Skip to comments.Adaptation Plays Significant Role in Human Evolution
Posted on 01/20/2009 11:08:20 AM PST by Boxen
For years researchers have puzzled over whether adaptation plays a major role in human evolution or whether most changes are due to neutral, random selection of genes and traits.
Geneticists at Stanford now have laid this question to rest. Their results, scheduled to be published Jan. 16 online in Public Library of Science Genetics, show adaptation-the process by which organisms change to better fit their environment-is indeed a large part of human genomic evolution.
"Others have looked for the signal of widespread adaptation and couldn't find it. Now we've used a lot more data and did a lot of work cleaning it up," said Dmitri Petrov, associate professor of biology at Stanford University and one of two senior authors of the paper. "We were able to detect the adaptation signatures quite clearly, and they have the characteristic shape we anticipated."
All genetic mutations start out random, but those that are beneficial to an organism's success in their environment are directly selected for and quickly perpetuate throughout the population, providing a uniform, traceable signature.
(Excerpt) Read more at sciencedaily.com ...
Shannon’s Information Theory lets you measure the amount of information carried by a signal, and is quite applicable to genetics. However, information cannot be created randomly; only entropy can. Yes, mutations can happen, and sometimes that can make an organism more fit by losing information (say, by making a deformed protein that makes it immune to some kind of virus or whatnot), but overall, information is still lost to entropy, and the organism is hindered by its “adaptation”.