chatted informally with Christians about evolution, and at times some have thought that this fusion event was what “started” our species, or made our species unable to interbreed with other groups. Some have even suggested that perhaps the fusion event was what produced the first human (i.e. Adam).

Note that thinking this way suggests a misunderstanding of how chromosome fusions occur and what effect they have on their hosts. A fusion does not precipitate a speciation event, but rather the individual with the fusion remains a part of his or her population, and able to interbreed, even if with reduced fertility. Also, there is no necessary biological effect or change that the fusion produces on the appearance of the organism. These misunderstandings aside, however,what this new evidence shows is that this fusion event took place long before modern humans arose at around 200,000 years ago. Indeed, the 800,000 years ago date for the last human - Denisovan common ancestor means that this is the most recent date possible for the fusion. While it is an interesting piece of our evolutionary history, it doesn’t seem to have much to do with how we came to acquire the traits that set us apart from, and ultimately outcompete, other similar species.

Let me be clear. I do not reject dualism on account of any kind of philosophical or other kind of argument. In fact, I find many arguments against dualism—philosophical and otherwise—to be pretty weak specimens. I’m what a friend calls an antecedent materialist. In other words, I come to the discussion assuming I am a physical object, since that is what I have always seemed to myself to be for as long as I can remember. A non-physical soul doesn’t explain anything about consciousness that cannot be explained without it, and it is furthermore a wholly unnecessary hypothesis for many religious doctrines, despite intuitions to the contrary by many religious believers. For example, belief in an afterlife, belief in the peculiarly Christian idea of the incarnation of Christ, as well as the belief that we human beings bear the image of God—none requires belief in a non-physical soul in order to be made sense of. So until I am confronted with some knock-down, drag-out argument to the contrary, or until I am presented with some phenomena that cannot be accounted for in naturalistic terms or, yet again, until I have something resembling a conversion experience that forces me to renounce my physicalism, I'm sticking with it.

To go a bit further, let’s consider several theological doctrines that seem to cut against a physicalist conception of human personhood. These constitute perhaps the three most common objections Christian physicalists receive to their physicalism. After I address these objections, I will say a little more about the content of my own physicalist conception of human persons, The Constitution View. Perhaps in a future post I can say a little bit about the science of consciousness itself and address some of the most common objections to physicalism based on that mysterious phenomenon.

Theological Objections to Physicalism about Humans

The Incarnation of Christ

The doctrine of the incarnation of Christ is a central tenet of Christianity, and it may seem that the doctrine is inconsistent with a physicalist conception of human personhood. Yet I believe a physicalist view of human persons—like my own—actually makes better sense of the incarnation than does dualism. Let me explain.

The putative problem for the physicalist is this: if God (or the second person of the Trinity in particular) is essentially a non-physical being, then how could such a being become purely physical without losing an essential property? And if the second person of the Trinity loses an essential property, then wouldn’t he not simply cease to be fully God but simply cease to exist? (An essential property is a property a thing has and can’t lack without ceasing to exist. For example, my dog has the property of being a canine. He can’t lose that property without ceasing to exist—he is essentially a canine.)

Well, according to the Chalcedonian formulation, the incarnate Christ is one Person with two natures, a fully divine nature (that of the Second Person of the Trinity) and a fully human nature (that of Jesus from Nazareth). The Constitution View I hold divides things just where one would expect—between the human nature and the divine nature of the single person. And keep in mind, by the way, that the person of Christ is not human; he is divine, being the second person of the Trinity. But this one person, in the incarnation, had two natures--human and divine. In this understanding of the dual natures, Christ is wholly non-physical in his divine nature and wholly physical in his human nature. Now consider the somewhat-awkward cleavage Substance Dualists must offer. According to Substance Dualism, Christ is wholly non-physical in his divine nature and partly physical and partly non-physical in his human nature. Not especially elegant. To my mind, far from being unable to accommodate the doctrine of the incarnation, my physicalist view of human persons is actually better able to explain the doctrine than is dualism.

Notice that if what I said above is true, the way this objection is often put contains an important mistake in assuming that the second person of the Trinity ceased to be something he was apart from the incarnation. Indeed, the second person of the Trinity did not become purely physical (or even partly physical!). The second person of the Trinity did not give up non-physicality in the incarnation. Remember: one person (Divine and non-physical) with not one but (in the incarnation) two natures—one non-physical, the other physical. How can that be? I don’t have the slightest idea; but, the mystery of the incarnation is not explained away by any account, be it dualist or physicalist.

The Imago Dei

Now, what of the imago Dei or image of God? If it’s true that we human persons are wholly physical beings—as any version of physicalism must claim—then what does it now mean to say that we have been created in God’s image? Doesn’t having been created in the image of God just mean having a non-physical soul and the features of intellect, will and emotion that characterize soul? I do not believe that our having been created in the image of God means that we are non-physical as God is non-physical. What then does it mean?

Well, there are many ways of understanding the claim that we human beings image God. One might mean that we image God when we care for Creation and contribute to the terrestrial flourishing of the Created order. This, after all, is what the Bible means when it speaks of our having been given “dominion”. We are God’s vice-regents, as it were. To have dominion is to care for others, including non-human “others” like oceans and streams, octopus and salamander; in other words to have dominion is tend to the well being of all the earth. Second, one might mean that we image God when we live in loving relation to other human beings and invest ourselves in their flourishing and well being. For we are essentially persons-in-relation. Since God is a Trinity, it is not surprising that we should image God in virtue of our essentially social nature. The tenor of the relation between the three persons of the trinity is one of a harmonious and free exchange of love and joy. So engaging in acts of mercy, hospitality, love, kindness, etc. is to act like God. In fact, we image God when we image Jesus, who welcomed the outcast, fed the hungry, clothed the naked, hated evil and delighted in doing the work of the Father. Finally, one might claim that we image God in our suffering. God is love. To love is to open oneself up to suffering. And suffering love is God-love.

Now of course none of these ways that I have mentioned that we image God rules out the possibility that we are wholly or partly non-physical beings; but it doesn’t imply it either. The fact that we have been created in the image of God is perfectly compatible with the claim that we are wholly physical beings. Indeed, there is nothing in the doctrine of the imago Dei, rightly understood, that entails a dualist view of human nature.

But even if neither the doctrine of the incarnation nor the doctrine of humanity as reflecting the imago Dei require that we be at least partially non-physical beings, what about the issue of life after death? I’ll address that third challenge to a Christian physicalism tomorrow.

Yet it doesn’t follow that we are mere animals, and our rationality is what sets us apart from the rest of the genus. Indeed, for Aristotle, and for Aquinas after him, rationality is unlike our other capacities in having an essentially immaterial and non-bodily aspect. The reason has to do with our capacity to form abstract concepts, which underlies all our other distinctively rational activities. It is because you can grasp what it is to be a man -- not just this particular man or that one, but any possible man, man as a universal -- that you can go on to form judgments like the judgment that all men are mortal, can reason from that judgment together with the judgment that Socrates is a man to the conclusion that Socrates is mortal, and so forth.

There are several arguments that establish that this capacity for abstract thought cannot in principle be reduced to or otherwise entirely explained in terms of brain activity, even if brain activity is part of the story. The arguments have their roots in Plato and Aristotle and have been defended in recent years by Aristotelian philosophers like Mortimer Adler, John Haldane, David Oderberg, and James Ross.¹ Answering the various objections to (and misunderstandings of) these arguments takes some work, but the basic idea can be set out fairly simply.²

Let us take as an example the thought that triangles have three sides. For that thought (or any other) plausibly to be material, it would have to be identifiable with something like a symbol or set of symbols encoded in the brain -- something analogous to the symbols encoded in the electronic circuitry of a computer. But there is no way a thought could be entirely reducible to that sort of thing. For no material symbol could possibly have the determinate or unambiguous content that at least many of our concepts have; and no material symbol could possibly have the universal reference that our concepts have.

Consider the most unambiguous symbol of triangularity there could be -- a picture of a triangle, such as the one to the right. Now, does this picture represent triangles in general? Or only isosceles triangles? Or only small isosceles triangles drawn in black ink? Or does it really even represent triangles in the first place? Why not take it instead to represent a dinner bell, or an arrowhead? There is nothing in the picture itself that can possibly tell you. Nor would any other picture be any better. Any picture would be susceptible of various interpretations, and so too would anything you might add to the picture in order to explain what the original picture was supposed to represent. In particular, there is nothing in the picture in question or in any other picture that entails any determinate, unambiguous content. And even in the best case there is nothing that could make it a representation of triangles in general as opposed to a representation merely of small, black, isosceles triangles specifically. For the picture, like all pictures, has certain particularizing features -- a specific size and location, black lines as opposed to blue or green ones, an isosceles as opposed to scalene or equilateral shape -- that other things do not have.

Now what is true of this “best case” sort of symbol is even more true of linguistic symbols. There is nothing in the word “triangle” that determines that it refers to all triangles or to any triangles at all. Its meaning is entirely conventional; that that particular set of shapes (or the sounds we associate with them) have the significance they do is an accident of the history of the English language. But something similar could be said of any material symbols whatever. Even if we regarded them as somehow having a built-in meaning or content, they would not have the universality or determinate content of our concepts, any more than the physical marks making up the word “triangle” or a picture of a triangle do. But then the having of a concept cannot merely be a matter of having a certain material symbol encoded in the brain, even if that is part of what it involves. Nor can it merely be a matter of having a set of material symbols, or a set of material symbols together with certain causal relations to objects and events in the world beyond the brain. For just as with any picture or set of pictures, any set of material elements will be susceptible in principle of alternative interpretations; while at least in many case, our thoughts are not indeterminate in this way.

We might understand the point by analogy with sentences. If you are going to use the English sentence “Snow is white,” you are typically going to have to express it via some material medium -- ink marks, pixels, sound waves, or what have you. All the same, the meaning of that sentence cannot be accounted for in terms of any of the physical properties of those media. There is nothing in the shapes of the letters that make up the words of the sentence, or the chemistry of the ink in which they are written, or the physics of the compression waves in the air that you generate when uttering them, that makes them refer to snow or to whiteness or indeed to anything at all. A sentence is a seamless unity of the material and the immaterial, and it is created by another seamless unity of the material and immaterial -- a human being.

At this point there will no doubt be those who object that positing ectoplasm or spook stuff is hardly a better explanation of thought than an appeal to brain activity is. And that is quite true. But then, I said nothing about ectoplasm or spook stuff in the first place. When a mathematician points out that it is just muddleheaded to speak of the square root of 25 as if it were a kind of physical object, it would be silly to accuse him of believing that the square root of 25 is made out of ectoplasm or spook stuff. If your picture of reality cannot accommodate numbers alongside physical objects, that is your problem, not his. Mathematics simply provides a powerful example of a body of truths that cannot be captured in the language of physics, chemistry, neuroscience, and the like.

Similarly, to point out that whatever a thought is, it cannot in principle be reduced to the physical properties of brain activity, is simply to provide another example of an aspect of reality that cannot be entirely captured in such language. Only if we assume that all of reality must be so captured will this sound odd, but that we should not assume this is, of course, precisely the point. And if we do assume it, we are doing so in the face of the evidence, and not on the basis of the evidence. For it is precisely what we know about thought from our everyday familiarity with it -- such as the fact that it sometimes has a determinate content, and a universal reference -- that tells us that it cannot be entirely material, just as it is what we know about numbers from our everyday familiarity with them that tells us that they cannot be physical objects.

But doesn’t neuroscience show that there is a tight correlation between our thoughts and brain activity? It does indeed. So what? If you smudge the ink you’ve used to write out a sentence or muffle the sounds you make when you speak it, it may be difficult or impossible for the reader or listener to grasp its meaning. It does not follow that the meaning is reducible to the physical or chemical properties of the sentence. Similarly, the fact that brain damage will seriously impair a person’s capacity for thought does not entail that his thoughts are entirely explicable in terms of brain activity.

Aristotle and Aquinas, though they regarded the human intellect as immaterial, would not have been surprised in the least by the findings of modern neuroscience. Indeed, they would have been surprised had neuroscience not turned up the correlations it has. This will sound surprising if you take Descartes as your paradigm of a philosopher who affirms the immateriality of the human mind. But defending Descartes is exactly the reverse of what I have been doing. For it was Descartes who substituted the real, concrete human being -- a seamless unity of the physical and the mental, the bodily and the immaterial -- with a bizarre patchwork of abstractions of his own devising. Materialists have followed him ever since. Materialism is just a riff on Cartesianism, not its opposite. Tomorrow, I’ll explain exactly what I mean.

Notes

1. See Mortimer Adler, Intellect: Mind Over Matter (New York: Collier Books, 1990); J. J. C. Smart and J. J. Haldane, Atheism and Theism, Second edition (Oxford: Blackwell, 2003), pp. 96-109; David S. Oderberg, “Hylemorphic Dualism,” Social Philosophy and Policy 22 (2005); and James Ross, “Immaterial Aspects of Thought,” Journal of Philosophy 89 (1992).
2. I provide an exposition and defense of such arguments in chapter 7 of my book Philosophy of Mind and chapter 4 of my book Aquinas. An especially detailed exposition and defense can be found in my article “Kripke, Ross, and the Immaterial Aspects of Thought,” forthcoming in the American Catholic Philosophical Quarterly.

What Is at Stake?

What does it mean to be human? In what ways, if any, is our essential humanity tied to body and soul, mind and brain? This is not the stuff of mere curiosity. A host of pressing issues are at stake:

• Is there anything about humans that our mechanical creations, our innovations in Artificial Intelligence, will be unable to duplicate?
• What view of the human person helps us to find what we want to know about ourselves theologically — about sin, for example, as well as moral responsibility, repentance, and growth in grace?
• Am I free to do what I want? Given what we have learned about brain functioning, how might we understand the “free” in “free will”?
• What portrait of the human person is capable of casting a canopy of sacred worth over human beings, so that we have what is necessary for discourse concerning morality and for ethical practices?
• If humans, like sheep, can be cloned, will the resulting life form be a “person”?
• How should we understand “salvation”? Does salvation entail a denial of the world and embodied life, focusing instead on my “inner person” and on the life to come?
• How ought the church to be extending itself in mission? Mission to what? The spiritual or soulish needs of persons? Society-at-large? The cosmos?
• What happens when we die? What view(s) of the human person is consistent with Christian belief in life-after-death?

For many, and not least for many Christians, what makes a human genuinely human is the identification of the human person with his or her soul. From the second century on, theologians debated the origin of the soul: Are souls created by God ex nihilo at the moment of their infusion into the body? Are body and soul formed together? Are souls preexistent? Indeed, in the late-second century it was clear to many, as the Letter to Diognetus puts it, that “the soul dwells in the body, yet is not of the body” (1.27). Traditionally, systematic theology has discussed the uniqueness of humanity in two theological loci: human creation in the divine image and the human possession of a soul. Often these two are reduced to one, with the soul understood as the particular consequence of creation in God’s image.

For persons of faith — Christians included, but many others besides — the idea of a soul separable from the body is not only intuitive but necessary. We have regularly appealed to the soul as proof that humans are not mere animals, and so as a foundation for our views of the sacredness of human life. Moreover, Christians generally have derived from belief in the existence of the soul their affirmation of the human capacity to choose between good and ill. Further, the existence of a nonphysical soul, distinct and separable from the body, is typically regarded as the means by which human identity can cross over the bridge from this life to the next. Indeed, traditional Christian thought has tended to regard the body as frail and finite, the soul as immortal.

But it is the human possession of a “soul” that science now questions. When, as neurobiology and evolutionary psychology increasingly urge, the attributes and capacities traditionally allocated to the human soul are conditioned at point after point by biological processes, on what basis can belief in a soul be maintained? If science is generating “a radically new understanding of what it means to be human,”³ then those of us in the church must prepare ourselves for searching questions about the propriety of Scripture and traditional Christian thought in our talk about humanity, salvation, the end time, and more.

Before we engage too much in worried hand-wringing, however, we should ask whether our situation is so dire. Do these innovations in our understanding of personhood in fact call into question our deepest beliefs as Christians? Interdisciplinary study — with contributions from neuroscience, but also from biblical studies, theological studies, ethics, and philosophy (see “Further Reading,” below) — are demonstrating that emerging scientific portraits of the human person are neither as novel as we might imagine, nor as threatening to the essential tenets of Christian faith.

Biblical Contributions

In the context of current discussion on the nature of the human person, the Christian Scriptures have two primary contributions. First, taken as a whole, the biblical witness is fully congruent with a view of the person that affirms the human being as bio-psycho-spiritual unity. Neurobiological evidence and/or philosophical arguments favoring some form of monism are not at all hostile to the witness of Scripture. Second, we must recognize that the Old and New Testaments do not define the human person in essentialist but above all in relational terms. Put differently, the Bible’s witness to the nature of human life is at once naive and profound. It is naive not in the sense of gullibility or primitiveness, but because it has not worked out in what we may regard as a philosophically satisfying way the nature of embodied existence in life, death, and afterlife. It is profound in its presentation of the human person fundamentally in relational terms, and its assessment of the human being as genuinely human and alive only within the family of humans brought into being by Yahweh and in relation to the God who gives life-giving breath. This non-negotiable biblical insight is being recovered by some scientists today — e.g., by J. Polkinghorne and W.S. Brown, each of whom has urged that the notion of “soul” be recast in relational terms.⁴

We can press further. First, Scripture outlines a series of qualities of the human person that contrast sharply with the “modern self” derived from dualistic portraits. In his Sources of the Self, C. Taylor finds that, for modern folk, personal identity has come to be shaped by such assumptions as self-sufficiency, self-determination, and self-referentiality (“I am who I am”); that persons have an inner self, which is the authentic self; and that self-autonomy and self-legislation are basic to authentic personhood (Harvard University Press, 1989). Without majoring on the notion of a metaphysical entity of the “soul,” Taylor’s analysis nonetheless intimates how modern, personal identity has been cultivated in the garden of anthropological dualism.

In Scripture, however, we find such emphases as the following: the construction of the self as deeply embedded in social relationships and thus the importance of dependence/interdependence for human identity; a premium on the integrity of the community and thus the contribution of individuals to that integrity; the assumption that a person is one’s behavior; an emphasis on external authority — that is, the call to holiness is a call to a human vocation drawn from a vision of Yahweh’s “difference”; and the reality of dualism vis-à-vis good/evil, resident in and manifest both outside and inside a person. The line from a substance dualism that locates personal essence in the “soul” to this vision of personal identity is not easily drawn.

The point is that the construction of personal identity that pervades modernity is at odds with biblical anthropology at almost every turn, while the witness of Scripture and the findings of neuroscience are converging at significant points.

Second, negatively, we err when we imagine that it is the “soul” that distinguishes humanity from non-human creatures. Aristotle is closer to the biblical tradition in his view that the soul is that in virtue of which an organism is alive (On the Soul 2.1 §§412a-413a10). Given this conceptualization, there is no particular reason to limit the idea of “soul” to the human person. Within the Old Testament, “soul” (Hebrew: nepheš) refers to life and vitality — not life in general, but life as instantiated in human persons and animals. Nepheš is not a thing to have but a way to be. To speak of loving God with all of one’s “soul,” then, is to elevate the intensity of involvement of one’s whole being. Accordingly, the Common English Bible gets it right when it translates “the first and greatest commandment” in this way: “You must love the Lord your God with all your heart, with all your being, and with all your mind” (Matthew 22:37). Morever, in the creation accounts of Genesis 1-2, the Hebrew term used of human beings in 2:7, nepheš, is also used with reference to all sorts of wildlife, to everything “in which there is life (nepheš)” (1:30). This demonstrates incontrovertibly that “soul” (nepheš) is not, under this accounting, a unique characteristic of the human person. Accordingly, one might better translate Genesis 2:7 with reference to the divine gift of life: “the human being became a living person” — or, to quote again from the Common English Bible: “The human came to life.”

