Wednesday, March 16, 2016

Nonadaptive order: a problem for Darwinism?

http://www.evolutionnews.org/2016/03/a_nightmarish_s102692.html

Stump your Darwinist friends by asking them to explain, in evolutionarily adaptive terms, biological features like the precise pattern of the maple leaf or of an angiosperm flower. "That's a fantastically serious challenge to Darwinism," says Discovery Institute biologist Michael Denton in this brief but delightful video conversation -- a "nightmarish scenario." Why? Because Darwinism by definition must justify such features, including the taxa-defining novelties, as having been seized upon by natural selection because they were adaptive. I mean, that pattern specifically and not some other.
It's the specificity that's the problem. This is a deep point by Denton. For classic evolutionary theory, the curse of non-adaptive order resides in the fact that non-adaptive patterns -- beautiful and complex ones -- absolutely pervade life. An aesthetic choice might explain the act of selection. But blind, dumb natural selection, focused like a laser beam on fitness, carefully designing these thing to be just as they are and no other way? Sorry, that doesn't fly.

27 comments:

John Moore said...

Denton's key assumption is that "Darwinism by definition must justify such features," This is simply false. There's a lot more going on in evolution than just natural selection.

If you want to know more, you could try this recent piece on Pharyngula, although I guess it takes a brave Christian soul to trespass over there.

Angra Mainyu said...

Before stumping one's friends, I would suggest at least roughly studying some of the basics tenets of current evolutionary theory. One suggestion: http://www.talkorigins.org/
Granted, someone might say that "Darwinism" refers only to Darwin's original theory - without any later discoveries and/or changes, improvements, etc. - and then argue against that theory only. But that would be silly at best.

Victor Reppert said...

The rebuttal seems to employ the concept of genetic drift.

Genetic drift — along with natural selection, mutation, and migration — is one of the basic mechanisms of evolution.

In each generation, some individuals may, just by chance, leave behind a few more descendents (and genes, of course!) than other individuals. The genes of the next generation will be the genes of the "lucky" individuals, not necessarily the healthier or "better" individuals. That, in a nutshell, is genetic drift. It happens to ALL populations — there's no avoiding the vagaries of chance.

http://evolution.berkeley.edu/evolibrary/article/evo_24

Genetic drift affects the genetic makeup of the population but, unlike natural selection, through an entirely random process. So although genetic drift is a mechanism of evolution, it doesn't work to produce adaptations.

Cal Metzger said...

VR: "Stump your Darwinist friends by asking them to explain, in evolutionarily adaptive terms, biological features like the precise pattern of the maple leaf or of an angiosperm flower."

If you think this should stump someone who has a basic understanding of evolutionary theory, the only ignorance on display is your own.

Why is a maple leaf shape that shape? Because the mutations that led to that shape proved more advantageous, for those maple trees with the gene for that shaped leaf, than the alternatives among maple tress whose genes resulted in leaves of a different shape (along with any other genetic effects that might be related to that gene).

Why would anyone think that question is a "stumper?"

William said...

Cal,

Please see Victor's note above. Some genetic changes in a population over time do not directly reflect recent selection pressure. Rather, they are a consequence of ongoing genetic fluctuations, and this tendency to fluctuations was in the past selected for by past selection trends, which selected for a population's ongoing CAPABILITY for genetic selection and thus adaptation. It's sort of a evolutionary idling or drifting in the current, as it were :).

So the maple leaf is that shape because it is more advantageous than, say, a barrel cactus thick type shape in that environment, but it's also likely that other shapes (also green, thin, vascular, and flat) could have been equally advantageous, and things just drifted in that direction (genetically and epigenetically) for the maples.

A lot of the individual differences in species are not easily explained by Darwin's theory alone, but can be explained by drift, which is itself explained by modern genetics. The two (selection pressure and drift) reasons for speciation are usually understood to work together these days though.

Gyan said...

Modern theist philosophers are equally at loss regarding the animate world. They divide the phenomena into physical and mental, thereby lumping the non-human life into the realm of purely physical. Thus, for modern theists philosophers, as for atheists, animal life obeys the laws of necessity. And thus, an animal is nothing but a complex machine.

This contrasts with the medieval philosophers for whom there were three distinct realms
1) Inanimate that move by necessity
2) Animate that move by instinct
3) Rational that move by deliberation.

Victor Reppert said...

I still wonder if, even when drift is taken into consideration, a preference in nature in favor of aesthetic beauty wouldn't be evidence in favor of design. Still, it is a little disappointing that DI's argument doesn't really take a full account of modern evolutionary theory into consideration.

I think the ID movement raises important and valuable questions about evolutionary theory that should not be suppressed. I don't think they're just IDiots. But I think they haven't always gone about it the best way.

