There’s all kinds of evolution: Cliff swallows that build nests that dangle from highway overpasses have a lower chance of becoming roadkill than they used to because their progeny has developed shorter wingspans, so that they can dodge oncoming traffic.
It would be a great relief if this type of evolution would happen to the many birds that are killed by wind turbines every year.
When researchers looked at the numbers of swallows collected as roadkill each year, they found that the count declined from 20 birds a season in 1984 and 1985 to less than five per season during each of the past 5 years. During that same time, the number of nests and birds had more than doubled, and the amount of traffic in the area had remained steady, and the birds that WERE killed had longer wingspans than average.
On the ScienceNOW website, Sarah C.P. Williams quotes evolutionary biologist John Hoogland as saying, "We humans, because we’re changing the environment so much, are adding a new kind of natural selection to these animal populations."
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