Third, thinking still of Genesis 2, it is instructive that the same texts that are silent on the infusion of a human soul into a dust-created body nevertheless distinguish by their use of the term nepheš between a being that has life and lifelessness. This speaks against any dualism that deprecates the body in favor of the soul and against any conceptualization of disembodied human existence in this life or the next. It also contravenes the widely held view that the quality of human life is vested in some thing or quality intrinsic to the individual person and that, in order to speak meaningfully of an afterlife, this “thing” must survive death. The soul does not distinguish human life as human or of particular value, but the graciousness of God does. Scripture situates the human family within the grand narrative of God’s doing; this narrative places a premium on human relatedness to God, humanity, and the cosmos because it is determined by God’s own character; and it is precisely within this narrative that the human creature draws both its value and its reason for being.

Hence, from a vantage point within the biblical narrative, avenues determined by autonomous individualism, interior psychic and/or mental processes, or the behavior of a vast assembly of nerve cells are mistaken, however well-worn they may have become. Although each of these accounts might appear to support a workable portrait of the human person and of human health, none of these carry us far in our concern to address our deepest human questions about what it means to be fully human.

What does it mean to be human? From a perspective within the biblical narrative, the way forward is marked by an account that rejects the necessity of a separate, metaphysical entity such as a soul to account for human capacities and distinctives; that underscores the material location of the human person in relation to the created order; that refuses to reduce personal identity to our neural equipment but rather emphasizes the personal contribution and relatedness of human beings to the human family and the cosmos; and thus that has as its primary point of beginning and orientation the human in a partnering relationship with God.

Further Reading

• W.S. Brown et al., eds., Whatever Happened to the Soul? Scientific and Theological Portraits of Human Nature (Fortress, 1998)
• J.B. Green, Body, Soul, and Human Life: The Nature of Humanity in the Bible (Baker Academic, 2008)
• J.B. Green, ed., What about the Soul? Neuroscience and Christian Anthropology (Abingdon, 2004)
• M.A. Jeeves, ed., Rethinking Human Nature: A Multidisciplinary Approach (Eerdmans, 2011).

Notes

1. P. Churchland, Brain-Wise. MIT Press, 2002: 2
2. S. Blakeselee, “Humanity? Maybe It’s All in the Wiring,” New York Times, 9 December 2003, F1
3. T. Metzinger, “Consciousness Research at the End of the Twentieth Century,” in Neural Correlates of Consciousness: Empirical and Conceptual Questions. ed. T. Metzinger; MIT Press, 2000: p. 6
4. See J. Polkinghorne, “Eschatology: Some Questions and Some Insights from Science,” in The End of the World and the Ends of God. ed. J. Polkinghorne and M. Welker. Trinity Press International, 2000: 29-41 and W. S. Brown, “Cognitive Contributions to Soul,” in Whatever Happened to the Soul? ed. W.S. Brown et al.; Fortress, 1998: 99-125.

Darwin’s finches are some of the most visible and recognizable symbols of evolution in the world today. Biology textbooks feature them prominently, and the National Academy of Sciences has enshrined them in the entrance of their headquarters in Washington, DC. Surely the finches that Darwin collected on the Galápagos islands were a central feature of his evolutionary theory, right?

Lobby of The National Academies Building. Courtesy of CPNAS. Photo by Robert Lautman

Actually, the Galápagos finches are never even mentioned in Darwin’s famous work On the Origin of Species. Nor do they appear in Darwin’s famous notebooks on “Transmutation of Species”, in which he formulated the idea of evolution by natural selection.¹ Even Darwin’s private diary of his voyage on the HMS Beagle only mentions the Galápagos finches briefly in passing.²

It was only in 1845, in the second edition of The Voyage of the Beagle, that Darwin included a tantalizing sentence about the Galápagos finches:

Seeing this gradation and diversity of structure in one small, intimately related group of birds, one might really fancy that from an original paucity of birds in this archipelago, one species had been taken and modified for different ends.³

However insightful this statement may have been, Darwin never published anything else about the Galápagos finches for the rest of his life. Nor did he publically present these birds as direct evidence for this theory of evolution.⁴

If these finches were so important to Darwin’s evolutionary theory, why did he remain silent about them? One of his comments in The Voyage of the Beagle provides us with a clue:

Unfortunately most of the specimens of the finch tribe were mingled together; but I have strong reasons to suspect that some of the species of the subgroup Geospiza are confined to separate islands.⁵

When Darwin was exploring the Galápagos himself in 1835, he had not formulated his theory of evolution yet, and thus he did know what data would be necessary to make definitive conclusions about finch evolution. In particular, he did not keep careful track of which of his specimens came from which islands. Moreover, as was customary among naturalists at that time, Darwin only collected a small number specimens—he brought home only 31 finches and 64 total birds from the Galápagos.⁶

Though Darwin sensed that these birds were truly special, he lacked sufficient evidence to reach any specific conclusions about their evolutionary origins. It would be up to the rest of the scientific community to carry out the necessary empirical research. Subsequent expeditions in 1868, 1891, 1897, and 1905 brought back thousands of Galápagos finch specimens, but instead of unlocking the mysteries of evolutionary theory, the Galápagos finches became a great enigma.⁷

A century after Darwin's voyage, scientists still struggled to explain the staggering variety of finches on this tiny, remote archipelago. By the mid-1930’s, British Museum ornithologist Percy Lowe argued that the finches presented a "biological problem of first class importance", and he told the British Association for the Advancement of Science that the finches displayed a "bewildering diversity, intergradation, and distribution".⁸ Who would be up to the challenge of making sense of such tremendous biological complexity? It was David Lack.

David Lack

Ornithologist David Lack

David Lack had an exceptionally keen eye for bird-watching, and he possessed a passion to match it. By age 15, he had already observed 100 distinct species of birds, and before entering college, authored his first scientific paper. At Cambridge University in the early 1930’s, Lack was disappointed to find that his zoology professors taught “nothing about evolution, ecology, behavior or genetics, and of course nothing about birds.”⁹ In fact, at that time, there were only two professional ornithologists in all of Britain!

Thus David Lack took it upon himself to create his own learning opportunities. As an undergraduate, he became the president of the Cambridge Ornithological Club, traveled to Greenland for a bird-watching expedition, and cultivated a relationship with the prominent biologist Julian Huxley (grandson of Thomas Henry Huxley). Huxley was an inspiring mentor and encouraged Lack to expand his research further by studying tropical birds.¹⁰ Following this advice, Lack embarked on a research trip to Tanzania in the summer of 1934, but his greatest adventure was yet to come.

In 1937, Lack became fascinated by the scientific mysteries surrounding the Galápagos finches. But in order to study their behavior, Lack would need to travel to remote islands halfway around the world. How could he possibly get there? Once again, Julian Huxley was tremendously supportive and raised funds from two prominent scientific societies to pay for his expedition. After a long delay, David Lack and five companions finally set off on their journey.

Instead of residing in comfortable quarters aboard a royal naval ship, Lack’s group subsisted on a shoestring budget, traveled on commercial steamers, and stayed with local settlers. Their experience was definitely not a romantic tale of imperial expedition:

The Galápagos are interesting, but scarcely a residential paradise. The biological peculiarities are offset by an enervating climate, monotonous scenery, dense thorn scrub, cactus spines, loose sharp lava, food deficiencies, water shortage, black rats, fleas, jiggers, ants, mosquitoes, scorpions, Ecuadorian Indians of doubtful honesty, and dejected, disillusioned European settlers.¹¹

Whereas Charles Darwin spent only nineteen days on the shores of the Galápagos, Lack and his crew conducted more than five months of meticulous and exhausting study in the harsh climate. At that time, even the finches themselves provided little solace. Lack wrote,

Darwin’s finches are dull to look at, not only in their orderly ranks in museum trays, but also when they hop about the ground or perch in the trees of the Galápagos, making dull unmusical noises. Only the variety of their beaks and the number of their species excite attention.¹²

Large Cactus Finch on Española Island in the Galápagos Islands

The repetitive tedium requisite for important scientific discoveries is rarely discussed in public, and even today many bright-eyed science students become disillusioned by the painstaking work demanded by their Ph.D. programs. But one of the things that distinguishes great scientists is their unwavering commitment and tenacity in completing major projects. David Lack's efforts were not in vain:

"Despite his personal discomforts (or perhaps because of them), Lack did see something on the Galápagos that no one had ever seen before—natural selection at work among its finches through interspecies competition." ¹³

When the birds’ breeding season ended in 1939, Lack was ready to return to his home in England. But the captive finches that he had brought with him fared so badly on the voyage home that he detoured to San Francisco and put them in the care of the California Academy of Sciences. Turning this mishap into an opportunity, Lack stayed there for five additional months to study the Academy’s enormous collection of Galápagos finch specimens.¹⁴

To complete his systematic research, Lack then travelled across the United States to study the Galápagos finch collection housed at the American Museum in New York.¹⁵ Altogether, Lack examined more than 8000 specimens and specifically measured the length, width, and depth of all their beaks.¹⁶

Lack’s final obstacle was in getting his research published. Though he completed his academic manuscript “The Galápagos Finches—A Study in Variation” in 1940, paper shortages during World War II delayed its publication by the California Academy of Sciences until 1945. Were he only interested in making an original contribution to science, Lack could have stopped here and congratulated himself on a job well-done. However, his motivation sprung from a deeper source:

David Lack's drawing of 14 species of Galápagos finches, p. 19 of Darwin’s Finches

"I did not watch birds primarily for scientific reasons but for sheer enjoyment, and from the age of 15 onward returned day after day in a glow of excitement after seeing a new bird or a new habit." ¹⁷

Lack’s joyful fascination with the Galápagos finches inspired him to continue developing his conclusions long after returning from his expedition. While waiting for his academic paper to be published, he began writing a book that would enable students and the general public to share his excitement about these remarkable birds and the evolutionary processes that shaped them.

