Which Evolution Debate Will Soon Be History?

Post Author: Bill Pratt

In a recent USA Today article, the headline read “Scientist: Evolution debate will soon be history.”  The first line of the article is, “Noted paleoanthropologist Richard Leakey predicts skepticism over evolution will soon be history.”  What do we make of this article?

The first thought that should come to your mind when you read this headline is the following: “Which definition of evolution is Leakey using?”  As I pointed out in a blog post a few weeks ago, there are at least 6 definitions of evolution that are commonly employed.

Unfortunately, you have to read about 10 paragraphs before getting to the answer, and even here the reporter barely covers it.  Perhaps this is because Leakey failed to provide a definition, or maybe the reporter saw no need to clearly define the term (both of these are problematic since the whole article is talking about the evolution debate ending).

So which definition of evolution is it?  Here is Leakey, quoted in the article:

If you don’t like the word evolution, I don’t care what you call it, but life has changed.  You can lay out all the fossils that have been collected and establish lineages that even a fool could work up.  So the question is why, how does this happen? It’s not covered by Genesis. There’s no explanation for this change going back 500 million years in any book I’ve read from the lips of any God.

The best I can tell is that we’re talking about definition 3 from the previous blog post: limited common descent: the idea that particular groups of organisms have descended from a common ancestor.  It is possible Leakey is referring to other definitions, but he never makes himself clear, and so we are left to guess.  He makes no mention of natural selection, universal common descent, or genetic mutations.

If Leakey is referring to limited common descent, then there is no debate at all, and he is arguing against imaginary skeptics.  Virtually every creationist accepts limited common descent.

If, however, Leakey is specifically talking about human evolution (since that is what he is an expert in), then there are several different takes from the creationist community.

Theistic evolutionists would have no problem saying that hominid (pre-human) fossils represent human ancestors.  For them, God placed a soul in the first modern humans, but planned for the process of evolution to provide the bodies.

For old earth creationists, the pre-human hominids were created by divine special creation hundreds of thousands, and even millions, of years ago.  They deny a direct evolutionary link between these hominids and modern humans.

For young earth creationists, hominid fossils represent either extinct offshoots of humans, or extinct apes, these two groups not being evolutionarily related.  Remember that for them, God specially created all major kinds of animals recently in the earth’s history (6,000 to 20,000 years ago).  Since that time, animal life has been rapidly evolving.  Therefore, there is a direct evolutionary link between some of the hominid fossils and humans (such as Neanderthal), but there is no direct evolutionary link between the ape-like hominids and humans.

Those in the intelligent design community may fall into any of these three groups, or they may have even other interpretations of the hominid fossil data.

The point of all this is that there are numerous definitions of evolution and there are numerous views about human evolution.  Before any debate about evolution can end, there is going to have to be a clear definition of terms and then strong evidence marshaled.  This article fails to do either.

As a footnote, Leakey says his reason for wanting the evolution debate to end is the following:

If you get to the stage where you can persuade people on the evidence, that it’s solid, that we are all African, that color is superficial, that stages of development of culture are all interactive, then I think we have a chance of a world that will respond better to global challenges.

What is truly bizarre about this statement is that I’m not aware of anyone from the creationist community who denies any of this.  Certainly Christian creationists have no problem affirming that all humans are descended from the same place, and would even go one further and say that we are descended from the same two people.  We would also affirm that all human races are equal in the eyes of God, and nobody disputes that development of culture is interactive.  I have no idea who Leakey is arguing against in these remarks, and so the main thrust of Leakey’s thoughts are completely lost on me.

  • Sorry to be a stick in the mud here, Bill, but there are not six definitions you listed in the previous post ‘commonly used’ if we are going to talk about evolution as it is properly used in the biological sciences. There is really just one, expressed in various ways, namely, a natural process that results in heritable changes in a population spread over many generations. In scientific terms, this is ‘commonly’ expressed as any change in the frequency of alleles within a gene pool from one generation to the next. That’s it. That’s the sum total.

