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An Evangelical Geneticist’s Critique of Reasons to Believe’s Testable Creation Model, Pt. 1

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November 6, 2010 Tags: Genetics

Today's entry was written by Dennis Venema. Please note the views expressed here are those of the author, not necessarily of The BioLogos Foundation. You can read more about what we believe here.

An Evangelical Geneticist’s Critique of Reasons to Believe’s Testable Creation Model, Pt. 1

Today's post comes from a longer essay by Dr. Venema. Full footnotes can be found in the essay.

One serious critique of young-earth creationist attempts to explain the natural realm is that their explanations, typically rooted in religious dogma, have no flexibility to adapt and self-correct as knowledge increases.

-Hugh Ross
More Than a Theory, p. 20

Introduction

Reasons to Believe (RTB) is the most influential Old-Earth Creationist organization in North America. While RTB supports a mainstream scientific position on cosmology and the age of the earth, RTB rejects evolutionary biology. Specifically, RTB denies that humans share ancestry with other forms of life, such as Neandertals or chimpanzees. RTB also claims that all human are the descendents of a single, specially created couple who lived about 50,000 years ago. RTB has expounded a framework called the “Testable Creation Model” in three major books published in the last five years: Who Was Adam? was published in 2005; Creation as Science was published in 2006, and More Than a Theory was published in 2009. Furthermore, RTB claims that this model is scientifically robust.1 This same period however, has also seen the publication of much genetic data relevant to assessing human common ancestry. This paper will examine the interaction between RTB literature and several lines of genetics-based evidence for common ancestry. In so doing, I will address the scientific robustness and reliability of the RTB model. RTB welcomes such critique from qualified scholars in their works as a means of improving their model.2 This critique, while forthright, is offered without animosity and in good faith. It is my hope that RTB will find it useful for correcting several serious flaws in their approach to human origins.

A recent history of primate comparative genomics

When the human genome project (the endeavor to determine the complete DNA sequence of every human chromosome) was completed in 2003, the equivalent chimpanzee genome project was already underway. Just prior to the completion of the human project (from about 2002 on), detailed comparisons of large stretches of DNA between humans and chimpanzees became possible as both genome projects progressed. As the data came in, a range of estimates for the precise amount of identity between the two genomes was published in the mainstream scientific literature (Table 1).

Such estimates took two forms: measuring single-nucleotide differences in sequences found in both genomes while omitting inserted or deleted sequences (so-called “indel” mutations, because it may be difficult to determine if a difference is due to an insertion or deletion), or estimates combining both sources of variation. In the years preceding the completion of the chimpanzee genome in 2005, partial-genome comparisons repeatedly estimated the two genomes to be over 98% identical when omitting differences due to indels. Two pre-2005 studies took indels into consideration as well: Britten (2002) estimated the two genomes to be 95% identical, whereas Anzai et al. (2003) found only 87% identity. This paper examined a chromosomal region that contains immune system genes, and was not thought to be representative of the genome as a whole. This prediction was borne out in 2005 when the completed human and chimpanzee genomes were compared (2.9x109 DNA base pairs). The final tally was 98.77% identical when indels were omitted and 95% identical when indels were included. A second paper published in 2005 examined 1.85x107 DNA base pairs found in the portions of the chromosome that specify proteins, and found even higher identity (99.4%) in these sequences.

The RTB model and comparative primate homology: overview

A key tenet of the RTB model is that humans do not share ancestry with other forms of life. As such, RTB has invested considerable effort in reinterpreting human / chimpanzee genomic homology comparisons for their constituents. A notable feature of the RTB model is the claim that the whole-genome, human / chimpanzee homology value is in fact 85-90%, not 95-99%.3 As we have seen, comparisons between the human and chimpanzee genomes progressively improved in the early 2000s, culminating in the landmark whole-genome comparison of 2005. The fact that these data emerged over time allows us to investigate how RTB responded over the same time period, and as such examine the reliability of the RTB model as new data became available that were at odds with one of its non-negotiable claims.

The RTB model and primate genomics (2005): Who Was Adam?