First published in 1947, Lack’s book became tremendously influential. Before this time, biology textbooks had never even mentioned the Galápagos finches. But after David Lack’s study, the finches became a primary example of evolution by natural selection, specifically adaptive radiation. Not only did textbooks fully rely on Lack’s findings, they also followed his lead in calling them “Darwin’s finches”, the title of Lack’s famous book.¹⁸

Iconic Finches

What was it about these birds that made them such a prominent symbol of evolution? As Darwin himself pointed out, the numerous Galápagos finch populations each have distinctive beaks, and he speculated that they could have evolved from an ancestral species that came to the islands. But a complete picture of finch evolution would have to wait another hundred years, when David Lack arrived.

During his five months on the Galápagos, including both the rainy and dry seasons, Lack observed that these beak differences enable the finches to subsist on different kinds of food:

The beak differences between most of the genera and subgenera of Darwin's finches are clearly correlated with differences in feeding methods. This is well borne out by the heavy, finch-like beak of the seed-eating Geospiza, the long beak of the flower-probing Cactornis, the somewhat parrot-like beak of the leaf, bud, and fruit-eating Platyspiza, the woodpecker-like beak of the woodboring Catcospiza, and the warbler-like beaks of the insect-eating certhidea and Pinaroloxias.¹⁹

Lack's image of beak adaptations from Darwin’s Finches

Specializing in such different sources of food enables these finches to live in close proximity without directly competing with each other or driving populations to extinction. The fact that so many of these closely related finches are able to co-exist is a remarkable fact in itself. As Lack himself put it, “It is not only the origin, but also the persistence, of new species which require explanation.”²⁰

But it is also fascinating to consider how these birds got to be so different in the first place. How did a finch come to have a beak like a “parrot”, “woodpecker”, or “warbler”? The answer lies in the distinct characteristics of the Galápagos. Because the islands are so remote, no actual parrots, woodpeckers, or warblers ever settled on it. In the absence of these species, the Galápagos finches were able to adopt feeding habits and forms that they would never have taken on a large continent full of other birds competing for food. The isolation of these islands offered just the right conditions for us to see living examples of adaptive radiation.²¹

Conclusion

Considering the immense popularity of the Galápagos finches, it is quite surprising to learn that Charles Darwin himself had so little to say about them. In fact, it was actually David Lack, one century later, who conducted the critical research that immortalized the finches in biology textbooks and popular lore. By naming his landmark book Darwin’s Finches,²² Lack paid homage to the man whose voyage on the HMS Beagle helped transform the study of natural history. But at the same time, Lack also obscured the fact that evolutionary biology is an enterprise conducted by a large community of brilliant scholars, not just the product of one man’s efforts.

This tendency to immortalize “great men of science” has also led many people to refer to modern evolutionary theory as Darwinism, despite the fact that it has substantially changed and developed over the past 150 years. It is important to give credit where credit is due, and if that’s the case, we should seriously reconsider how we refer to the Galapagos finches. Evolutionary biologist Dolph Schluter, who studied the finches several decades after David Lack, had this to say:

I find Lack's intuition really stunning given how little information he had. He's my hero actually… They should be called Lack's finches.²³

In the second part of this series, we’ll explore the fact that David Lack, in addition to being a world-renowned evolutionary biologist, was also a devout Christian. His study of evolutionary theory did not cause him to lose his faith; in fact, he actually converted to Christianity after completing his Galápagos finch research.

For Discussion

Further Reading

• Grant, Peter R.; Grant, B. Rosemary. How and Why Species Multiply: The Radiation of Darwin's Finches, Princeton University Press, 2008.
• Sulloway, Frank J. (Spring 1982), "Darwin and His Finches: The Evolution of a Legend" (PDF), Journal of the History of Biology 15 (1): 1–53.
• Weiner, Jonathon. The Beak of the Finch: A Story of Evolution in Our Time. Vintage Books, 1995.

Notes

1. Sulloway, F. (1983). "Darwin and his finches: The evolution of a legend." Journal of the history of biology 15(1): 32. Darwin’s notebooks on transmutation mentioned Galapagos tortoises and mockingbirds, not finches.
2. Lack, David. Darwin’s Finches. Cambridge University Press, 1947: 9. Confirmed by Sulloway (1983), p5.
3. Darwin, Charles. Journal of researches into the natural history and geology of the countries visited during the voyage of H.M.S. Beagle round the world. London: John Murray. 2d ed. 1845: 379-80. This edition of the book also contained the drawings of four different finches that have become enshrined in biology textbooks and on the walls of the National Academy of Sciences in Washington, DC.
4. Sulloway, p35. Sulloway points out that the first published evolutionary account of the Galapagos finches was not until 1876, by Osbert Salvin: "On the Avifauna of the Galapagos Archipelago." Trans. Zool. Soc. London, 9:447-51.
5. Darwin (1845), p395.
6. Sulloway, p40.
7. Sulloway, p40.
8. Larson, E. J. Evolution's Workshop: God and Science on the Galapagos Islands. New York, Basic Books, 2001: 166-67.
9. Lack, David. (1973) “My life as an amateur ornithologist.” Ibis: 424.
10. Lack (1973), 425-27.
11. Lack (1947), p1.
12. Lack (1947), p11.
13. Larson, 167-68.
14. The California Academy of Sciences sponsored an expedition to the Galapagos in 1905-06 and collected nearly 9000 Galapagos finch specimens (Sulloway, p40).
15. In New York, Lack roomed with the curator of the finch collection—German émigré zoologist Ernst Mayr. By developing this relationship, Lack had close ties with two of the biggest figures in the neo-Darwinian synthesis, Julian Huxley and Ernst Mayr (Larson, 168).
16. Larson, p168.
17. Lack (1973), p424.
18. Larson, p198.
19. Lack (1947), p60.
20. Lack (1947), p158.
21. See Lack’s concluding chapter on “Adaptive Radiation”, pp146-159 of Darwin’s Finches (1947).
22. British ornithologist Percy Lowe originally proposed the name “Darwin’s finches” in 1935, but the name did not catch on until Lack used it in his book. See P.R. Lowe, (1936) "The Finches of the Galapagos in Relation to Darwin's Conception of Species." Ibis, 13th ser., 6:310-321. (Cited in Larson, p287)
23. Schluter, in an interview with Edward Larson, 16 March 2000.

Eugene Dubois

13 years before, in 1877, Dubois had arrived in Amsterdam to study medicine, but always harboring a desire to study the ancestry of modern humans. So, after four years at the University there, he accepted an invitation to go to the University of Utrecht to study comparative anatomy and devote himself to the latest thinking about the origins of the human species. It was during his time at Utrecht (from 1881 to 1887) that Dubois became enamored of Haeckel’s views on human origins, which differed from those of Darwin. While Darwin argued that humans had evolved in Africa, the region in which our closest living relatives—the chimpanzees and gorillas—still live, Haeckel believed that the origins of humanity lay in East Asia. This was so, he believed, because of his own observations of gibbons that walk bipedally when on the ground.

Haeckel also believed that there had once been a large landmass called Lemuria between the continents of Africa and Asia. In his view, Lemuria had since become submerged, leaving the modern islands of Madagascar and the East Indies as its only remains. The idea of submerged continents was not unusual for the late 19th-century, as people struggled to understand the character of biological diversity present in the world and why there were such striking similarities between animals that were geographically dispersed. The geographical distribution of marsupial fossils in South America and Australia is an example of this sort of problem, and one that was not solved until the second half of the 20th century when continental drift reconstructions suggested that ancient marsupials had used Antarctica as a conduit between the other two continents. Not only did such theories make sense of modern distributions, they were confirmed with later discoveries of marsupial fossils in Antarctica.

In any case, in 1888 Dubois joined the army and set out for the Dutch East Indies to pursue his ideas. For the next two years, he would comb Sumatra attempting to locate the hominin remains that Haeckel promised would be there. In hindsight, what Dubois was attempting was something that had never been done before: discovery of hominin material through the tools of archaeological excavation. Up to this point, all of the human fossils had been found on the surface, eroding out of the side of a bank, or as a result of farming. It had not occurred to anyone to go looking for human ancestors.

Now, with his supply of prison workers dwindling due to desertion and fever, he had almost run out of options and was on the verge of failure. Using almost all of his remaining resources, he decided to abandon his excavations on Sumatra and turn to the nearby island of Java. Emboldened by the fact that early modern human fossils had been discovered there (at Wadjak), he arrived and settled in at Trinil, on the banks of the Solo River, in 1890.

Figure 1: Dubois' Pithecanthropus erectus

The very next year, Dubois’ long-standing efforts were finally rewarded, first with the discovery of a skullcap (calvaria) of a hominin cranium, and then with an intact femur (Figure 1). Judging by what he knew of cranial anatomy, Dubois estimated that the skull would have been approximately 900 cubic centimeters (cc) in volume, placing it below even the lowest threshold of modern humans. Further, he noticed that it was not like modern humans in shape, being too long and low. He concluded that it showed “evidence of a form intermediate between man and the anthropoid apes” (Dubois, 1896). Dubois envisioned a sequence of forms in which the gibbon gave rise to a form of chimpanzee called Anthropopithecus sivalensis, which then gave rise to the form represented by the Trinil remains, after which Homo sapiens arose (Turner, 1895).

