Squished Squirrels Evolve

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Squished squirrels evolve as road kill victims of "evolutionary illusions". New Scientist 22 April 2006, p11 reported they are doing things they "evolved to do, but at the wrong time or in the wrong place." Ecologist Joel Brown of University of Chicago, Illinois claims this explains why so many squirrels end up being squashed on roads, because they spent millions of years evolving to cross open spaces as quickly as possible, "without wasting time watching for predators they wouldn't be able to escape anyway."

Another example is reported by Reed Bowman of Archbold Biological Station, Lake Placid, Florida who studied Florida scrub jays. Because of the abundance of bird feeders in suburban gardens urban jays have been breeding earlier than country birds, but the nuts provided by well-meaning humans are not suitable to feed the young, and there is not enough of their usual food, insect larvae, until later in Spring, so the young are not fed properly.

Other studies indicate bright lights can confuse migrating birds and emerging turtles. One example of adaptation to city life has been observed in European great tits. Urban birds sing at a higher pitch so they can be heard against the background din of the city. Brown commented: "Most of these species have just begun to adapt to human environments. It's a cool natural experiment."

Editorial Comment: Whatever is happening to animals and birds living in urban areas it is not evolution. Since road kill naturally selects inept squirrels, leaving only those which either made it across or don't cross roads, those creatures that survive have simply used their already existing ability to learn a new behaviour to cope with a changing environment. They will still be the same creatures. Those that cannot learn this will die out. Thus we have "survival of fittest" and "natural selection" but we do not have evolution. Adaptation, survival and selection are all real processes but they do not produce new living creatures. (Ref. ecology, urbanisation, niches)

Evidence News 19 July 2006

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