    Evolution as a fact means natural selection is operant (which is why vaccinations work, for example); evolution as a theory holds the mechanism to be natural selection (which explains why its products are anything but random). These other definitions introduced to us by Intelligent Design and creationist proponents from your previous post are by no means ‘common’ in any scientific discussion about biology… although I have no doubt they are bandied about by people who don’t appreciate the notion that we have a perfectly good natural process that requires no role for an interventionist designing agency. These people are legion and what they are talking about is their preferred notion of some kind of limited heritable changes to make room for some guided agency. This is not evolution but some of perversion of the scientific term, usually altered by some additional and contrary word – like ‘theistic’ or ‘limited’ modifier. These modifiers alter evolution by natural selection to be something else, something other than evolution by natural selection, and none of these ‘something else’ keeps the central tenet in place; all these something else’ definitions stand contrary to the very mechanism that makes evolution operant, namely, heritable changes over time through the mechanism of natural selection, a process as unguided as erosion, as gravity, as germs, as chemical bonding. Any definition that does not adhere strictly to this notion of ‘natural’ meaning unguided by any agency is not evolution by natural selection but some anti-scientific hybrid aimed squarely at perverting evolution to something other than biological science.

    This understanding of evolution by natural selection is not compatible with any sense of creationism with the sole exception of a deistic initiator who then packs up and disappears. There remains not one jot of evidence for any guiding agency in the scientific terms of evolutionary biology. Not. One. Jot. Adding modifiers to alter the definition of evolution by natural selection to suit some other agenda is not science.

  • Andrew Ryan

    I don’t get the relevance of the ‘six definitions’ meme. It’s like taking an article about whether aliens exist, and pointing out ”alien” can also refer to a foreigner living in this country or simply anything that’s a bit unusual or different. So what?

  • Andrew Ryan

    If every Creationist accepts limited common descent, why is ‘where are the transitional fossils?’ such a common Creationist cannard? I’ve seen it voiced countless times by Christian posters on this very blog, and I’ve never seen the question countered by another Christian here, including you, Bill.

  • The key is in the term limited. Every creationist affirms that all the different kinds of dogs are related through common descent, that all the different kinds of apes are related through common descent. It is clear from artificial breeding experiments that animals have a range of morphological variability built into them. Where some would draw the line is saying that apes and dogs have a common ancestor.

    My point is that old earth and young earth creationists have no problem with limited common descent; they just reject that all plants and animals can be traced back to one or a few distant ancestors.

    When creationists decry a lack of transitional fossils, they are talking about transitions between animal groups with major morphological differences. An easy example is the transition from land mammals to sea mammals. The standard evolutionary story is that land mammals evolved first, and then later on some of the land mammals evolved into sea mammals. The question that we ask is: how did this happen? Where are the transitional fossils that clearly lay out how this massive metamorphosis occurred? Nobody disputes that there are transitional fossils between closely related groups of animals.

  • The relevance is that people debating evolution are often talking past each other because they are not getting clear on their definition of evolution.

  • Andrew Ryan

    How do you know what all creationists mean when they talk about trans fossils? Are you saying none deny that any kind of speciation can occur?

  • Andrew Ryan

    The biological definition is the only one that matters. It’s not biologists fault if others make up their own definitions.

  • What do you mean by speciation?

  • Andrew Ryan

    Whatever you want Bill, such that you feel confident in claiming no Crastionist denies it happens.

    Logically, for you to ask me what definition I mean, there must be at least ONE definition that you believe ALL Creationists accepts really happens. . Otherwise you wouldn’t need to know what definition I meant before you answered – you’d just be able to answer: “No, I don’t claim no Creationist drnies speciation.”

    So, what definition of Speciation is accepted by all or virtually all Creationists as being a description of an actual process, either present or in the past.

  • How do creationists explain the human DNA evidence for some ~90,000 simian retroviruses if we share no common ancestry? What, god simply put them there to fool us into thinking we are biologically related?

  • Andrew Ryan

    Can you name any ‘closely related groups’ that you think all creationists are happy to say shared a common ancestor? I’m assuming you don’t just mean different breeds of dog. Are you saying that no Creationist denies that, say lions and domestic cats evolved from the same distant ancestor, or that the fossil record we have for the horse is as scientists claim it to be? If so, I assure you I’ve spoken to Christians on boards like yours who deny just such ideas.

    Are you holding that when we hear ‘where are the trans fossils’, it’s only ever in reference to, say a fish to land mammal transitional fossil?

  • Defining what a species is, is notoriously tricky, so I was just wondering what you thought. In any case, a standard definition I’ve seen is that you have two species if they do not reproduce with each other. In that case, every creationist (young earth, old earth, theistic evolutionist) I know of would affirm that speciation occurs. There are documented cases of single species becoming two species.

  • Ken

    If there’s no need for a guided agency then after decades of trying why have scientists been unable to create life from non-living matter, without manipulation, to explain the origin of life (i.e. abiogenesis)?

  • Why would one expect this could be achieved in this timeframe? It took billions of years to happen naturally!