Creationists constantly repeat their fictitious “law” that evolution can’t create new “information,” and therefore all new features of organisms must have a supernatural source.
We’ve previously written about two specific instances of new features that arose from the familar mechanism of gene duplication, followed by mutation in one of the duplicates to perform a new function. See ICR: Full Blown Reality Denial, about how E. coli developed the ability to digest citrate, and see also How One Gene Becomes Two Different Genes, about how Antarctic eelpout developed the ability to survive in frigid waters.
Now we have another example, and it’s far more spectacular because it involves the same new feature occurring in several species. At the PhysOrg website we read: Far from random, evolution follows a predictable genetic pattern, researchers find. Here are some excerpts, with bold font added by us:
Evolution, often perceived as a series of random changes, might in fact be driven by a simple and repeated genetic solution to an environmental pressure that a broad range of species happen to share, according to new research.
Princeton University research published in the journal Science suggests that knowledge of a species’ genes — and how certain external conditions affect the proteins encoded by those genes — could be used to determine a predictable evolutionary pattern driven by outside factors. Scientists could then pinpoint how the diversity of adaptations seen in the natural world developed even in distantly related animals.
“Is evolution predictable? To a surprising extent the answer is yes,” said senior researcher Peter Andolfatto, an assistant professor in Princeton’s Department of Ecology and Evolutionary Biology and the Lewis-Sigler Institute for Integrative Genomics.
Wow — convergent evolution is not only explainable, it may be predictable! Here’s a link to the paper: Parallel Molecular Evolution in an Herbivore Community. We’ll continue with the PhysOrg article:
The researchers carried out a survey of DNA sequences from 29 distantly related insect species, the largest sample of organisms yet examined for a single evolutionary trait. Fourteen of these species have evolved a nearly identical characteristic due to one external influence — they feed on plants that produce cardenolides, a class of steroid-like cardiotoxins that are a natural defense for plants such as milkweed and dogbane.
Or, as the creationists would put it, the Designer — blessed be he! — swooped down and gave these unrelated insects the genetic “information” necessary to feed on cardenolides. Let’s read on:
Though separated by 300 million years of evolution, these diverse insects — which include beetles, butterflies and aphids — experienced changes to a key protein … . The protein in these insects eventually evolved a resistance to cardenolides, which usually cripple the protein’s ability to “pump” potassium into cells and excess sodium out.
That ol’ designer must have been really hopping around to get all that done. We continue:
“The finding of parallel evolution in not two, but numerous herbivorous insects increases the significance of the study because such frequent parallelism is extremely unlikely to have happened simply by chance,” said Zhang [Jianzhi Zhang, a University of Michigan professor of ecology and evolutionary biology], who is familiar with the study but had no role in it.
If it’s unlikely to have happened by chance, you know what the creationists will be thinking. They’ll be screaming Oogity Boogity! as loud as they can. But perhaps there’s a rational explanation. Here’s more:
“It shows that a common molecular mechanism is used by many different insects to defend themselves against the toxins in their food, suggesting that perhaps the number of potential mechanisms for achieving this goal is very limited,” he [Zhang] said.
The researchers found that the genes of cardenolide-resistant insects incorporated various mutations that allowed it to resist the toxin. During the evolutionary timeframe examined, the sodium-potassium pump of insects feeding on dogbane and milkweed underwent 33 mutations at sites known to affect sensitivity to cardenolides. These mutations often involved similar or identical amino-acid changes that reduced susceptibility to the toxin. On the other hand, the sodium-potassium pump mutated just once in insects that do not feed on these plants.
They all had the same thirty-three mutations? The creationists will be screaming “irreducible complexity!” But wait — hold on — there’s a mechanism:
Significantly, the researchers found that multiple gene duplications occurred in the ancestors of several of the resistant species. These insects essentially wound up with one conventional sodium-potassium pump protein and one “experimental” version, Andolfatto said.
“These gene duplications are an elegant solution to the problem of adapting to environmental changes,” Andolfatto said. “In species with these duplicates, the organism is free to experiment with one copy while keeping the other constant, avoiding the risk that the new version of the protein will not perform its primary job as well.”
Aha! Just as in the other cases to which we linked, when you’ve got an extra gene to play with, it can mutate and thus provide new “information.” And random mutation can blunder into the same solution again and again. Well, that’s the explanation. One last excerpt:
“The power of what we’ve done is to survey diverse organisms facing a similar problem and find striking evidence for a limited number of possible solutions,” he [Andolfatto] said. “The fact that many of these solutions are used over and over again by completely unrelated species suggests that the evolutionary path is repeatable and predictable.”
Okay, that’s very nice, but what’s the creationist reaction? We’ve got one for you. It’s from the Institute for Creation Research (ICR). If you don’t know who they are, you can read about them in the Cast of Characters section of our Intro page. Their article is How Some Insects Can Eat Poisonous Plants.
We’ll skip their description of what the scientists did, because you already know that. All we care about is how they dismiss the science and cling to their mythology. Here we go, with bold font added by us:
Convergent evolution is conceivable, but it is scientifically meaningless unless researchers can actually detect it. Otherwise, to claim convergent evolution as these authors did is merely to beg the question of convergent evolution. In other words, the study authors ignored all non-evolutionary explanations for how these remarkably specific DNA differences arose.
Oh, we hadn’t noticed that. Yes, the biologists ignored “non-evolutionary explanations.” What might they be? You’ll see. On with ICR’s article:
Perhaps the DNA differences were directly created, or perhaps well-designed cellular systems put them in place at some point after creation.
Hey, those are two hot possibilities! Why don’t the creation scientists get to work researching them? They have their reasons. Behold:
The first possibility is blind to scientific experiment, which cannot directly investigate the past. No scientific experiment has verified the second possibility, but no experiment showed that these systems arose by convergent evolution either.
Satisfied? And now we come to the end:
These researchers conducted a rigorous study, to their credit. However, there was no scientific reason for them to have excluded origins possibilities that are at least equally valid.
So there you are. Teach the controversy!
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