Number of posts : 899 Age : 58 Registration date : 2008-03-30
Subject: Human Intervention Changes Evolution Fri Dec 25, 2009 12:20 am
Dr. Martin Schaefer from the University of Freiburg in Germany led a team that has studied the changing behaviour of the blackcaps. The research has shown that it is not just the migratory patterns that have changed, the birds themselves are changing physically. The results of the work of Dr. Schaefer and his colleagues have been published online by Current Biology
What they found through blood samples and other observations was that the birds that over-wintered together were also mating together creating an isolated reproductive group; which would be the first step on the evolutionary path to a new species.
Gill quotes Dr. Schaefer as saying: “This tells us that by feeding birds in winter we...produce an evolutionary split. And we have produced these initial steps in as little as 50 years.”
The changes observed are not dramatic – a slightly altered wing shape and beak – but they are significant.
The rounder wings have developed because this gives the birds an advantage in maneuvering at the expense of long-distance flying, which they no longer need.
Longer and thinner beaks have developed because they no longer need the shorter, thicker beaks that were suitable for eating fruit such as olives.
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Subject: Human Intervention Changes Evolution 
Fri Dec 25, 2009 12:20 am