Epigenetics may explain how Darwin’s finches respond to rapid environmental changes, according to new research published in the open access journal BMC Evolutionary Biology.
By studying rural and urban populations of two species of Darwin’s finches on the Galapagos Islands, researchers were able to show that while there was very little genetic variation, there were substantial epigenetic differences that could be related to environmental differences resulting from urbanization.
Sabrina McNew, PhD student at the University of Utah and lead author of the study said: “Urbanization of the Galapagos has happened relatively recently, so this is a good opportunity to study how animals respond to rapid environmental change.”
Genetic analysis of the birds revealed very little differences in genetic make-up between the rural and urban populations of both species. Analysis of DNA methylation patterns revealed significant differences between urban and rural populations for both species.
This study compared just two populations of finches so it cannot be said with certainty that urbanization is the key influencer of epigenetics or morphology. However the results are consistent with a potential role of epigenetic variation in rapid adaptation to changing environments. Future studies are needed to determine what direct effects DNA methylation has on physical traits, and to what extent these methylation patterns may play a role in evolution. Paper. (public access) – Sabrina M. McNew, Daniel Beck, Ingrid Sadler-Riggleman, Sarah A. Knutie, Jennifer A. H. Koop, Dale H. Clayton, Michael K. Skinner. Epigenetic variation between urban and rural populations of Darwin’s finches. BMC Evolutionary Biology, 2017; 17 (1) DOI: 10.1186/s12862-017-1025-9 More.
Between epigenetics and hybridization among closely related species, it is beginning to look as though Darwin’s finches, like Hollywood jeanswear, are marketed to the public mainly on branding.
Note: Darwinians will sometimes claim that Darwin’s finches demonstrate natural selection hard at work. But they are relying on public confusion. Natural selection can mean two different things. It can mean merely what Lynn Margulis said in an interview with Suzan Mazur, that not all life forms that come into existence can live. Only the traits of survivors can be passed on in some form. No one doubts that.
The second meaning is the Darwinian claim that the process of natural selection as above, acting on random mutations, creates large amounts of complex specified information by itself, turning cows into whales, etc. There is little evidence that big changes happen so simply.
And if the famed Darwin’s finches turn out to reflect the ceaseless back and forth flow of genetic information via epigenetics, hybridization, etc.—which results in an ongoing finch population of some type in the Galapagos—the finches are just another branded Darwin canard marketed to the public. They deserve better.
See also: New book: Evolution happens more quickly than we think
Darwin’s finches not a good example of Darwinian evolution
Epigenetic change: Lamarck, wake up, you’re wanted in the conference room!
The classic tale retold: