David Lack: Evolutionary Biologist and Devout Christian

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August 7, 2012 Tags: Lives of Faith

Today's entry was written by Thomas Burnett. You can read more about what we believe here.

David Lack: Evolutionary Biologist and Devout Christian
David Lack reading with his daughter, Catherine, about 1965. Image by Ramsay and Mispratt, Oxford, in the journal Ibis, 1973.

Note: A source of great confusion, hostility, and fear, evolutionary theory gets people all riled up. Some see evolution as a challenge to their faith in God; others find comfort in evolution as an alternative to traditional religion. But there is one facet in which these warring parties generally agree—evolution implies atheism. This interpretation is powerful, unambiguous, and one that many in our contemporary society, both liberal and conservative, have learned to embrace. But despite our culture's efforts to equate evolution with atheism, it simply isn’t true. BioLogos is working to correct this cultural bias, and today we will examine one scientist who completely confounds this common but erroneous assumption about evolution and Christian belief.

David Lack

In my previous essay, I discussed “Darwin’s finches” and how surprisingly little Charles Darwin himself had to say about them. In fact, it was actually the British ornithologist David Lack (1910-1973) who conducted the critical research that immortalized the finches in biology textbooks and popular lore. In 1973, the eminent German zoologist Ernst Mayr wrote:

Already well known among professional ornithologists, his work on the Galapagos finches gave David Lack world fame… There is no modern textbook of zoology, evolution or ecology which does not include an account of his work.1

Ernst W. Mayr
Ernst W. Mayr

Decades have passed since Mayr wrote these words, and David Lack’s name has largely faded from public discourse. On the other hand, the Galapagos finches have become one of the most recognized symbols of evolution in the world today. Does it really matter whether Lack or Darwin gets credit for describing the evolution of these remarkable birds?

Insofar as evolutionary theory contrasted with religious belief, it makes a big difference. In a culture that is eager to equate evolution with atheism, it should come as no surprise that these birds are only known as “Darwin’s finches”. Darwin’s personal struggles and ultimate rejection of Christianity are well documented, and people are eager to link his loss of faith to his evolutionary theory. David Lack, on the other hand, began his scientific career as an agnostic, but shortly after publishing his famous book on the evolution of Galápagos finches, he converted to Christianity! 2

A Christian at the forefront of evolutionary biology

Lack’s Christian conversion did not mark the end of his scientific achievements, either. In fact, he continued as a prolific researcher until just weeks before he died. Among his many achievements, he was Director of the Edward Grey Institute of Field Ornithology (1945-1973), Fellow of the Royal Society, and President of both the International Ornithological Congress (1962-66) and the British Ecological Society (1964-65). His fellow scientists held him in great esteem:

He was described as one of the most outstanding among world ornithologists; he was certainly this, but he was also one of the world’s leading evolutionists. All the time one saw developing his use of birds as material for the study of wider, deeper, biological problems.3

David Lack in search of Chimney Swifts
David Lack at the International Ornithological Congress, 1962.

Clearly David Lack was an outstanding scientist, and his commitment to Christianity did not tarnish, hinder, or undermine his research on evolution. But we might also ask, what was Lack like as a Christian? Did he keep his faith hidden from view, afraid that it might compromise his reputation as a scientist? Ernst Mayr, who interacted with David Lack professionally and personally for nearly 40 years, had this to say:

I have known only few people with such deep moral convictions as David Lack. He applied very high standards to his own work and was not inclined to condone shoddiness, superficiality and lack of sincerity in others. This did not always go well with those who preferred to compromise in favour of temporary expediency. David had been raised in an environment in which great stress was layed on moral principles and this attitude was later reinforced by his Christian faith. This explains his extraordinary unselfishness and modesty, and his great devotion to his family, to his students, to his friends, and to all the things that he lived for. The equanimity, indeed serenity, with which he faced death after his terminal cancer had been diagnosed is further evidence of the strength which his faith gave him.4

Like Asa Gray5 before him, and Francis Collins6 after, David Lack was an sincere, devout Christian, as well as a leading scientist who employed evolutionary theory to make brilliant discoveries about the natural world. Though Lack did not see any conflict between his scientific and Christian beliefs, he was sympathetic to the concerns of his fellow Christians. Therefore, ten years after publishing his masterpiece on Darwin’s Finches, Lack wrote another book entitled Evolutionary Theory and Christian Belief: The Unresolved Conflict.