Dubois spent the next twenty years on the road with his find, trying to drum up support for its place in human prehistory. As with Raymond Dart’s discovery of the first australopithecine thirty-three years later, Dubois did not receive a warm reception. Most critics simply said that he had gotten it wrong and that the femur did not belong to the same individual as the obviously-primitive skull cap. Some of the criticism Dubois suffered could have been mitigated had he been more open to sharing the Trinil materials; but, instead, he allowed very little access to the bones, so that very few people knew exactly what they looked like. Adding to Dubois’s credibility problems was the 1911 “discovery” of Piltdown. This intentional hoax turned the paleoanthropology world on its head for forty years, sending researchers down innumerable rabbit holes. As I noted in a previous post, the Piltdown remains made all of the other hominin finds appear too “ape-like” to be on the road to humanity and informed many opinions about finds such as those from Trinil.

On the other hand, some critics of Dubois’ new hominin claim were vicious, and questioned both his academic abilities and his judgment (Shipman & Storm, 2002)—in addition to the interpretation of the find itself. It was in reference to Dubois’ work that the term “Missing Link” was first used with reference to a particular human fossil, originating with Charles Lyell (1863) and describing palaeontological gaps. And ironically, it was in one of the most stinging criticisms of Dubois’ work that the name that would eventually stick was first used: “Homo erectus.” Eventually, many other finds in the same general area and across Southeast Asia demonstrated that what Dubois had found was a real, previously-unknown hominin form, and the first to colonize the Asian continent and the islands leading off towards Oceania.

Homo erectus across South East Asia:

Figure 2: Sangiran 17

Sangiran

The earliest point at which Homo erectus appears to have begun to colonize the greater East Asian region is around 1.8 million years ago, represented first by the partial child’s skull found at the site of Modjokerto, and then, at around 1.66 million years ago, at the site of Sangiran, in Trinil, where Dubois had made his landmark discovery. This site was rich, yielding the remains of many crania, perhaps best represented by Sangiran 17 (Figure 2), an almost complete skull.

The material from the Sangiran site is very diverse morphologically, with some crania having capacities of as little as 700 to 800 cc, and other, larger heads with volumes in the range of 1000 cc. As with the late Homo ergaster finds from Africa, the remains from Sangiran yielded crania that were still widest at their bases, possessing large brow ridges. Some have thick cranial bones and are very robust (Sangiran 4), while others are very gracile (Sangiran 31). What this variation means is not clear, but most workers believe it represents a very diverse diachronic population (that is, one group living and moving around over a long period) rather than separate species inhabiting the area. The Sangiran site yielded fossil material in an almost continuous succession from approximately 1.66 million years ago to less than 800,000 years ago.

Because the area of the excavations—the Sangiran Dome—is a volcanic deposit, the layers have been securely dated by the ⁴⁰Ar/³⁹Ar method, although questions remain about the historical sequence and distribution of other animals that lived there through the ages (its faunal succession). The problem is that many of the fossils were not found in context, and relating them directly to the stratigraphy is tenuous. Despite this, most workers are comfortable with the earliest hominins in the region being at least 1.5 million years old.

One of the things hampering workers in this region is the comparative paucity of recovered stone tools. Those that have been found suggest a technological stage similar to the late Oldowan design, equivalent to that being created by the Homo ergaster populations inhabiting the area of Dmanisi and East Africa. Unfortunately, none of the tools have been associated with the hominins directly so it is not exactly clear who made them.

Figure 3: Sambungmacan 3

Sambungmacan

Another major find from the area where Dubois brought Homo erectus to light is the cranium from the site of Sambungmachan. This skull was reportedly found in 1977 but was then illegally sold to the antiquities market, where is spent considerable time in different collections before being “rediscovered” in 1998—in a New York nature curio shop called Maxilla and Mandible, Inc. (Delson et al., 2001). This was an almost-complete calvaria (Figure 3), with only part of the base missing. It is equivalent in size to the fossils from Sangiran, with a cranial capacity of around 1000 cc. It has a large brow ridge extending all of the way across the top of the eyes, a long, low cranium with a sloping forehead and a maximum width near the cranial base—all features that are also characteristic of the late African H. ergaster and Sangiran crania. Although we will never know exactly how old this cranium is, its morphology is consistent with that of the material from Sangiran.

Figure 4: Ngandong 6

Ngandong

Later in time, but also located on the Solo River, is the site of Ngandong, excavated by Oppenoorth in the early 1930s. At this site, fourteen calvaria have been discovered, all of which show advanced Homo erectus characteristics: long and low in shape, with thick-bones and a distinctive brow-ridge. (Figure 4). As with the other Indonesian finds, dating the Ngandong material has been problematic. The deposits at the site were originally thought to be around 100,000 years old, but this interpretation was turned on its head in 1996, when Swisher and colleagues claimed that the deposits were no older than between 27,000 and 53,000 years old (Swisher et al., 1996). These age estimations were made on the associated fauna, however, and as Rainer Grün and the late Alan Thorne pointed out, the faunal material does not match the skulls either in color or in texture and is likely not from the same time. Recently, Swisher and colleagues revisited the dating of the site and derived internally-consistent dates of at least 143,000 years before the present (Indriati et al., 2011). As with the Trinil remains, however, there are no associated stone tools.

Homo erectus in China

The Chinese Homo erectus material is very widely scattered and working in the region has presented many difficulties for researchers in terms of transport, language barriers and funding. Consequently, we know less about this region and its previous inhabitants than we do about most other areas of the Old World. Although there are between ten and fifteen sites that have yielded Homo erectus material, I will only touch on the most important ones.

Lantian:

Figure 5: Lantian

In the early 1960s, a cranium and mandible were found in the cave of Lantian, Shaanxi province, whose characteristics matched other remains from China designated as Homo erectus. Paleomagnetic dating has yielded a date no earlier than 1.15 million years ago for the skull, with the consensus being that it is around 800,000 years old. A date of approximately 650,000 years before the present was derived for the mandible. The cranium is heavily encrusted and suffered from postmortem deformation (Figure 5). When reconstituted, it was found to have a capacity of around 780 cc (low for Homo erectus) and the bones on the sides of the head are the thickest yet recorded. At this site some flake tools, mammal remains, and an ash deposit were all recovered, suggesting hunting and control of fire.

Figure 5: Hexian

Hexian

Another almost-complete calvaria was found at Longtandong cave in the province of Hé Xiàn, dated to between 400,000 and 500,000 years ago. This find exemplifies typical Homo erectus in many ways in that it is long and low, with heavy muscle markings toward the base and the rear of the skull (Figure 6). The cranial capacity is around 1000 cc, a third-again greater than that of the Lantian calvaria. Its cranial shape is very similar to those found in Southeast Asia, suggesting that it straddles the Southeast Asian and Chinese boundary.

While both Lantian and Hexian were significant finds, another site in China boasted the single largest collection of Homo erectus fossils ever found at one site, as well as presenting one of the greatest mysteries in paleoanthropology. Tomorrow, in the conclusion of our look at Homo erectus in Asia, we’ll peer into the Zhoukoudian caves and consider how this species fits into the lineage of man.

There are two opposite errors which need to be countered about the fossil record: 1) that it is so incomplete as to be of no value in interpreting patterns and trends in the history of life, and 2) that it is so good that we should expect a relatively complete record of the details of evolutionary transitions within all or most lineages.

What then is the quality of the fossil record? It can be confidently stated that only a very small fraction of the species that once lived on Earth have been preserved in the rock record and subsequently discovered and described by science.

There is an entire field of scientific research referred to as "taphonomy" -- literally, "the study of death." Taphonomic research includes investigating those processes active from the time of death of an organism until its final burial by sediment. These processes include decomposition, scavenging, mechanical destruction, transportation, and chemical dissolution and alteration. The ways in which the remains of organisms are subsequently mechanically and chemically altered after burial are also examined -- including the various processes of fossilization. Burial and "fossilization" of an organism's remains in no way guarantees its ultimate preservation as a fossil. Processes such as dissolution and recrystallization can remove all record of fossils from the rock. What we collect as fossils are thus the "lucky" organisms that have avoided the wide spectrum of destructive pre- and post-depositional processes arrayed against them.

Soft-bodied organisms, and organisms with non-mineralized skeletons have very little chance of preservation under most environmental conditions. Until the Cambrian nearly all organisms were soft-bodied, and even today the majority of species in marine communities are soft-bodied. The discovery of new soft-bodied fossil localities is always met with great enthusiasm. These localities typically turn up new species with unusual morphologies, and new higher taxa can be erected on the basis of a few specimens! Such localities are also erratically and widely spaced geographically and in geologic time.

Even those organisms with preservable hard parts are unlikely to be preserved under "normal" conditions. Studies of the fate of clam shells in shallow coastal waters reveal that shells are rapidly destroyed by scavenging, boring, chemical dissolution and breakage. Occasional burial during major storm events is one process that favors the incorporation of shells into the sedimentary record, and their ultimate preservation as fossils. Getting terrestrial vertebrate material into the fossil record is even more difficult. The terrestrial environment is a very destructive one: with decomposition and scavenging together with physical and chemical destruction by weathering.

The potential for fossil preservation varies dramatically from environment to environment. Preservation is enhanced under conditions that limit destructive physical and biological processes. Thus marine and fresh water environments with low oxygen levels, high salinities, or relatively high rates of sediment deposition favor preservation. Similarly, in some environments biochemical conditions can favor the early mineralization of skeletons and even soft tissues by a variety of compounds (eg. carbonate, silica, pyrite, and phosphate). The likelihood of preservation is thus highly variable. As a result, the fossil record is biased toward sampling the biota of certain types of environments, and against sampling the biota of others.

