Category Archives: Evolutionary Biology

Has There Been Biological Progress?

 (This article was reprinted in the online magazine of the Institute for Ethics & Emerging Technologies, March 6, 2016.)

We have already seen thinkers like Ray Kurzweil and Hans Moravec defend the idea that cosmic evolution is progressive. But what of biological progress? The debate between those who defend evolutionary progress and those who deny it has been ongoing throughout the history of biology. On the one hand, more recent biological forms seem more advanced, on the other hand no one agrees on precisely what progress is.

Darwin’s view of the matter is summarized nicely by Timothy Shanahan: “while he rejected any notion of evolutionary progress, as determined by a necessary law of progression, he nonetheless accepted evolutionary progress as a contingent consequence of natural selection operating within specified environments.”[i] This fits well with Darwin’s own words:

There has been much discussion whether recent forms are more highly developed than ancient . . . But in one particular sense the more recent forms must, on my theory, be higher than the more ancient; for each new species is formed by having had some advantage in the struggle for life over other and preceding forms I do not doubt that this process of improvement has affected in a marked and sensible manner the organization of the more recent and victorious forms of life, in comparison with the ancient and beaten forms; but I can see no way of testing this sort of progress.[ii]

The most vociferous critic of biological progress was Harvard’s Stephen Jay Gould (1941 – 2002) who thought progress an annoying and non-testable idea that had to be replaced if biological history were to be understood. What we call evolutionary progress is really just a random moving away from something, not an orienting toward anything. Starting from simple beginnings, organisms become more complex but not necessarily better. In Gould’s image, if a drunk man staggers from a wall that forces him to move toward a gutter, he will end up in the gutter. Evolution acts like that wall pushing individuals toward behaviors that are mostly random but statistically predictable. Nothing about it implies progress.

The biologist Richard Dawkins is more sanguine regarding progress, arguing that if we define progress as adaptive fit between organism and environment then evolution is clearly progressive. To see this consider the predator/prey arms race, where positive feedback loops drive evolutionary progress. Dawkins believes in life’s ability to evolve further, in the “evolution of evolvability.” He believes in progressive evolution.

Darwin seemingly reconciled these two views.

… as the forms became complicated, they opened fresh means of adding to their complexity … but yet there is no necessary tendency in the simple animals to become complicated although all perhaps will have done so from the new relations caused by the advancing complexity of others … if we begin with the simpler forms & suppose them to have changed, their very changes tend to give rise to others.[iii]

Simple forms become increasingly complex, thus stimulating the complexity of other forms. This did not happen by necessity and no law need be invoked to drive the process, nonetheless competition between organisms will likely result in progressively complex forms.

There is probably no greater authority on the idea of evolutionary progress than Michael Ruse whose book, Monad to Man: The Concept of Progress in Evolutionary Biology, is the most comprehensive work on the subject. Ruse observes that museums, charts, displays, and books all depict evolution as progressive, and he thinks that the concept of progress will continue to play a major role in evolutionary biology for the following reasons. First, as products of evolution, we are bound to measure it from our own perspective, thus naturally valuing the intelligence that asks philosophical questions. Second, whatever epistemological relativists might think, nearly all practicing scientists strongly believe their theories and models get closer to the truth as science proceeds. From there scientists typically transfer that belief in scientific progress to a belief in organic progress. Finally, Ruse maintains that the kinds of scientists drawn to evolution are those particularly receptive to progressive ideas. Evolution and the idea of progress are intertwined and nearly inseparable.

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[i] Timothy Shanahan, “Evolutionary Progress from Darwin to Dawkins,” http://biophilosophy.ca/Teaching/6740papers/shanahan.pdf
[ii] Charles Darwin, On the Origin of Species by Means of Natural Selection,  or, the Preservation of Favoured races in the Struggle for Life (New York: Cosimo, Inc., 2007), 211.
[iii] Barrett, P., Gautrey, P., Herbert, S., Kohn, D., and Smith, S., Charles Darwin’s Notebooks, 1836-1844 (Ithaca: Cornell University Press, 1987).