Originally published in 1957, this book deals with the very same science and faith questions that Christians struggle with today— topics like randomness and chance, death in nature, miracles, and evolutionary ethics. While it would be unreasonable to expect anyone to completely resolve these matters, Lack offered numerous insights both as a devout Christian and one of the world’s leading biologists.

Let’s take a brief look at how Lack addressed some of these questions.

Blind Chance or Divine Plan?

Evolutionary theory does not invoke supernatural forces in explaining the history of life on Earth; instead, it relies on naturally-occurring processes to account for the vast diversity of life. Additionally, it explains animal behavior largely in terms of survival and reproduction, without appealing to any higher purpose of life. Taken together, does this imply that God is absent, and that our lives are ultimately meaningless?

David Lack responded,

Behind the criticism that Darwinism means that evolution is either random or rigidly determined lies the fear that evolution proceeds blindly, and not in accordance with a divine plan. This is another problem that really lies outside the terms of reference of biology. It is true that biologists have inferred that, because evolution occurs by natural selection, there is no divine plan; but they are being as illogical as those theologians whom they rightly criticize for inferring that, because there is a divine plan, evolution cannot be the result of natural selection.7

When rendering judgment on the ultimate meaning of life, biologists are speaking from their person beliefs, not from scientific authority. Moreover, Lack pointed out that many science enthusiasts have employed the concept of “randomness” in ambiguous and misleading ways:

Mutations are random in relation to the needs of the animal, but natural selection is not. Selection, as the word implies, is the reverse of chance.8

In support of his view, Lack pointed out that convergent evolution has produced uncanny resemblances between distantly-related species across the world, notably among marsupials in Australia. Different evolutionary trajectories can lead to very similar results.9

Death in Nature

After addressing concerns about the seeming “randomness” of evolution, Lack turned to another great concern, the role of death in natural selection:

Various writers–some Christian and others agnostic–have been troubled about natural selection not only because it seems too random, but also because it is so unpleasant.10

Image courtesy John Marsh Photography via Flikr

Genetic mutations are generally harmful, and for evolution by natural selection to produce new forms of life, an awful lot of organisms must die. For many Christians, it is inconceivable that a loving and merciful God would allow death on such a vast scale.

But Lack also pointed out that rejecting evolutionary theory doesn’t actually get rid of the problem of death. Regardless of what we think about evolution, the brute fact of mass extinction remains. Fossils of innumerable animals, plants, and microorganisms clearly demonstrate that the vast majority of species that have ever lived are now dead. It may be quite troubling for us to observe that our planet is a giant graveyard of natural history, but rejecting evolution will not change this fact.

Some Christians conclude that death could not have been part of the divine plan; instead, it must be the work of the devil, or the result of human sin. But this interpretation contains an implicit assumption that death is always evil. Is this really true? David Lack offered two intriguing insights:

See more on death and the Fall.

Blue-cheeked Bee-eater (Merops persicus) pair in
courtship, seen in Basai, Gurgaon, India.
Image courtesy Koshy Koshy.

  1. For a population to maintain a stable size, all births must be balanced by a corresponding number of deaths. A world in which no animals die is a world in which no animals are born. That means no reproduction, no courtship, and by implication, no singing birds—much to the dismay of ornithologists and people in love!


