Natural selection is not the whole of evolution, but it’s still definitely part of it


Ken Ham has been having a grand time redefining evolution. It’s interesting in a twisted kind of way: the anti-evolutionists are now at the point of having to accept natural selection as true, and are simply declaring that sure, natural selection is fine, it’s just not evolution, which we hate.

He’s linking to an article by Georgia Purdom that is a fine example of selective use of information, and represents AiG’s weird stance. It begins with a hypothetical dialog. It’s really weird.

Let’s listen in on a hypothetical conversation between a biblical creationist (C) and an evolutionist (E) as they discuss some recent scientific news headlines:

E: Have you heard about the research findings regarding mouse evolution?

C: Are you referring to the finding of coat color change in beach mice?

E: Yes, isn’t it a wonderful example of evolution in action?

C: No, I think it’s a good example of natural selection in action, which is merely selecting information that already exists.

E: Well, what about antibiotic resistance in bacteria? Don’t you think that’s a good example of evolution occurring right before our eyes?

C: No, you seem to be confusing the terms “evolution” and “natural selection.”

E: But natural selection is the primary mechanism that drives evolution.

C: Natural selection doesn’t drive molecules-to-man evolution; you are giving natural selection a power that it does not have—one that can supposedly add new information to the genome, as molecules-to-man evolution requires. But natural selection simply can’t do that because it works with information that already exists.

You know, that last bit is actually sort of true: natural selection shapes, or selects, the variation that already exists (although, indirectly, natural selection does create new conditions in the environment by changing allele frequencies, and those changing frequencies can create new probabilities for recombination…but I’ll give her a pass on that for now, because it’ll just lead to arguments about defining “creative” vs. “unpredictable”). But evolutionary biologists already know about all that. She’s not saying anything that we’d find surprising.

She goes on, though.

From a creationist perspective natural selection is a process whereby organisms possessing specific characteristics (reflective of their genetic makeup) survive better than others in a given environment or under a given selective pressure (i.e., antibiotic resistance in bacteria). Those with certain characteristics live, and those without them diminish in number or die.

Hey, guess what? That’s what we’d say from an evolutionary perspective, too! Unfortunately, this state of blissful concordance cannot last.

The problem for evolutionists is that natural selection is nondirectional

Nope. That’s not really a problem, because a) selection is directional in the short term, shaping the population towards greater adaptedness to local conditions, and b) we generally don’t believe in any kind of long term directionality. It’s the creationists who believe in a mysterious molecules-to-man kind of pressure.

—should the environment change or the selective pressure be removed, those organisms with previously selected for characteristics are typically less able to deal with the changes and may be selected against because their genetic information has decreased…. Evolution of the molecules-to-man variety, requires directional change. Thus, the term “evolution” cannot be rightly used in the context of describing what natural selection can accomplish.

It is correct to note that selection is largely a conservative force — it prunes out variation from a population. So she is right that if natural selection were the only force operating on the gene pool, the distribution of variants would get smaller and smaller over time.

Gosh. If only there were some other forces acting on populations to produce a constant source of new information that apparently Answers in Genesis has never heard of. If only there were other processes that generated new genetic variants that natural selection could act on…

Surprise! There is! It’s called “mutation”.

No matter what the exact value of the human mutation rate, every single possible point mutation will happen in just a few generations somewhere among the seven billion or so people on Earth. And each individual who lives to the ripe old age of 60 (i.e. youngsters) will have experienced a huge number of somatic mutations.

Let’s also note that we have a large body of phenotypic variation, not all of which is genetic but which is observable, measurable, and quantifiable, and which AiG ignores. We also have deep information about population structure and patterns of inheritance and descent with modification that directly contradicts AiG’s claim that we are descended from a population of two people only 6,000 years ago.

You cannot imagine how stupid Purdom’s article looks to anyone who has some knowledge of genetics and populations, unless you actually know a little bit about those disciplines. She is willfully ignoring a huge part of genetics in order to make a truly idiotic argument.

We’ve all laughed at this clueless quote from fundies.

One of the most basic laws in the universe is the Second Law of Thermodynamics. This states that as time goes by, entropy in an environment will increase. Evolution argues differently against a law that is accepted EVERYWHERE BY EVERYONE. Evolution says that we started out simple, and over time became more complex. That just isn’t possible: UNLESS there is a giant outside source of energy supplying the Earth with huge amounts of energy. If there were such a source, scientists would certainly know about it.

Purdom has basically said the equivalent.

Natural selection reduces genetic variation in a population. Evolution says that we started out simple, and over time became more complex. That just isn’t possible: UNLESS there is a giant source of new mutations supplying the population with huge amounts of variants. If there were such a source, scientists would certainly know about it.

You bet we would.

Comments

  1. Sastra says

    Ironically, what a lot of Young Earth creationists would consider “proof” of evolution would actually be evidence for their ‘hypothesis.’ When asked “what observation would convince you of “macro-evolution?,” they’ll generally give an answer somewhere along the lines of “a dog giving birth to a cat” — or even “a dog turning into a cat.”

    Magic! Poof! Right before your eyes! Yea, Darwin is good indeed.

    It’s what Dawkins calls the “discontinuous mind.” Species have their own separate essences.

  2. slithey tove (twas brillig (stevem)) says

    I see they’ve dropped the simplistic argument that god is just “fine tuning” His first passes. As a way to accept evolution while denying “natural selection” (or vice versa).
    That He is just acting like a tinkerer who cobbles something together to do a particular task, then over time keeps refining it, which we, in hindsight, see as evolution in action.
    They must have had that postulate at some point, right? It is so simplistic, it fits right in to their way of thinking. *shrugs*
    probably easily refuted, so it must have evolved to compensate. /irony

  3. Ogvorbis: I have proven my humanity and can now comment! says

    Now, I realize that I am an historian, not a scientist. So, take this with 64.79891mg of NaCl, but, when I read:

    That just isn’t possible: UNLESS there is a giant source of new mutations supplying the population with huge amounts of variants. If there were such a source, scientists would certainly know about it.