Like comparative primate genomics, the RTB creation model also hit a milestone in 2005 with the publication of Who Was Adam? (WWA) by RTB scholars Fazale Rana and Hugh Ross. This book narrowly predates the pivotal 2005 whole-genome comparison paper. Unlike two later RTB books (see below) this book discusses research-to-date on human-chimpanzee comparative genetics in extensive detail. (p. 212-215) WWA carefully distinguishes between estimates based on including or excluding indels, as well as chromosomal or mitochondrial DNA. However, WWA made a questionable claim when it states:

“The most comprehensive genetic comparisons indicate that humans and chimpanzees share genetic similarity closer to about 85 percent than to 99 percent. From an evolutionary perspective, if a 99 percent genetic similarity reflects a close evolutionary connection, then an 85% genetic similarity distances humans from chimpanzees.”(p. 223)

This assertion, however, was already at odds with the conclusions of the 2004 Chromosome 22 Consortium paper (Table 1), a paper that is cited in WWA as support for differences in human-chimpanzee gene expression. (p. 222) At the time WWA was published, RTB expected future genomic comparisons to widen the gap between humans and chimpanzees. (p. 223)

The RTB model and primate genomics (2006): Creation as Science

In early September 2005, a full comparison between the completed chimpanzee genome and the human genome was published in the prestigious journal Nature. This landmark paper used a sample size of 2.9x109 base pairs: it covered virtually the entire genomes of both species, dwarfing previous comparisons (Table 1). This comparison returned results consistent with previous studies: homology excluding indels was over 98%; including indels brought it down to 95%. As expected, the 2003 Anzai et al., paper (that found 87% homology including indels in one chromosomal region) was shown to be an inappropriate estimate for the genome as a whole. Beyond its wide impact in the biological sciences, this paper also received much attention from the mainstream media. This work, however, did not make any discernable difference to the RTB model. In 2006, another major RTB book, Creation as Science (CAS), appeared. In contrast to the lengthy, detailed discussion of human / chimpanzee comparative genomics in WWA, CAS has only a brief section as follows:

New research, however, indicates that the widely advertised 98 to 99 percent similarity between human and chimpanzee DNA is greatly exaggerated. Such claims are based on small segments of the human and chimpanzee genomes where common sense dictates that the similarities would be the greatest. While comparisons between the complete human genome and the complete chimpanzee genome have only recently begun, the most complete comparisons performed thus far indicate that the degree of similarity is more like 85 to 90 percent. (p. 156)

The above paragraph from CAS cites four research publications, each of which was previously cited in WWA: Anzai et al., 2003; Thomas et al, 2003; Arnason et al., 1996; and the Chromosome 22 Consortium paper of 2004 (Table 1). Surprisingly, CAS makes no mention of the actual whole-genome study published between WWA and CAS. On encountering this, I initially assumed that Ross and Rana were simply unaware at the time CAS went to press that the chimpanzee genome had been completed, or that perhaps they had mistaken the Anzai paper as a whole-genome analysis. Further investigation, however, failed to support these hypotheses. First, in an article published in 2004 in the RTB periodical Connections, Rana emphasizes that the Anzai paper is not a whole genome comparison and discusses its actual data set in detail:

Though these whole-genome comparisons are not yet possible, scientists are close, and preliminary results indicate that humans and chimpanzees are really not so genetically similar… another study found only 86.7% genetic similarity when segments of human and chimpanzee DNA (totaling 1,870,955 base pairs) were laid side by side.

Thus Rana correctly understands that the Anzai paper is not a whole-genome comparison. Secondly (and more significantly), Rana does mention the key 2005 whole-genome paper in the very first 2006 edition of Connections, and notes correctly that it is a whole-genome study:

Where were you on September 1, 2005? Perhaps you missed the announcement of a scientific breakthrough: the influential journal Nature published the completed sequence of the chimpanzee genome. This remarkable achievement received abundant publicity because it paved the way for biologists to conduct detailed genetic comparisons between humans and chimpanzees.

Rana uses this as an introduction to discuss another article from the same journal issue and does not discuss this key paper or its results, beyond a footnote referring readers to WWA. While this Connections article does not have a precise publication date, Rana cites accession of online material for this article as occurring on November 30, 2005. Other articles in this edition of Connections also cite access dates in late November 2005, suggesting that this volume was drafted in late 2005 for publication early in 2006. The chapter in CAS discussing human / chimpanzee genomics has references to online material cited as accessed in April 2006, indicating that this chapter was still in revision at this time. Taken together, these lines of evidence strongly suggest that RTB was aware of the key 2005 paper at the time the CAS chapter was in preparation, and that they correctly understood its significance as the first whole-genome comparison. The choice of language in CAS also supports this conclusion, since the chapter claims that “… comparisons between the complete human genome and the complete chimpanzee genome have only recently begun…” which makes sense only if both genomes were sequenced at the time of its writing. Despite this concession, CAS makes no mention of the key 2005 paper or its findings, and claims rather that “the most complete comparisons performed thus far” support homology values in the 85-90% range. In reality, only the Anzai paper, which covered a small chromosomal region expected to be disproportionately different between the two species, supports this value (Table 1).