  2. Some people, taking cues from Isaiah 11:6-7, suppose that in a perfect world, animals only eat plants. But in fact, plants themselves depend on the bacterial decay of dead organisms. If animals didn't die, then essential nutrients would disappear from the ground, and plants could not continue to grow. Eventually, there would be nothing left for animals to eat, and all life would cease.11


Many Christians are uncomfortable with evolutionary theory because it denies a miraculous, supernatural origin of life. They fear that if those miracles are denied, it might lead people to reject the possibility of miracles altogether, including the central feature of the Christian faith—the resurrection of Jesus from the dead.

As a devout Christian, David Lack certainly affirmed the fundamental tenets of the gospel. But at the same time, he explained to his readers that invoking miracles to account for unusual features of the natural world is not particularly helpful when trying to deepen our understanding of God’s great multitude of creatures:

[The biologist's] research depends on repeated observations. It need not, as popularly supposed, consist solely, or even mainly of measurements and experiments, but unless events are repeated, they cannot be assessed by science. Hence truly unique events come outside the domain of science, though biologists are not usually convinced when told they must, therefore, leave such problems as miracles to others. For one of the chief ways in which research has advanced is through the discovery of apparent exceptions to the known rules, and if further study shows the exceptions to be replicable, new regularities are revealed from which modified rules can be propounded. This method has been so successful that the biologist tends to doubt whether there are any types of irregularity, or seeming irregularity, that will not yield to it.12

But just because a scientist cannot repeat a particular event doesn’t mean it didn’t happen. Both natural history and human history contain unique events that only happened once. As we peer into the past, the difficulty of discerning fact from fiction inspires us to further investigate the mysteries that surround us.


David Lack’s book Evolutionary Theory and Christian Belief was quite insightful, but his enduring achievements took place in evolutionary biology, a place where many Christians are afraid to tread. While it is significant that he himself found no contradiction between his faith and his science, perhaps the greatest testament to the compatibility between Christian faith and evolution is the life he led as a believer in both. As we saw in Ernst Mayr’s candid praise, Lack reflected the light of Christ through both his personal and his professional relationships.

Today, many voices in our culture still insist that evolution is incompatible with a sincere faith in Jesus, but a careful look at history demonstrates otherwise. In the future, perhaps more people of faith will have confidence to study biology knowing that one of the most iconic symbols of evolution—the Galapagos finches—owe their fame in large part to a devout Christian named David Lack.


1. Mayr (1973) “David L. Lack.” Ibis: 433.
2. Larson, E. J. Evolution's Workshop: God and Science on the Galapagos Islands. New York, Basic Books, 2001: 218. See also Lack, David. (1973) “My life as an amateur ornithologist.” Ibis: 431.
3. Alister C. Hardy (1973). "David L. Lack." Ibis: 436.
4. Mayr (1973) “David L. Lack.” Ibis: 433.
5. For more about Asa Gray, see the BioLogos FAQ “How have Christians responded to Darwin’s Origin of Species?
6. See Francis Collins’ autobiography The Language of God: A Scientist Presents Evidence for his Belief (New York: Free Press, 2007) (book info)
7. Lack, David. Evolutionary Theory and Christian Belief: The Unresolved Conflict. Methuen & Co., 1957: 67.
8. Lack, p65.
9. For more on convergent evolution and the possibility that evolution could be compatible with some form of divine purpose, see the work of Simon Conway Morris, especially The Deep Structure of Biology: Is Convergence Sufficiently Ubiquitous to Give a Directional Signal? Templeton Press, 2008.
10. Lack, p72.
11. Lack, pp75-76.
12. Lack, p82.


Thomas is a former BioLogos Associate Editor. As a science writer, he has also worked for the American Scientific Affiliation, National Academy of Sciences, and the American Association for the Advancement of Science. He has degrees in philosophy and the history of science from Rice University and University of California, Berkeley.

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Jon Garvey - #71746

August 7th 2012

Just one small point of interest (to me).