    I have an urge to walk out of my office and look up in the sky. Assuming it is a sunny day (which, in NEPA, is not as often as I would want), I can see the sun. A giant thermonuclear furnace supplying us with heat (which is energy, right?), light (again, that is energy, right?), and other forms of radiation (which, if I remember my high school science classes, is, again, energy). Turn off the sun, remove that outside-the-ecosystem source of energy, and watch how fast everything on earth dies. How fast entropy reasserts itself without an outside energy source.

    There are ecosystems that are not dependent on the energy from the sun. But the thermophiles surrounding the black smokers in the deep ocean also use energy from outside the ecosystem — the radioactive decay going on inside the earth provides lots and lots of heat (which is energy) and the hot water cycling through the cracks pick up minerals which can be broken down to produce energy (wow, energy AGAIN!). Were the sun to cease liberating energy, almost every ecosystem on earth would die fast. Except those thermophiles. They’s have a field day. Without fields, of course.

    Thermophiles must be Gawd’s Chozen Wuns!

    The idiots expounding creationism, in all the myriad guises of the modern milieu, have no clue what entropy actually means.

  4. Ogvorbis: I have proven my humanity and can now comment! says

    And I copied/pasted the wrong paragraph. It should have been:

    That just isn’t possible: UNLESS there is a giant outside source of energy supplying the Earth with huge amounts of energy. If there were such a source, scientists would certainly know about it.

    All hail Tpyos, sand hir accolyte Copypastia!

  5. slithey tove (twas brillig (stevem)) says

    [paraphrase to follow]
    creating more complexity requires adding energy, right, evilushionistas? Where is all this energy coming from, you gots to ask. I then went outside, looked up, and the light hit me! sheesh,

  6. Rob Grigjanis says

    We’ve all laughed at this clueless quote from fundies.

    It’s actually doubly clueless. Apart from apparently forgetting about the sun, it also implies that life generates net negative entropy changes. Any decreases are very local, and more than made up for by the inefficiencies in biological processes.

    I like to use building a cairn as an analogy. When you’re done, the entropy of the system consisting of rocks has decreased. But the entropy of the system consisting of rocks plus builder has actually increased quite a lot. That’s because our large muscles only have an efficiency of about 20%. So the dissipated energy is four times as much as the mechanical energy required to construct the cairn.

  7. raven says

    Evolution says that we started out simple, and over time became more complex. That just isn’t possible:

    Sure it is possible.

    I did it myself. So did you.
    At one time, I was a single cell. Which grew and developed into an adult, walking, talking, typing,…human.
    So did my cat although she doesn’t type. Very well anyway.
    So did you.
    So did all living metazoans on earth.

  8. blf says

    I see they’ve dropped the simplistic argument that god is just “fine tuning” His [sic] first passes.

    Overstatement. No, some seem to being saying that, perhaps, but not all, nor will some cretinist not assert that nonsense in the future. Reading into the OP’s quotes that a line of bullshite is being abandoned is about the same as expecting Why are there still monkeys? to vanish after being explained multiple times.

  9. unclefrogy says

    creationists like most christians have been conditioned by belief so thoroughly that it seems impossible for them to see things as a whole it is so easy for them to just ignore whole “variables”. it is such an isolating perspective.
    uncle frogy

  10. Nullifidian says

    Dr. Georgia Purdom received her PhD in molecular genetics from Ohio State University. Her professional accomplishments include the winning of a variety of honors, research presentations at national conferences, and the completion of six years of teaching at Mt. Vernon Nazarene University (Ohio), where she served as a professor of biology.

    Q. I don’t understand. How the fuck could she be so qualified & also be so fucking ignorant?
    A. The power of wishful thinking &/or indoctrination.

    She’s an idiot.

  11. monad says

    Well, I have long heard creationists dismiss “survival of the fittest” as nothing but a truism. I guess it’s some kind of progress for them to realize that means it has to be, you know, true.

  12. anchor says

    Its rather amazing how allergic to the very notion of ‘evolution’ Ham and his ilk are. Put to it, they must unequivocally deny, for example, so much as that the Sun evolves across the sky as the Earth rotates daily. They must hate the very idea of the passage of time very much. They are so glued to the heavenly ‘ideal’ of eternal stasis that it makes one seriously wonder if people like Ham are capable of noticing any change in the world since they were kids. I think they resist the notion and deny it because it scares the hell out of them: its the way they’ve been brought up, thinking changelessness is compulsory to godly order. Any change (evolution) is automatically branded a sacrilegious flaw in [god’s] scheme of things. Too terrifying to think He presides over a universe that is never, ever, perfectly specified (or even pinned per spec) by the omnipotent. How dare God introduce the agent of all flaw and other evil departures from perfection – time. Perhaps its a trick of the devil.

  13. anchor says

    Perhaps the devil put the Sun in the sky, that enormous source of energy that has the unmitigated gall to shed heat and light on self-respecting planets like ours which would much rather reach thermodynamic equilibrium with the current 2.7 or so degrees K above absolute zero temperature of the universe. How DARE our planet violate the 2nd Law by its exposure to the sunlight and get all agitated. Oh, and horror, drives most of life on it…one might as well attribute this evil of local disequilibrium to the devil.

  14. rietpluim says

    Checking calendar… Yep, it’s still 2016, the clock has not turned back to when creationists first used the “second law” and “no new information” arguments… They haven’t made up anything new in years, have they?