The RTB model and primate genomics (2009): More Than a Theory

The next major RTB publication dealing with human - chimpanzee genomic comparisons was More Than a Theory (MTT) published in 2009. The relevant passage in MTT is a lightly reworked version of what appears in CAS, with only one notable change: whereas CAS acknowledges that comparisons between the completed genomes are underway, MTT claims they have not yet been done (Figure 1).

Like CAS, MTT claims “the most complete analyses performed so far” indicate homology values in the 85-90% range, makes no mention of the key 2005 whole-genome comparison paper, and again cites exactly the same references as CAS, the most recent being the 2004 consortium paper (Table 1). Thus, four years after they were aware of the key 2005 paper, there is still no mention of it to be found in the RTB framework; moreover, MTT claims such an analysis has never been performed.

The RTB model and primate genomics – present day

The pattern we have seen in the major RTB books continues into the present. Rana, for example, continues to argue that the best estimate of whole-genome human chimpanzee homology is at best 90%. For example, during a recent podcast discussion of the completed western clawed frog genome (Xenopus tropicalis) Rana claims: “It’s common parlance that humans and chimps have a 99% genetic similarity. The actual data indicates probably it’s closer to 90% similarity as opposed to 99% similarity” before going on to imply that the higher value can only be supported through comparisons of specific genes. He then goes on to claim that sequenced frog genome shows 80% similarity to the human genome based on “the same reasoning.” The argument he makes is an attempt to cast doubt on the relevance of the human / chimpanzee comparison: if humans and chimps are 90% similar and humans and frogs are 80% similar, Rana claims these “are not meaningful comparisons in a biological sense.” Rana’s argument, however, is deeply flawed in that he is comparing two very different measures of similarity and claiming they are equivalent. The human / chimpanzee value, as we have seen, is 95% genome-wide identity (including indels) for the completed genomes of both species compared across approximately three billion DNA base pairs (Table 1). The 80% value Rana touts for the human / frog comparison, however, is merely a measure of the percentage of genes in the frog genome that have a similar gene in humans implicated in a human disease. It is not even a measure of the genetic similarity of those genes, but merely a fraction of the genes identified in frog that might be useful for studying human diseases. Rana, however, presents these two values as equivalent measures in an attempt to disparage human / chimpanzee genomic similarity. In reality, the genome-wide homology between Xenopus tropicalis and humans is slightly over 30%.

Taken together, these findings demonstrate the following: (a) RTB carefully followed the primary literature on human / chimpanzee comparative genomics up until and including a major paper published in 2004, even if it represented such studies selectively to their constituents; (b) RTB was aware of the key 2005 whole-genome study and correctly understood its implications at the time the first 2006 edition of Connections was drafted in late 2005; (c) RTB has made no mention of this paper (nor any paper in this field published since 2004) in two major works published after this paper was available; (d) RTB continues to claim, five years after this paper was published, that the most recent and most extensive evidence supports their preferred value of 85-90% homology (and that higher values can only be supported with small, biased samples), despite the fact that this conclusion is starkly at odds with the best and most extensive study available, and is itself derived from a comparatively small, biased sample; and (e) RTB has shifted from acknowledging (in 2006) that whole-genome comparisons have been done to denying (in 2009) that they ever have.

In the second part of this series, Dr. Venema will continue his evaluation of the RTB model by examining how it approaches a second powerful line of evidence for human evolution: pseudogenes.

A Response from Dr. Rana: “Creation as Science (2006) was initially published by NavPress and More Than a Theory (2009) was published by Baker as a reworking of Creation as Science. There was an urgency to get More than a Theory to the publisher so that it would be released to coincide with the Darwin Day Celebration. Hugh Ross intended both books to be an overview and summarized material from Who Was Adam? (2005) which was published before the whole genome work on the chimpanzee was published. This explains why the work on the whole chimpanzee genome was not mentioned in More than a Theory. There was nothing done to be deliberately deceptive regarding the failure to mention the work on the whole genome of the chimpanzee.”

Notes

1. For a review of these lines of evidence, see Venema, D.R. (2010). Genesis and the genome: genomics evidence for human – ape common ancestry and ancestral hominid population sizes. Perspectives on Science and Christian Faith 62 (3), 166-178.
2. Ross, Hugh. More Than a Theory: Revealing a Testable Model for Creation. Grand Rapids: Baker Books, 2009, p. 21.
3. Rana, Fazale and Ross, Hugh. Who Was Adam? A Creation Model Approach to the Origin of Man. Colorado Springs: NavPress, 2005, p. 223; Ross, Hugh. Creation as Science: A Testable Model Approach to End the Creation / Evolution Wars. Colorado Springs: NavPress, 2006, p. 156; and More Than a Theory, p. 187-188.