“Genetic mutations are generally harmful”. Not put in quotations from Lack, but part of the received wisdom of his age, and underlies much of the theodical argument for rejection of God’s oversight of evolution: for every beneficial change, thousands of dead misfits

But was not most of the early research on mutation done through ionising radiation, and productive of the monstrosities beloved of sci-fi stories like the Incredible Hulk? That was one reason that for some time mutation was downplayed as a mechanism of evolution.

But since Kimura, has it not been shown that the vast majority of mutations are near-neutral? Occasionaly harmful, occasionally helpful seems to be what actually happens in nature, rather than at Hiroshima. That poses some problems for adaptive natural selection, but even more for the “pile of corpses” view of mutation.

Whatever the mechanisms of nature, most offspring survive, so maybe that argument against the “theistic” part of evolution should be laid to rest as a harmful mutation.

Thomas Burnett - #71763

August 7th 2012

Excellent point, John!  If you can suggest some well-written articles explore the ratio of beneficial/neutral/harmful mutations, I bet many of our BioLogos readers would be very interested.

Jon Garvey - #71765

August 7th 2012

Beyond my pay scale as a retired doctor, Thomas! There should be some population geneticists hiding in the woodwork with the information to hand!

However there’s a link to a useful 2009 overview by Eugene Koonin of current evolutionary trends including reference to neutral theory here which may be a start.

Roger A. Sawtelle - #71783

August 8th 2012


Thank you for the articles by Koonin.  It was most interesting, thorough, and enlightening.

For me it amply demonstrates that evolutionary biology today is all about the genetic aspect, which focuses on how genes and genomes change or about variation, as opposed to natural selection which is the other half of the Darwinian dynamic of change and development.   

Jon Garvey - #71784

August 8th 2012

Does it work, though, Roger? Koonin is the same guy who’s suggested invoking the many-worlds multiverse to bring the odds for DNA replication evolving into manageable numbers.

The more selection is sidelined, the more the quasi-intelligent substitute for Darwin’s human breeders fades from view, and the closer one gets to “interesting stuff just happens.” Sometimes it looks as though natural selection gets roped in again at certain phases of evolution just to save the day.

Roger A. Sawtelle - #71791

August 8th 2012


As I read the article, natural selection is not required for “neutral” genetic drift which does not change the relationship between the organism and its environment.  This then is not evolution, although change in the genetic makeup can produce different species who are sexually incapatiable.

Any change in the phenotype which does indicate evolution is subject to Natural Selection, which is not genetic, but ecological in my understanding, and thus goes beyond biology and beyond where evolutionary biologists are prepared to go.         

I agree it is a problem because evolutionists do not want to look beyond genetics for answers except for the multiverse Black Box or Deus ex machine.

Gregory - #71752

August 7th 2012

“the greatest testament to the compatibility between Christian faith and evolution is the life he led as a believer in both” - Thomas Burnett

I had thought it was common parlance to say one ‘accepts’ evolutionary theory, rather than ‘believing’ in it, no?

“he was also one of the world’s leading evolutionists.” - Alistair Hardy

If my advice from part I of this series makes sense, then calling Lack an ‘evolutionist,’ i.e. an ideologue for ‘evolutionism’ is misleading. It doesn’t appear to do justice to this Christian who accepted certain knowledge in the field of evolutionary biology as the best explanation of the available evidence in nature. Calling Lack an ‘evolutionist’ suggests an alternative ideological meaning to his scientific ‘evolutionary biology’ (even if Hardy didn’t realise it).

Most biologists still today are not trained in philosophy of science and thus have a difficult time speaking plainly about ideology and science; evolution = not ideology, evolutionism/evolutionist = ideology/ideologue.

Thomas Burnett - #71766

August 7th 2012

Gregory, I’m glad that you pointed that out.  The relationship between “believing” the gospel and “believing” evolutionary theory is not strictly parallel.

Regarding Alistair Hardy’s quote—“he was also one of the world’s leading evolutionists”—he simply meant that Lack was one of the world’s leading evolutionary biologists.  He was complimenting Lack for being a leader not only in his specialized field of ornithology, but in biology as a whole.