A Recap of Cosmic and Biological Evolution

Our universe is 13.8 billion years old; our solar system is 8 billion years old; and the earth is 4.5 billion years old. A timeline on earth from that point on reads like this (and what a testimony to scientific achievement this list is):

  • billion years of simple cells (prokaryotes),
  • 3 billion years of photosynthesis,
  • 2 billion years of complex cells (eukaryotes),
  • 1 billion years of multi-cellular life,
  • 600 million years of simple animals,
  • 550 million years of complex animals,
  • 500 million years of fish and proto-amphibians,
  • 475 million years of land plants,
  • 400 million years of insects and seeds,
  • 360 million years of amphibians,
  • 300 million years of reptiles,
  • 200 million years of mammals,
  • 150 million years of birds,
  • 130 million years of flowers,
  • 65 million years since the dinosaurs died out
  • 40 million years of butterflies and moths
  • 20 million years of giraffes
  • 15 million years of hominids
  • 13 million years since orangutan-hominid split
  • 10 million years since gorilla-hominid split
  • 6 million years since chimpanzee-hominid split
  • 5 million years of Australopithecines
  • million years of Ardipithecus
  • million years of Australopithecus afarensis
  • 5 million years of Homo habilis
  • 8 million years of Homo erectus
  • 2 millions years of Homo antecessor
  • 600 thousand years of Homo heidelbergensis
  • 350 thousand years of Neanderthals
  • 200 thousand years of Anatomically modern humans
  • 160 thousand years of Homo sapiens
  • 50 thousand years since migration to South Asia
  • 40 thousand years since migration to Australia and Europe
  • 15-40 thousand years since migration to Americas
  • 12 thousand years since evolution of light skin in Europeans

Is something happening here? Is there anything we can infer from all this?

Truth and Evolution


“As a rule we disbelieve all the facts and theories for which we have no use.” ~ William James

I rarely reply to a comment of a previous post. One reason is that, as 30 years of being a professor has demonstrated, you rarely change people’s minds. And I am just too old to enter into a polemic. But I may have been misunderstood. So to clarify the position of my previous post, I’ll reply to this comment.

In view of the fact that you mention the germ theory of disease, its interesting to note that Ernst Boris Chain the co-winner of the Nobel prize for his work in refining and perfecting penicillin, which has probably saved over 200 million lives, believed in God and thought Darwinism was no more than a fairy tale.

The reader is correct that there are theistic scientists, a self-evident claim that no rational person would deny. In fact this blog and my recent book document that 7% of the members of the national academy of science members are theists. Of course the evidence also meticulously shows that religious belief declines with educational attainment, among other factors. Of course this doesn’t mean that religious belief is false, but it does suggest that religion is not best defended by appealing to frequency of religious belief among scientists, for religious belief among that cohort is considerably less than in virtually any other group. Other arguments are perhaps better suited to a defense of religion.

As for the fact that an individual scientist rejects the near unanimous opinion of other scientists, this is hardly surprising. There are hundreds of thousands of scientists in USA—more than ten million if you count all those employed with science and engineering degrees—so it is easy to find outliers. You can find a few scientists who believe in bigfoot or alien abductions too. That doesn’t change the fact that evolution has the same scientific status as the theory of gravity or the atom, a claim easily verified at the National Academy of Science website or any of hundreds of legitimate scientific websites listed below. (Obviously this consensus is based on the overwhelming evidence from multiple sciences including: physics, chemistry, biochemistry, genetics, molecular biology, cell biology, population biology, ornithology, herpetology, paleontology, geology, zoology, botany, comparative anatomy, population ecology, anthropology and more.) Anyone who tells you they don’t believe in evolution is either lying or scientifically illiterate. There is no other possibility. Remember too that when you get a new flu shot each year or finish your antibiotics, your implicitly accepting evolution—viruses evolve quickly.

Still it is possible that the outliers are correct. Maybe what goes up doesn’t come back down, perhaps the earth is flat or things don’t change over time—perhaps the gods deceive us about all of this to test our faith. But I wouldn’t bet on it! To trust the outliers is simple confirmation bias, finding cases to confirm what one already believes.

Yet I have no illusions that anything I say will change people’s mind. As the post states “people don’t want to know, they want to believe.” Interestingly, credulity itself has evolutionary origins. We are wired to believe what our parents tell us—it helped us survive—hence we often believe in adulthood what we were told when we were young.

For those interested in the truth about the fact of evolution you can visit any of these  websites.

I’m sure you could find many others … if you are really interested in the truth.