In addition to these preservational biases, the erosion, deformation and metamorphism of originally fossiliferous sedimentary rock have eliminated significant portions of the fossil record over geologic time. Furthermore, much of the fossil-bearing sedimentary record is hidden in the subsurface, or located in poorly accessible or little studied geographic areas. For these reasons, of those once-living species actually preserved in the fossil record, only a small portion have been discovered and described by science. However, there is also the promise of continued new and important discovery.

The forces arrayed against fossil preservation also guarantee that the earliest fossils known for a given animal group will always date to some time after that group first evolved. The fossil record always provides only minimum ages for the first appearance of organisms.

Because of the biases of the fossil record, the most abundant and geographically widespread species of hardpart-bearing organisms would tend to be best represented. Also, short-lived species that belonged to rapidly evolving lines of descent are less likely to be preserved than long-lived stable species. Because evolutionary change is probably most rapid within small isolated populations, a detailed species-by-species record of such evolutionary transitions is unlikely to be preserved. Furthermore, capturing such evolutionary events in the fossil record requires the fortuitous sampling of the particular geographic locality where the changes occurred.

Using the model of a branching tree of life, the expectation is for the preservation of isolated branches on an originally very bushy evolutionary tree. A few of these branches (lines of descent) would be fairly complete, while most are reconstructed with only very fragmentary evidence. As a result, the large-scale patterns of evolutionary history can generally be better discerned than the population-by-population or species-by-species transitions. Evolutionary trends over longer periods of time and across greater anatomical transitions can be followed by reconstructing the sequences in which anatomical features were acquired within an evolving branch of the tree of life.

I am glad to have the opportunity to dialogue with Dr. John Hammett. In addition to our shared Christian faith and our shared lack of expertise in evolutionary science, we have in common one of our teaching and scholarly foci: the nature of human persons. Dr. Hammett approaches this topic as a trained theologian, whereas I approach it as a philosopher. However, on a topic such as this one, those disciplinary boundaries can get smudged a bit when the discussants approach the matter from the standpoint of a biblically-rooted Christian faith. Indeed the issue is of such importance and complexity that I would welcome continued conversation with Dr. Hammett beyond this initial exchange.

The Christian Scriptures teach that we human beings have been created in God’s image. What does that mean? I am in substantial agreement with Dr. Hammett on this question. While I think that bearing God’s image involves our having or having a potentiality for certain basic psychological capacities that we associate with the term “person”, it has to do even more profoundly with our specific capacity for relationship with God. Indeed, I would go further and say that it is not just our having this capacity that makes us divine ikons, it is also the fact that God has activated this capacity—He has given the precious gift of His self-disclosure to us. Further still, it has an eschatological dimension, based on the revealed promise of a future development and perfection of each of us, and so by implication, of human nature itself, by almighty God. We are in the process of becoming fully human: beyond a descriptive biological or even psychological notion of human nature lies a teleological one—not a telos of nature but of God's loving purposes for us. Despite our unequally born deficits—physical, cognitive, emotional, and moral/spiritual—we are destined for a fuller, supernatural realization of our common nature.

That we are in these ways God’s image bearers is a (wonderful!) teaching of our faith. The Scriptures also speak in various places of the human “soul.” The idea of the soul seems clearly connected to the idea that we are divine ikons. But here we should tread carefully. It is of course not unique to the Hebrew and Christian Scriptures to use some such singular term to refer to that which is most distinctively human and that by virtue of which we are able to survive the death and decay of our bodies. But it is one thing to use the term as a kind of placeholder for whatever it is about us that enables us to be, feel, and act in distinctively human ways in this life and to survive death into the next; it is another thing to link the term to a specific metaphysical account of the matter, such as might say whether the soul is a kind of thing or substance, what kind of thing it is, and exactly how “it” relates to the human “body.”

It is (and always has been) very common for Christians to invest the term “soul” as it used in Scripture with such a metaphysical account. As these fellow Christians understand it, when the Bible speaks of my soul, it is referring to an immaterial substance that is, in the final analysis, the thing that I am. I have my body (by interacting directly with it and only with it among physical objects), but I am my soul. Many will add that, after my death and prior to the resurrection of the dead, I will exist in a completely disembodied state—a naked soul, as it were.

However, I believe it is a mistake to interpret Scripture as teaching or implying any such metaphysical account of the underpinnings of our distinctively human personal attributes or our capacity for surviving death. Now, after reflecting on the matter, we might conclude that the only way these Scriptural teachings could be true is for such a metaphysical account to be true, as well—an account in which we are immaterial substances, entirely separate from our bodies. Indeed, many have thought hard about it and have drawn just such a conclusion, and it is not hard to see why they find it tempting to do so. But to do so is to make a disputable philosophical inference; it is not a teaching of the faith.

The general perspective of BioLogos, which I embrace, is that theorizing about the underlying nature of the soul is best done by trying to read God’s Two Books (His Word and His Works) in tandem. Both Books have a great deal to say about us, and, as common products of an infinitely wise and loving Creator, what they say must ultimately be in harmony. As with any attempt to understand something deep and wondrous in God’s Creation, we should proceed with humility and carefulness and be prepared to rethink familiar and received ideas.

Spelling it out just a bit, the common Christian understanding of what it is to have a soul involves the yoking of two radically different things, a functioning human (wholly material) body and an immaterial mental thing that is the direct bearer of psychological properties such as self-awareness, emotions, and thoughts, and is that which chooses in accordance with desires and purposes. In short, a complex biological machine and a pure subject/purposive agent which interface in the brain. I want to acknowledge that this is a very natural perspective to have, quite apart from Christian revelation (hence its popularity among humans generally). It is very natural because our psychological abilities seem, introspectively, to be plainly something more than mere resultants of impersonal physical particle interactions, however numerous and complex these are within the human brain.

We can design highly sophisticated computers that process complex bodies of information with extraordinary speed, but no computer is a subject, or has a point of view. As philosophers of mind like to say, there is nothing “it is like” to be a computer in the way that there is something “it is like” to be a conscious subject. Put another way, no mere computer is a conscious, experiencing subject, having a point of view from which it regards and interacts with its environment. Neither do computers make autonomous choices in the face of competing moral and self-interested motivations, and so on. It seems but a short step from this observation to the conclusion that human persons (and thinking/desiring/choosing things more generally) must be fundamentally different sorts of things: fundamentally distinct capacities must reside in fundamentally distinct kinds of substances (mental and spiritual substances as opposed to physical substances, however complex).

I have just described how matters appear from the ‘first-person perspective’ of conscious experience and self-awareness. Let me be clear that I take such evidence very seriously: I know my own conscious thoughts and experiences better than I know any scientific theory,—even a very well-attested one—as all of our theories are at bottom built on information we derive from our experiences. So awareness of the distinctive character of conscious experience is part of what is given to us in the Book of God’s Works, since we are a part of that Book.

But alongside that ‘first-person’ data, we have had an explosion of relevant information coming from the ‘third-person’ perspective of the natural sciences, specifically evolutionary and developmental biology and cognitive neuroscience. This information, while still incomplete and only imperfectly understood, sheds light on the deep natural history of humans and present-day animals; the processes by which individual organisms of any species develop from inception to maturity; function-specific neural structures and processes that sustain and help regulate the unfolding first-person perspective of conscious agents; and finally, observed correlations between increasing complexity of neural structures and increased psychological complexity. This last correlation between structural and cognitive complexity is evident both when examining individuals as they develop, and when making comparisons across sentient species.

I suggest that this third-personal scientific information does not comport well with the two-substance or dualist metaphysical account of human persons. The fundamental problem is that our sciences point to continuous processes of increasing complexity, but the two-substance account requires the supposition of abrupt discontinuity. The “coming to be” at a particular point in time of a new substance with a suite of novel psychological capacities would seem to be a highly discontinuous development, both in large-scale bio-geological time and within the development of individual organisms.

Since souls as purely immaterial things would lack parts, we cannot make sense of the accumulation or diminishment of capacities by proposing increased or decreased structural complexity within the bearer of such capacities. And it just seems implausible to suppose that all the necessary basic capacities for, say, calculus problem-solving are there in the soul from the beginning, awaiting only physical maturation in the body in order to become activated, but still not directly dependent on that maturation. It seems rather that psychological capacities arise and develop in tandem with the development of the brain and nervous system.

Of course, it is possible for the soul-body dualist to retrench: we might offload to the brain ‘side’ of the divide some of the psychological functioning that, prior to the advent of neuroscience, we might have mistakenly thought belonged to the soul. But that tack risks (as neuroscience progresses) reducing the soul to a simple, immaterial object that is radically incomplete, merely a “bearer of consciousness” that enables personal identity over time and through death.

Despite the fact that such future retrenchment would seem to be required, this kind of dualism remains tempting for the Christian thinker. Why? The obvious answer is that it can seem to be the only way to accommodate our specifically Christian data that human beings are not mere machines: our thoughts, emotions, goals, and intentions are deep, not superficial features of ourselves; they confer a dignity upon us that makes us suitable bearers of the divine image such that human beings, after our skin has been destroyed, will yet see God. (Job 19:26). But is it true that the coherence of Christian theology requires this account? And if coherence of Christian theology does not require this account, which account might be the best one?

Tomorrow, in Part 2, I will address this question.

In the previous post in this series, we explored how evolution can force science into making predictions that seem counter-intuitive. For cetacean (whale) evolution, we saw that the preliminary lines of evidence (the fact that whales are vertebrates, and mammals, for instance) pointed to the prediction that modern whales are descended from four-limbed, land-dwelling ancestors. As we then noted:

Instantly this prediction raises a host of uncomfortable questions: where did their hind limbs go? How did they acquire a blowhole on the top of their heads when other mammals have two nostrils on the front of their faces? How did they transition to giving birth in the water? What happened to the teeth of the baleen whales? What happened to the hair characteristic of mammals? and so on. In some ways, evolutionary thinking about whales creates more difficulties than it appears to solve.