Ilíon said...

VR: "Still, it is a little disappointing that DI's argument doesn't really take a full account of modern evolutionary theory into consideration."

To be fair to the ID, there *is* no such thing as 'modern evolutionary theory' for the ID even to take into account.

Another thing, which is rather amusing, the very term modern evolutionary theory is something *I* made up, over a decade ago on the ARN discussion boards, to *mock* the pretentions of Darwinism. 'Modern evolutionary theory' is like the 'Holy Roman Empire' -- it isn't remotely modern, it isn't particularly evolutionary, and there isn't even a theory in it.

At some point about the time I grew bored with the goings-on at ARN, the Darwinists there decided that Darwinism needed a new name ... and by consensus, they settled on 'modern evolutionary theory' ... even knowing that and anti-Darwinist had invented the term to mock their pretentions.

Ilíon said...

... obviously, in both cases where I wrote "the ID", I meant "the DI"

Edgestow said...

and by consensus, they settled on 'modern evolutionary theory' ... even knowing that an anti-Darwinist had invented the term to mock their pretentions

Rather like how proponents of the Standard Cosmological Model eventually adopted the term "Big Bang" despite its having been coined by Fred Hoyle, at the time an outspoken critic of the theory. He called it the Big Bang as an insult.

Ilíon said...

me: "To be fair to the [DI], there *is* no such thing as 'modern evolutionary theory' for the [DI] even to take into account.
...
'Modern evolutionary theory' is like the 'Holy Roman Empire' -- it isn't remotely modern, it isn't particularly evolutionary, and there isn't even a theory [to] it.
"

VR, quoting DarScripture: "Genetic drift — along with natural selection, mutation, and migration — is one of the basic mechanisms of evolution.

In each generation, some individuals may, just by chance, leave behind a few more descendents (and genes, of course!) than other individuals. The genes of the next generation will be the genes of the "lucky" individuals, not necessarily the healthier or "better" individuals. That, in a nutshell, is genetic drift. It happens to ALL populations — there's no avoiding the vagaries of chance …
"

We are forever being told by 'Science!' fetishists -- except for the times when they find it convenient to deny it -- that one of the most important properties, and arguably the most important property, of a scientific theory is that one can use such a theory to make testable predictions about the physical/natural world of mechanical cause-and-effect. And, further, that whatever else it is, a “theory” that cannot make testable predictions about the physical/natural world of mechanical cause-and-effect is not scientific.

The above is commonly expressed as the dictum that, at minimum, scientific theories are falsifiable.

So, regardless of what the scientistes may admit, a “theory” that can with equal facility “predict” both ‘A’ and ‘not-A’, is not only not falsifiable, it is not even a theory.

Now, look again at the definition of “genetic drift” in the context of the (quite silly) claim that 'modern evolutionary theory' is a *scientific* theory. Think about this; use your mind: realize that 'modern evolutionary theory' can, with equal facility, “predict” (*) both ‘A’ and ‘not-A’. That is, 'modern evolutionary theory' not only is not scientific – for one simply cannot use it to make falsifiable predictions about the physical/natural world of mechanical cause-and-effect – but it does not even rise to the status of theory in the first place.

(*) the reason I use scare quotes there is that the only things 'modern evolutionary theory' can “predict” are things already known, or at least believed, to be true.

Ilíon said...

Making falsifiable predictions about the future evolution of the lowly dandelion is too much for 'modern evolutionary theory'. Or, at any rate, it is too much for 'modern evolutionary theorists'.

Don McIntosh said...

[Channeling my inner Dan Aykroyd]

Victor, you ignorant creotard.

There is no "problem" for "Darwinism" (evolution), and here's the proof:

1. Evolution is a fact of science.
2. A fact of science doesn't have "problems."
3. There are no "problems" for evolution.

Weird, the above was supposed to be tongue-in-cheek. But it sounds eerily similar to the reasoning I've actually heard from serious, well-educated and otherwise rational defenders of Darwinism.

This just goes to show that Poe's Law is not restricted to Christian fundamentalists, but applies to fundamentalists of all stripes.

jdhuey said...

Let me recommend the book "Arrival of the Fittest" by Andreas Wagner. He gives a detailed examination on how biological innovation is introduced into a population.

William said...

Victor,

Why things are beautiful isn't biology, it's aesthetics, so I agree with you there. I think evo-psych is a mere just so story as far as beauty goes.


grodrigues said...

@William:

"and things just drifted in that direction (genetically and epigenetically) for the maples."

The problem with this is that it is dangerously close to a vacuous non-explanation.

William said...

Yes, and some predictions are of the shape of the population of events, and cannot be accurately made of a particular instance. So those who expect a fully detailed and deterministic system of explanation are going to complain.