Gregory - #71830

August 10th 2012

You’re welcome again, Thomas. I’d be pleased to see your activity in other threads too, as time permits. My time is short for contribution here also.

You wrote: “Regarding Alistair Hardy’s quote—“he was also one of the world’s leading evolutionists”—he simply meant that Lack was one of the world’s leading evolutionary biologists.  He was complimenting Lack for being a leader not only in his specialized field of ornithology, but in biology as a whole.”

Is there no difference in your view between being an ‘evolutionist’ and an ‘evolutionary biologist’? If not, then the point is mute. If so, then Hardy was wrong to conflate the two terms regarding Lack.

Complimenting Lack is surely not problematic. Calling him something he isn’t or something that it is not appropriate to call him, however, is wrong.

Was David Lack an ideologue for evolutionism or not?

Roger A. Sawtelle - #71754

August 7th 2012


Maybe you can help me here.  I heard someplace that most pregnancies do not come to term.  I do not know if this is true, but a suspect that there are a significant number of miscarriages and stillborns.  If we include those who have other problems from birth like cerebral palsy then we see that birth is indeed something to cherish, rather than take for granted. 

I don’t know if you can count these as mutations, but it is clear to me that the formation of a human being in the womb is not a simple or easy thing.  Maybe it is natural and good for human beings to desire to have sucessful pregnancies and produce “perfect” children, but we are still mortal physical beings.

I suspect that most radical mutations do not reach term or die shortly after birth.  Non-radical mutations lead basically normal lives, but have marginal advantages or disadvantages.  It is just a part of life where people are different, but their lives are determined primarily by how they use the gifts God gave them, rather than the gifts themselves.            

Jon Garvey - #71756

August 7th 2012

Hi Roger…

Thank goodness! When I first saw your response on the e-mail feed I thought it would be from one of those people who say: “most fetuses don’t reach term, ergo either abortion is OK or God is an abortionist.” That’s a similarly dubious argument to the attacks on God from mutation.

When I was practising I was always suspicious of the very variable figures people gave for unseen miscarriages - it’s very hard to assess accurately, and even harder to attribute to causes. What is undeniable is that, in western society at least, maybe 1:4 known pregnancies miscarries, so it’s a genuine theodical issue.

However, I’m pretty sure that the vast majority of fetuses that spontaneously abort, though they do so because of either fetal or placental abnormality, don’t do so because of mutation. Causes could often be chromosomal or genetic (recessive genes etc - that comes under population genetics as Melanogaster would tell you!), but also maybe environmental problems via epigenetics or other developmental problems. But not mainly mutation as such.

It does seem that miscarriage is a natural weeding-out mechanism for such abnormalities - and interestingly enough there isn’t a higher abnormality rate amongst babes who come to term after threatened miscarriage, so it seems to work when the body uses it.

So I wasn’t thinking about those living with large or marginal disability, important though that is medically and theologically in terms of your absolutely correct last paragraph. My point was that most mutation just causes allelic variation of marginal importance, and the world is somewhat less “red in tooth and claw” than the old “most mutations harmful” story suggests.

Does that answer?

Roger A. Sawtelle - #71771

August 7th 2012


Thank you for the information and your thoughts.

It seems that God given reality is always more complex than people want to admit.

There are no easy or simple answers and that is why we need faith to deal with the complexities and ambiguities of life. 

Ideologues on all sides who claim simple answers make problems much more difficult to address as we find in this process.   

wesseldawn - #71860

August 12th 2012

Or it could be simply that the earth is still cursed (”cursed is the ground for thy sake” Gen. 3:17) and the reason why awful things happen here.

The following is an example of just how bad things can get for some people (the picture quality isn’t that great but you can clearly see that this is a human being and no doubt a female because of the head scarf, though her bottom half is turned backwards):



Roger A. Sawtelle - #71885

August 14th 2012


Please stop misinterpreting and abusing the Bible.

Get help.

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