And yet, these difficulties are the stuff of science. If indeed our “educated guess” of terrestrial, tetrapod ancestry for whales is correct, the evidence will show that these transitions, challenging though they may seem, did indeed occur on the road to becoming “truly cetacean”.

We have already discussed hind limb and hair loss in whales, citing evidence from embryonic development in modern whales that shows how hair and hind limbs develop early in their embryogenesis, but then are lost at later stages. We now turn to one of the remaining questions: tooth loss in the lineage leading to modern toothless whales (order Mysticeti). To obtain their food these whales pass seawater through a baleen, a large sieve-like structure that filters out plankton, small fish and other food items. Some recent genetics sleuthing has investigated a portion of this riddle, and adds further details to the story of how the baleen whales came to be.

Evolution: A Theory with Bite

If indeed modern whales are descended from ancestral, four-limbed, terrestrial ancestors, then those ancestors, like mammals in general, had teeth. Modern toothed whales (order Odontoceti) have retained those teeth to the present day, but baleen whales have adopted a new way of life as filter-feeders. Researchers were curious to see if traces of a “toothed past” could be found in the genomes of modern baleen whales, so they went hunting for remnants of genes devoted to making teeth. Such defective gene remnants would be examples of pseudogenes, and we have discussed pseudogenes previously in this series. While pseudogenes in and of themselves are powerful evidence for evolution, pseudogenes that are “out of place” are especially so. One such example we have seen before is the human vitellogenin pseudogene, the remains of a gene used for yolk production in egg-laying organisms found in the exact location in the genome that evolution would predict for it. As mammals that receive embryonic nourishment through a placenta, we have no need of egg-yolk genes. Similarly, baleen whales have no need for genes responsible for making teeth, and finding the remnants of such genes would make a strong case for an evolutionary origin of baleen whales as the modified descendents of toothed whale ancestors.

Independent Lines of Evidence, but Contradictory Stories?

Some of the genes known to be used in all mammals for tooth formation were the obvious candidate genes to start with: the products of the ameloblastin, amelogenin, and enamelin genes are all used in the formation of tooth enamel, the hardest structure in the vertebrate skeleton. Researchers went looking for these genes in several Mysticete (i.e. toothless whale) species. The results showed that all the species studied did indeed have these three genes present as pseudogenes (and more specifically, as unitary pseudogenes, a special class of pseudogene we have discussed in detail previously). Finding these genes as pseudogenes in toothless whales was exactly what evolution predicted, but there was a catch: none of the mutations that removed the functions of these three genes were shared between different species, suggesting that these genes lost their function independently in the species studied. This finding was at odds with data from the fossil record, which suggested that teeth were lost only once, and early in the lineage leading to all modern toothless whales. So, the researchers seemed to have two lines of evidence that at face value contradicted each other. The fossil record suggested that tooth loss occurred once in the common ancestor of all toothless whales, but these three genes seemed to have been inactivated independently, several times over, suggesting that loss of teeth should be happening later in Mysticete evolution, and more than once.

One proposed explanation for the apparent discrepancy (among several put forward) was to predict that a fourth gene required for enamel formation was lost early in Mysticete evolution. The loss of any one gene necessary for forming enamel would be enough to prevent the process altogether. In this case, the loss of this fourth gene would prevent tooth enamel from forming, even though the genetic sequences of the other three enamel genes would still be intact. Once enamel function was lost, random mutations in the remaining enamel genes could then accumulate later in Mysticete evolution after speciation in this group was already underway. To test this hypothesis, the research group went hunting for other enamel genes in toothless whales.

Signature in the SINE

The smoking gun for tooth loss in Mysticetes turned out to be exactly what was predicted: a fourth gene, necessary for enamel production, and mutated with the same inactivating mutation in all modern toothless whales. The gene in question, named enamelysin, was destroyed when a mobile genetic element called a SINE transposon inserted into it, breaking it into two halves and removing its function:

The fact that the same SINE insertion mutation at an identical location is found in all modern Mysticete species indicates that this mutation happened once in a common ancestor and then was inherited by the entire group. Since this must have occurred early in the evolution of toothless whales in order to happen in the common ancestor of the entire group, the picture from the genetics and the fossil record match. Once again, findings in one discipline (in this case, paleontology) can be used to make very detailed predictions about what another, unrelated discipline (comparative genomics) should reveal. These results are also entirely consistent with the observation, made in the 1920s, that toothless whales form tooth buds during embryogenesis that are later reabsorbed prior to the point when the deposition of enamel would begin. As with the hind limb story in whale evolution, lines of evidence from genetics, paleontology and embryology converge to support the hypothesis that modern toothless whales descend, through modification, from toothed ancestors.

In the next post in this series, we’ll examine a few more lines of evidence for whale evolution, and extend our discussion to converging lines of evidence for the evolution of our own species.

For further reading:

Meredith, R.W., Gatesy, J., Cjeng, J., and Springer, M.S. (2011). Pseudogenization of the tooth gene enamelysin (MMP20) in the common ancestor of extant baleen whales. Proceedings of the Royal Society B: 278 (1708); 993 – 1002. Available online: http://rspb.royalsocietypublishing.org/content/early/2010/09/16/rspb.2010.1280.full.pdf

Ridewood, W.G. (1923). Observations on the skull in foetal specimens of whales of the genera Megaptera and Balaenoptera. Philosophical Transactions of the Royal Society of London B: 211; 209 - 272. Available online: http://rstb.royalsocietypublishing.org/content/211/382-390/209.full.pdf

See Related Posts in the sidebar

In our previous post, we examined processed pseudogenes – transcribed gene copies that randomly insert into genomes. Unitary pseudogenes, however, are different: unlike processed pseudogenes, they are unique sequences in genomes, and not copies. They have the features one expects of “real” genes: regulatory sequences, introns, and protein coding sections – but with mutations that prevent them from being transcribed or translated. Like buildings in various states of repair, there is a similar range for unitary pseudogenes. If they have only been recently inactivated, they will be largely intact – like a recently abandoned building with a few broken windows. Others are further along in their degradation, like a stone building without a roof and grass growing up through the floor. Some are so far gone that one needs to peel back the turf to search for what remains of the foundation. Despite their various states of disrepair, they remain recognizable – in some cases, they can persist for millions of years before they slowly mutate beyond recognition.

The reason for these defective genes is straightforward: the organism that had the original mutation that removed the function of the gene was not significantly impacted by the loss. One example I have previously discussed is the human GLO pseudogene. The functional GLO gene is part of the biochemical pathway for making vitamin C, something that humans and other primates are not able to do: if we don’t get enough in our diet, we get scurvy. In an environment with adequate dietary vitamin C, however, the loss of the GLO gene is no big deal – and mutations that remove its function would not have been a disadvantage. The mutations that remove GLO function in humans are the same mutations we see in other species – they are an example of mutations in a nested hierarchy, the type of pattern that relatedness produces. This indicates that the mutations happened once, in a common ancestral species, and have been inherited by several species that descend from that ancestor, ours included.

So, what’s a defective gene like you doing in a species like this?

While it makes sense that mammals ought to be able to make vitamin C (even if humans and other primates cannot), in some cases pseudogenes seem much more “out of place.” One example from the human genome that we have discussed in the past, is the vitellogenin gene, a gene required for egg yolk formation in egg-laying organisms. This gene is present in the human genome as a pseudogene, even though humans are placental mammals – human embryos are nourished through a placenta, not egg yolk. This pseudogene was located in the human genome by predicting that its genomic location relative to its neighboring genes would be retained for a long time, even after its inactivation. Accordingly, researchers found a functional vitellogenin gene in the chicken genome, and noted the genes on either side of it (let’s just call them “Gene A and Gene B” for convenience). Gene A and Gene B are also side by side in the human genome, so the researchers looked between them for the signs of vitellogenin gene remains – and found them in that precise spot, still visible despite approximately 300 million years since we last shared a common ancestor with chickens:

Other examples like this abound: whales, for example, have unitary pseudogene remnants of genes devoted to an air-based sense of smell, even in cases where the whale species in question does not have an olfactory organ. A second example from whales are pseudogene remnants of visual pigments adapted for wavelengths of light found in terrestrial settings, not aquatic environments. These examples make perfect sense in light of the terrestrial ancestry of whales, but are challenging to account for from an antievolutionary perspective.

Pseudogenes: evolution’s silver bullet?

Unitary pseudogenes with shared mutations in nested hierarchies among related species are far from the only evidence for evolution, and are not even necessarily the line of evidence most convincing to specialists. Specialists can see the broad pattern of multiple lines of converging evidence that support common ancestry to an extent non-specialists cannot easily appreciate. Unitary pseudogenes, however, are valuable tools for demonstrating a sampling of those lines of evidence, and providing a window into the world of comparative genomics that, to paraphrase Dobzhansky’s famous quote, would make absolutely no sense except in the light of evolution.

Yes, the implications of unitary pseudogenes such as these are easy for even non-specialists to grasp: whales have the defective remnants of genes adapted to terrestrial vision and air-based smelling because they descend from terrestrial ancestors. Placental mammals, including humans, have a defective remnant of a gene used to make egg yolk because they descend from egg-laying ancestors. Unitary pseudogenes share identical mutations across related species because they were inactivated in a common ancestor, and were inherited by every species that descended from that ancestral species.

No special training in genetics is required to appreciate the strength of the evidence that these examples provide. Nor does it require special insight to see that attempts made by antievolutionary groups to refute this evidence face an uphill battle. Its daunting nature notwithstanding, some have undertaken just that task, since the evidence is too compelling to ignore, and too risky to leave unanswered.

