Aussie Snakes Evolving

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Aussie snakes evolving, according to articles in BBC News, 8 Dec 2004, and Proceeding of the National Academy of Sciences (PNAS) , vol. 101 p17150, 7 Dec 2004. The BBC article begins: “Snakes in Australia have evolved to counter the threat of invasive poisonous cane toads, scientists have found.” Cane toads were introduced into Australia in the 1930's and have had a devastating effect on native animals that normally eat frogs and toads, because the toads have highly toxic chemicals in their skin. Ben Phillips and Richard Shine of the University of Sydney studied changes in head and body sizes of snakes in regions of Australia that have been invaded by cane toads. They compared two snakes, the red-bellied black snake and the green tree snake, both of which are poisoned if they eat cane toads, with two species that are less susceptible to cane toad poison. They found that the susceptible snakes have smaller heads in comparison to their overall body size. Because snakes swallow their prey whole, snakes with smaller heads are limited to smaller prey and are less likely to eat a cane toad large enough to kill them. “These results provide strong evidence of adaptive changes in native predators as a result of the invasion of toxic prey” wrote Ben Phillips. PNAS classifies this study as an example of “contemporary evolution”

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Editorial Comment: The change in snake head size is not really adaptation, and is certainly not evolution. Adaptation is the built in ability of organisms to cope with changes in their environment. However, when a snake's head has grown big enough to eat a large poisonous cane toad, it is too late to adapt once it has eaten one. What has really happened over the last 70 years in cane toad infested regions of Australia is that snakes that already had large heads have been killed by eating cane toads, leaving only snakes that already had small heads to reproduce. ScienceNOW (the online news service associated with the journal Science) called it “survival of the pinheads”. This is the process of natural selection, but selection, natural or otherwise, is not evolution. Creation Research has said this many times, and will go on saying it. To select something is to choose it from an already existing group of alternatives. It does not explain how the alternatives came into existence, and it certainly does not make them change into other alternatives. All it does is eliminate some alternatives, and this is the opposite of evolution. (Ref, snakes, toads, adaptation)

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