Dennis Venema is professor of biology at Trinity Western University in Langley, British Columbia. He holds a B.Sc. (with Honors) from the University of British Columbia (1996), and received his Ph.D. from the University of British Columbia in 2003. His research is focused on the genetics of pattern formation and signaling using the common fruit fly Drosophila melanogaster as a model organism. Dennis is a gifted thinker and writer on matters of science and faith, but also an award-winning biology teacher—he won the 2008 College Biology Teaching Award from the National Association of Biology Teachers. He and his family enjoy numerous outdoor activities that the Canadian Pacific coast region has to offer. Dennis writes regularly for the BioLogos Forum about the biological evidence for evolution.

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Christopher - #39702

November 13th 2010

RTB’s stance is completely moot, and unnecessary for a modern creationist. I’ll take an alternative approach to the argument to point out why:

Assume that Chimp-Human gene identity was found to be 99.99%. This assumption would be a credible hypothesis given that biological development can be steered by minute changes. So if this was the case, we might say that our proof of evolutionary ancestry is even stronger. However, how does it DISPROVE a completely unique creation of the human from all other organisms?

Creationists seem to make a misguided attempt at trying to disprove an event that cannot be experimented with - they fall prey to their very own antithesis. They want to say that unique human creation cannot be disproved but that evolution can. Rather, both ideas, while not mutually exclusive, are just as well not disprovable.

Could God have created humans separately? Of course! He can just use the same palate of genes. Why does He have to make creatures chemically different to make them ultimately different? The first humans could have lived for eons while the world evolved around them. This can’t be disproved either, because they wouldn’t have left a fossil record.


Paul - #39704

November 13th 2010

Hi Dennis,

Those of us who are not biologists are to a large extent relying on your expertise in accepting your critique of RTB as valid. I’m not particularly a supporter of their organisation, but I do think that Rana deserves credit in other areas. I’ve noticed that he has mentioned in several articles/podcasts, including a very recent one, that he regards irreducible complexity as a poor argument, and one that is well countered by modern scientific research. I don’t doubt that he would have other arguments against evolutionary theory (that may or may not be scientifically supportable), but this to me at least indicates some level of scientific integrity, i.e. he is not willing to just jump on the anti-evolutionary band wagon and accept any and all arguments that can be mustered. However, having said that, I’m pretty convinced that a high percentage of what Hugh Ross has to say on scientific disciplines outside his area of scientific training (astronomy/astrophysics) is inexcusably inaccurate.


BioBill - #42137

December 1st 2010

@ John - #38959

“I think that given the public’s confusion on this issue, in that the average Joe can’t distinguish between humans and chimps “sharing 99% of their genes” (they share 100%, at least to 3 significant digits) and human and chimp coding cDNA sequences being 99% identical, it’ll be easy for RTB to obfuscate on this.”

So true, even my non-scientist brother knows that we “share half of our genes”, cousins share a quarter.

@ conrad
“There may be SOME common ancestry but about 40 thousand years ago human evolution took a leap that was NOT the gradual effect of evolution.
....
What niche in the environment led to the development of chimps that could do calculus?”

It took humans another 39,600 years to do calculus.  That’s pretty gradual.


BioBill - #42138

December 1st 2010

Of course, it was much more than 40,000 years.  I only repeated conrad’s little error to highlight his bigger error.


Peter - #42257

December 2nd 2010

I recently read MTT, and was struck by what seemed to me two clear trends in the book.  One was the willingness of Ross to string out the astrophysics/cosmology threads as long as possible, exaggerating the case by presenting long lists of “facts” and such that were routinely littered with repetition or insignificant differences between entries.  Another was the astounding degree to which he appears to be out of touch with the more recent advances in biology, and specifically genetics, especially as discussed in the article here.  While I don’t necessarily expect a typical astrophysicist to be current in fields closer to my own home stomping grounds (biomedical sciences, with especial interest in mammalian—most particularly human—physiology, cell biology, and genetics), if that same astrophysicist decides to write a book delving into the topic, I expect him to make a proper go of it.  With no disrespect intended, that was not done.

I hold the Bible to be true, but I also hold God’s general revelation as presented in the natural world to be true.  Any apparent conflict arises out of my human misunderstanding or failure to comprehend at all what God has wrought.  Too tight a hold limits my ability to see where I may be wrong.


Trevor K. - #42271

December 2nd 2010

A lot of useless discussion but only if you ignore the essential problem: Disbelief in a straightforward reading of the bible.