Bringing it together: antievolutionary approaches to pseudogenes, unitary and otherwise, miss the mark

Now that we have covered significant ground with respect to what various classes of pseudogenes are and how they arise, we are now able to properly evaluate antievolutionary arguments put forward in an attempt to discredit these lines of evidence for evolution. Attempts to discredit unitary pseudogene evidence generally have one or both of the following two approaches, which we will evaluate in turn:

Approach 1: Discuss rare examples of processed pseudogenes that have acquired function, and imply that all pseudogenes, including unitary pseudogenes, will similarly be shown to have function.

This approach is a fairly common one in the antievolutionary literature, and examples abound. We have examined previously how processed pseudogenes may, in rare cases, acquire a function and come under selection. Note well: the vast, vast majority of processed pseudogenes are not functional and are slowly mutating beyond recognition as DNA not under selection. While rare examples that have acquired function are very interesting from a scientific perspective, they do not “confer functionality” on the remainder of processed pseudogenes, let alone on unitary pseudogenes.

The other issue with this argument is that in many cases we know what the function of the unitary pseudogene once was. We know what the function of vitellogenin is, for example – and we can find this gene in modern-day egg-laying animals. When we see the remnants of this sequence in the human genome it is a stretch to argue that it has another, as of yet unknown function. When we see the human pseudogene sitting between two other genes in the human genome the same order as we observe in the chicken genome, it stretches credibility well past the breaking point.

Approach 2: Claim that unitary pseudogenes with mutations shared across species are the result of non-random mutations that occurred independently in the two species, and are not inherited from a common ancestor.

This argument, though having an appearance of validity, is similarly doomed to frustration. While mutations are not entirely random (certain regions of the genome mutate more readily than others) there is no known mechanism that could create the precise, repeated pattern of shared mutations we observe between related species. The most significant attempt to mount this type of argument against unitary pseudogenes in general was directed at the GLO pseudogene, and I have already discussed the specific details of why that attempt was inadequate. No refinement of that argument, to my knowledge, has been put forward since.

In summary, pseudogenes in general, and unitary pseudogenes in particular, remain a significant thorn in the side of antievolutionary groups. In the next post in this series, we’ll cast our net wider and explore an example of how multiple, convergent lines of evidence support evolution, often in unexpected ways.

For further reading:

http://biologos.org/blog/signature-in-the-pseudogenes-part-1
http://biologos.org/blog/signature-in-the-pseudogenes-part-2
http://biologos.org/blog/a-tale-of-three-creationists-part-3

Humanity is marked by the biological capacity for musicality. Every known culture has something like music. Understanding how we experience and create music in the present gives us clues to why and how music emerged as one of the defining features of human culture (and, therefore, of humanness itself) in the past. But thinking carefully about music and evolution can also help us reassess how we use music now: in the wider culture, collectively as the church, and even within our own homes. In a nutshell, then, this essay will examine how views on evolution impact how one assesses music’s effects and meaning. In many cases, problematic views about evolution and artistic creativity result in problematic views about music, but my argument is that an appropriate evolutionary view of music—one that looks at how music becomes meaningful within social relationships—is a view that actually enriches our appreciation of this most human endeavor, rather than trivializing it. In this first part I explore common discourses about the meaning of music and their relationship to ideas of creation. In part two next week, I suggest that understanding the role that music played in our biocultural evolution helps correct some of the myths that have made their way into popular discourse, especially with the growing popularity of trying to understand music via neuroscience.

Let’s begin by looking at a couple of popular ways of answering the question, “Where does musical meaning come from?” beginning with the idea that “music is in the ear of the beholder.” One thing that is clear from years of teaching classes of first-year university students is that they are musical relativists. They have ‘their’ music that they enjoy and even use to demark their identities, but are perfectly willing to allow others to like other music. After all, music is all about enjoyment, right? Historically, this cultural trope developed out of the post-Kantian argument of musical autonomy, the often-fashionable argument that music’s meaning is strictly musical and does not relate to other parts of the world. It is also reflected in Steven Pinker’s argument that music is ‘auditory cheesecake’. For Pinker, music used to be useful for things like attracting mates, but now we have evolved out of needing music: it’s not necessary, but is a nice extra. I might like cheesecake, but you might prefer ice cream. Either way, it won’t change the survival of the species, so we can enjoy what we like. This argument may have a harder time standing up when music is used as a means of torture at Guantanamo Bay, but it remains popular none-the-less. Like many ideas of creation and the arts, the idea of music as primarily pleasure (determined by individual taste) is a post-Enlightenment development.

This musical relativism takes a slightly more exacting form in another popular idea, that meaning is embedded within the ‘music itself’ not in the taste of the listener. This view of meaning is the starting point of Plato and Aristotle’s disagreement about the effect of certain modes, the disagreements in the early church about the usage of certain musical instruments, and the arguments of the detrimental moral impact of certain forms of popular music (which, by the way, is an argument not just limited to the 20th or now 21st centuries). It is also the foundation of the statement from one of my former conductors that if we played well enough, we would summon up the ‘spirit of Haydn’. In other words, ‘proper’ participation can reveal the meaning of the work—be that the composer’s meaning or another idealized meaning.

Musical autonomy in this case refers to the view that music stands apart and has no relations or meaning outside of itself. Many philosophers and musicologists rely on this view in an unreflective way, represented by Peter Kivy’s statement that music “is a quasi-syntactical structure of sound understandable solely in musical terms and having no semantic or representational content, no meaning, and making no reference to anything beyond itself”¹. For Kivy, the heart of the autonomy argument is that music is completely self-contained. Such a view is possible because of the historical development of ‘absolute music’, referring to music without a text or narrative, typified by the development of the symphonic form in the late 18th century. It is no accident that between 1750-1850, the form of the symphony developed, Kant theorized the idea of genius, and Schopenhauer claimed music to be “pure will.” In the 19th century, music came to be considered the highest of the arts, and even at the turn of the 20th century Kandinsky claimed that all art should try to achieve the autonomy and abstraction of music.

The idea of musical meaning somehow residing within the musical work is based on an assumption that the more one can isolate and analyze something, the more can be known about it. We can certainly learn much about a rock or plant by isolating it and putting it under a microscope, and those who take music to be autonomous believe that music can also be known most thoroughly by placing it ‘under the microscope’ through close analysis of a score or recording, or through close listening. It is through such pseudo-scientific analytical acts that knowledge about music is thought to be accessed. This is also the guiding ideology of ‘music appreciation.’ But while much can be gained by close examination of rocks or music, much more can be gained by studying how a rock or (especially) music is used by people—a central point to which we will return.

It is more than a little ironic, then, that a further example of the belief in an intrinsic musical meaning is the argument that music is ‘universal’; that is, that at least some music can cross cultural barriers and mean the same thing to all people. Often this view assumes a primacy of the Western canon, as it is believed that Mozart has a universal meaning but Chinese qin (zither) music does not. In a globalized world where many cultures listen to and value Mozart, people who do not share a common language or view of the world may find Mozart a common point of contact. But finding Mozart a point of contact is not caused by the music having a universal meaning. Rather, it is an example of the way music can become a shared space where people enter into a relationship via art. The West-Eastern Divan Orchestra (a project of Daniel Barenboim and the late Edward Said) is an example of music being a common ground where people from different views of the world can connect, not an example of universalized meanings of music.

Indeed, there are many situations when music’s meanings are not shared, showing that meaning is most definitely not universal. Martin Lodge recounts the encounter of Dutch explorers and the Maori people of New Zealand in 1642. When the parties got close enough to see (and hear) each other, each group signalled with trumpets. The Dutch, thinking they were successful in making contact, sent a boat of unarmed sailors to shore. The boat was met by Maori warriors who killed more than half of the sailors. This misunderstanding was caused by not sharing a musical meaning: “The Maori trumpeting in this case was the music of war, an invitation to fight. On the other hand the Dutch trumpets played a variety of tunes intended to be welcoming.”² Musical meanings are often shared, but are not universal or ‘in the music’.

As we have begun to see, considering music as culturally embedded lets us recognize something quite different from the arguments that musical meaning is either subjective or encoded within the music itself. Music does allow for subjective response, but not truly autonomous response—our experience of music occurs within the bounds of cultural norms. Since music’s significance cannot be abstracted from it’s embeddedness within social relationships, an attention to culture and human intentionality (not just a reductionist sense of biology) must inform the ways that music is studied, whether in contemporary culture, in neuroscience, and with reference to human evolution. Unfortunately even many Christian views of music have relied upon some of these problematic views of musical meaning, aligning ideas like individual artistic genius and the “meaning in the music” concept with theologies of creation ex nihilo. As Bruce Ellis Benson discusses in an essay in the journal Verge (and in a shortened version here at BioLogos), this combination or paralleling of genius and ex nihilo creation complicates the church’s understanding not only of music, but also about the Creator God, downplaying the essential element of community and interpersonal relationship inherent to both.

Next week, we’ll look at a similar tendency to abstract and quantify the way music makes meaning in the burgeoning field of neuroscience (from the “Mozart Effect” to fMRI scans), and return to the way that thinking about music within the evolution of human culture might give us a deeper appreciation of music—even of worship—within the church. In the meantime, here are some questions to consider:

How do my own assumptions of the way music is meaningful affect the ways I conceive of and use music?

Are there negative consequences stemming from these assumptions?

How have problematic views of musical meaning affected the use of music as personal identity? Or in the church? Or in the media? Or in popularized science?

Notes

1. Kivy, Peter (1990) Music Alone (Cornell University Press: Ithica, NY): p. 202.

2. Lodge, Martin (2009) 'Music Historiography in New Zealand' in ed. Zdravko Blazekovic, Music's Intellectual History (RILM: New York): p. 627.