Brian Thomas returns to give us a classic for the Friday article, titled Deer in Black and White. This is classic Thomas (or a Thomas “classic”) both in that it makes for a perfect example of his failure to understand the process known as natural selection, and because the most recently published references come from 2010. His article – which is about white-tailed deer that have a genetic condition known as melanism which makes them dark coloured, which can be considered the opposite of albinism – is therefore not in any way “news.”
White-tailed deer are generally brown, but sometimes they can appear all black or all white. Photographer Richard Buquoi captured striking photographs of a dark fawn in 2010 and verified the images when some questioned whether his photographs were real: “I took the photos of the black fawn near Austin, TX. That area of central Texas seems to have a concentration of black ‘white-tailed’ deer, although it is still extremely rare to find them. This is a wild deer, but resides in a greenbelt near a neighborhood.”
Buquoi’s pictures are cited to this link, while the quote comes via a snopes page about the photos (which concludes that they do, in fact, exist). Thomas asks what causes this effect, and quotes the bolded portion of the following paragraph from the North American Whitetail:
Why would this be the case? The researchers admit that they aren’t sure, but they say the mutation likely has been perpetuated because it offers a survival advantage. Melanistic deer are concentrated along the region’s drainages, where cover is thick and a dark-colored prey animal would have an edge in avoiding detection. This trait also would serve them well in the upland juniper thickets found in the same part of Texas.
I’m sure Larry Moran and the like would be quick to point out that a vague and unproven (by which I mean not tested, demonstrated, or otherwise investigated) survival advantage should not simply be assumed to be the cause of the proliferation of this or any other trait – genetic drift could well be responsible – but as that is most certainly not the criticism that Thomas has chosen we’ll run with this adaptationalist position for the purposes of playing devil’s avocado.
There is another thing to consider with this quote: Brian asked what caused melanism, but that’s not what the article was talking about there. Instead, they were discussing the distribution of these animals in the United States. The magazine article does go on to explain that we don’t know a lot about the underlying genetics either, but this confusion between the processes that would cause there to be far more black white-tails in central Texas than anywhere else, and that which would create the trait in the first place, typifies Thomas’ own post. He says:
Well, the reason that evolutionary researchers would say that the trait was born from “survival advantage” is because that is standard Darwinian doctrine. But it does not express the results of scientific tests. Alternatives deserve consideration and could also be tested. For example, what if the darker color is not caused by an accidental mutation but by a purposefully designed genetic switch? Evolutionists have had trying times interpreting evidence for non-random mutation.
The idea that the trait would be a “survival advantage” is an allusion to the process of natural selection. This mechanism would have it that a deer with this trait was inherently more likely to have fawns and pass on the trait than one that did not, causing the proportion of deer with the trait to rise and thus explaining the elevated levels in those areas where this condition holds. But this requires that the trait exist in the first place, and thus does not explain nor even care about how it originally arose. Whether it appeared via a random (or otherwise naturalistic) or supernatural event is irrelevant as it would produce the same result.
Now, random mutations: I have been waiting for some time to have an excuse to talk about the supposed “evidence for non-random mutation,” but I won’t give you the full spiel today. What’s important now is to note that you need to be very careful to define what you mean by a “non-random mutation.” For example, some parts of the genome are generally more susceptible to mutations than others in a way that is decidedly non-random – this doesn’t mean that an individual mutation is random. Consider a man rolling dice at a table. The number that comes up in a given roll is “random” – to the same extent as a mutation is – but the number of dice he can roll in an hour is a product of various environmental factors (how fatigued he gets, how far he has to go to get the average dice back) and thus is not. The first paper cited for the final sentence in the above talks about how natural selection can influence the rate at which genome regions will mutate. The idea is that it may be advantageous for a specific region to mutate a lot (or a little), and so natural selection will favour those that have this advantageous trait and that can pass it on to their offspring. Perhaps the region contains genes related to the immune system: natural selection could favour animals that are more likely to mutate in this region as they are more likely to have rare variation that helps them fight off new diseases. This doesn’t mean that the mutations themselves are not random.
The second paper is even less useful for Thomas’ case: it argues that the reason why certain human mitochondrial DNA variants are more common in some areas than others (e.g. ‘M’ and ‘N’ dominating in Europe) is because of natural selection and not just genetic drift: it was more advantageous to be an ‘M’ type in Europe than an ‘A’ type, so there were more of them. That’s got nothing to do with whether the original mutations that produced these types were random or not. Why Thomas picked these two papers as his flagship evidence for non-random mutations will never be known – perhaps the titles sounded good? – but it suggests further that he has no idea what he’s talking about.
But there’s more:
And just because something “offers a survival advantage” does not mean it becomes a real creature feature. An instinct to avoid traffic would give squirrels a survival advantage, but they persist in trying to juke straight-rolling tires.
Yes, the trait has to exist and be heritable for natural selection to take effect – just making one up doesn’t work, especially when it’s as non-specific as an “instinct to avoid traffic.” And who’s to say that the squirrels of the past weren’t even more susceptible to such behaviours? It is hard to produce absolute results, especially when the subject is behaviour rather than something easy like coat colour.
So, the melanistic deer trait could have arisen by an accidental genetic mutation or by unfolding an aspect of a pre-planned genetic suite of coat color options. How would a biologist test these ideas?
A test for creationism? I told you this would be classic.
One would first need to discover the genetic cause of this trait—a difficult and costly task. Is melanism caused by a rare allele, a difference in regulatory sequence, a combination of these, or some other genetic cue? Even knowing that would not necessarily reveal the true history of how the allele or other DNA difference arose. Did it arise by mutation, or by any of the increasingly discovered numbers of genetic shuffling algorithms? The answers may not come soon.
…except, none of these would tell us whether or not the mutation was planned – and yes, the “genetic shuffling algorithms” are just large-scale mutations.
The way I have in mind that you could, actually, determine whether or not the cause was a random mutation would be rather difficult in a large animal like the dear. You’d be better off with something simpler that you can grow in a test-tube. You’d need to find your trait, and the conditions in which it would be useful. You would also need to know what the genetic underpinnings are – what mutation or gene it is – or some other method of easily and definitively determining whether or not the trait has arisen. You need to test under both normal conditions and conditions advantageous to the trait the chances of the trait arising – if the trait was more likely to appear when it was needed, then you may be on to something (maybe). But if it then turns out that it is more likely to arise because that situation causes mutations in general to be more common (i.e. the dice are being rolled more often, improving the odds of a given outcome in a given period of time but not per roll) then we have a case in a bit of a grey area, which we can talk about when (if?) it happens. A job for the “researchers” at the ICR?
Meanwhile, deer express other rare coat colors. Some visitors to the Seneca Army Depot in New York state have seen dozens of bright white deer among the hundreds protected there. They are not truly albino, because although their hair lacks pigment, their eyes and hooves do not. The ratio of white to normal brown deer has risen since the first observation of a white buck and fawn in the late 1940s.
From the perspective of Scripture, God would have given deer effective survival traits, including the potential for those traits to shift in preparation for survival or fitting into a changed environment as its generations fill the earth. But who is to say that He would not also have planted within the deer kind creative expressions of His painter’s palette?
So Brian’s “Goddidit” explanation doesn’t make any predictions, because it could just be that God is doing whatever he damn choses. Good to know for future reference. By the way, in other animals melanism increases the risk of cancer