Genetic drift is not (and could never be) an explanation of any particular sub-detail, but just of the fact a change in that general way happened at all.

We cannot explain the height and timing of a given wave exactly, just because we know that the wind makes waves.

Lack of exact detail in an explanation is not the same as total vacuity.

Gyan said...

"scientific theories are falsifiable."
Per Popper but other views of what constitutes sciences exist and are respectable.

Ilíon said...

Gyan, "we can say whatever shit we want to say and you have to accept it as The Truth because we are 'scientists'" is *not* a respectable view.

Ilíon said...

grodrigues: "The problem with this is that it is dangerously close to a vacuous non-explanation."

grodrigues is practicing the English art of understatement.

The truth is that *all* Darwinistic "explanations" are "dangerously close to a vacuous non-explanation".

Shoot! Even the bit of Darwinism that *isn't* vacuous is all but spelled out in a certain infamous "Bronze Age religious text".

Ilíon said...

"Nonadaptive order: a problem for Darwinism?"

Everything -- literally everything -- is "a problem for Darwinism", because the "success" of Darwinism critically depends upon the Darwinists not even understanding their own (pretend) theory.

Here is a piece by Cornelius Hunter that illuminates what I said: Debate Redux: The Myth of Natural Selection

William said...

I like the idea of the current world being selected by the equivalent of Molinism, but as a solution that permits a pervasive within-system indeterminism, as well as free will.

In defense of natural selection, though, I think that Cornelius Hunter is committing an error which matches the original posting's error: requiring that the mechanism of evolution produce a world with exactly our species. Whereas the more likely outcome of another take from the beginning on evolution would likely have at the very least different leaves on the equivalent of maples, and probably overall contain a very different set of organisms, and maybe no organisms at all. If we allow the current world to be just one of a very large set of possible outcome worlds, then most of the statistical stumbling blocks are removed, since the numerator (divided by the combinatorial explosion) becomes very much larger than 1.

Ilíon said...

William,
In the world posited by Darwinism -- according the world-view the holding of which is the only *reason* for a person hold to Darwinism -- there is no such thing as "within-system indeterminism".

Moreover, free-will and indeterminism are different in kind, not in degree. To attempt to reduce a free-will act to an indeterminate state or event is to deny the reality of the very thing one is claiming to have explained.

Gyan said...

Illon,
It is explained by the logic of evolution itself why biological evolution does not lend itself to predictions. That all sciences must follow the logic of falsification is merely an opinion that theists use to denigrate evolution. Biologists know that falsification-ism is irrelevant to their work and aren't least bothered.

grodrigues said...

@Gyan:

"That all sciences must follow the logic of falsification is merely an opinion that theists use to denigrate evolution."

This is what is commonly known as "slander".

"Biologists know that falsification-ism is irrelevant to their work and aren't least bothered."

This is false and would be startling news to many biologists. I will not say all, because I am not a biologist and actually know (or care) little for biology.

I hasten to add that there is a sense that you are correct, but for the wrong reasons. Falsificationism is irrelevant to *Evolution theory* in part, and only in part, not because the "logic of falsification" is irrelevant to the science of Biology (far from it), but because Evolution is not science in the proper sense but History. As Aristotle said, there is no science of the particular only of the general, and History is the study of the particular -- the particular, actual History of *this* concrete particular universe.

Of course History is a science, but science construed here as systematic body of knowledge with its own particular methods, etc. not science in the modern sense of the empirical sciences such as Physics, Biology, etc. for which Falsificationism is highly relevant and a distinguishing hallmark.

And I should also add that my complaint, which was not answered, was that "it is dangerously close to a vacuous non-explanation". Lack of predictions or details, or whatever, are the symptom not the cause.

Ilíon said...

The reader may recall this link that Plank's Length posted the other day. *That* is what you get when you attempt to decouple modern empirical science from falsification, which is to say, from empiricism.

The spinning into absurdity break-down in modern science that we are witnessing in our lifetime is a direct result the (enforced) pretense that 'modern evolutionary theory' is scientific, in the restricted sense of 'modern science'.

William said...

grodrigues:

Consider a genetically neutral (because in a nonexpressed gene) single nucleotide replacement mutation. In that organism's population, one might trace that mutation's future, and if we look at the individual organism's reproductive outcomes we can explain in detail why that allele had its future population outcomes.

But explanation has to stop somewhere. Once we look at the individual happenstance of one animal out of thousands and how many of its offspring individually survive, when do we stop asking why a particular event happened to a particular individual in that particular way, that affected its survival?

If you are going to call population genetics vacuous, then all human explanation of what has already may be ultimately vacuous, if you drill down enough.