For those not inclined to be persuaded by and bow down to modern atheistic science:
http://creation.com/lennox-design-and-suffering


Jim - #44810

December 23rd 2010

First I have read MTT, secondly I have minimal expertise in biology, but please allow me to spew a few thoughts from my sphincter recti. Anyone who has teenagers might expect an even > 95% homology between human and chimp genomes. HGP revealed a humiliating < 25K genes in the human genome (C. elegans ~ 20K) thus insulting our biological complexity, although we can derive some comfort in our ~ 150K unique proteins. However sequence is only DNA’s first language, and biological molecules respond to the 3-D shape of nucleotide motifs rather than reading letter code. Also key are species-specific spliceosomes that aid in generating an array of unique proteins from a smaller set of genes. And there are a number of other subtleties including cellular protein crowding, glycosylation (not under direct DNA control) etc that differentiate species. For those who feel that man is a result of purely evolutionary processes, a higher degree of homology can be interpreted as evidence for this. For those who favour a Creator as the cause of human existence, I’m not really sure that biblical text demands less than 90% similarity between us and our closest primate. But then again, it’s just me spewing.


Jim - #44811

December 23rd 2010

Oops. In the last line I meant to say: I’m not really sure that biblical text demands less than 90% “physical” similarity between us and our closest primate.


Enoch - #47050

January 12th 2011

RTB “believes” scripture is the inspired Word of God and does their best to make sense of the scientific data. Biologos “beileves” in macro-Evolution and does their best to hold on to Christianity without staying true to honest interpretation of scripture.

The purest of Theistic Evolutionists apparently believe that God created a few simple chemicals, and then sat back and watched life unfold by random mutations and natural selection, with no additional input on His part. Some (less pure I suppose) Theistic Evolutionists assert that God is the Grand Guider for the evolutionary process, and is somehow involved, making the process less random. However, this assertion seems to be such a contradiction, because the theory itself states that everything is possible without supernatural intervention. So, on the one hand are the atheistic evolutionists who assert that the whole process works without God, and on the other hand are the theistic evolutionists who subscribe to the exact same details of the evolutionary process as do the atheists, except that they insert God into the equation and say He is the Grand Guider of this random chance method…seems like such a contradiction.


Jon Garvey - #47112

January 13th 2011

@Enoch - #47050

Enoch, you’ve missed out the considerable number of us who hold to a Biblical doctrine of providence, It is those without it, on both sides of the debate, who insist on dividing the world into “things God did” and “things God didn’t do.”

“The lot is cast into the lap, but its every decision is from the Lord.” Meditate on that for a bit, and then answer whether throwing dice is a random process, a miraculous process, sometimes a miraculous process or ... that what we call chance is merely a tool in God’s hands.


Enoch - #47127

January 13th 2011

@Jon Garvey -#47112

Jon; Actually you assumed wrong… I also hold to the doctrine of providence. I believe God sustains and is in control of every atom in the universe (even the rolled dice).  I also agree that God could have used evolution to create if it was His desire. My point is that the scientific data can be interpreted per RTB’s model, and that model can be harmonized much better with scripture. The old and new testament are tied together in so many ways that one has to assume that Jesus and Paul were totally deceived about who Adam was.

Why hold to a theory that has so many problems when there is a much better way to interpret the data. It seems obvious that Macro-evolution will not work given any timescale. There are too many very good arguments against it. And dont forget that Darwin himself was mistaken (according to the doctrine of providence) when he assumed that a good God must not be responsible for the death and suffering in this world (the poor little turtles) and then attempted to explain how things could work without a creator.


tjguy - #47692

January 17th 2011

The study Venema touts about the similarity of the chimp and human genomes is not all that impressive even to secularists it seems.  The results of this study were mixed to say the least. The liberal MSNBC News stated the situation concisely: “Genome comparison reveals many similarities – and crucial differences.” 

Basically, the data were so mixed up that anyone could spin the story almost any way they want to by picking the right data.  In fact, there were so many differences that it is very difficult to honestly claim that millions and millions of base pair substitutions and segmental duplications could have occurred since the time evolutionists assume that humans and chimps went their separate ways.  There was no clear discernible evolutionary trail linking chimps and humans in the data like evolutionists were hoping for.

Plus, this study totally neglected the role of epigenetics.  Genes don’t tell the whole story.  There’s much more to our humanity than just DNA.  Phenotypic difference is not a linear function of genotypic distance.  Mining just the genome for explanations is an exercise in reductionism.

Here’s a detailed creationist response to this issue: http://creationsafaris.com/crev200509.htm#20050901a


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