Friday, 15 September 2017

Epigenetics Fuels Adaptation in Darwin’s Finches

Small ground finch (Geospiza fuliginosa). Image courtesy of Putneymark, CC BY-SA 2.0.

Joel Kontinen

Darwin’s finches should definitely be included in the list of arguments evolutionists should not use.

The tiny changes in beak size are not due to mutations and natural selection.

While they are featured in many Darwinian stories, facts do not support such storytelling.

New research suggests that the changes are due to epigenetics.

As a report posted on GenomeWeb puts it, “epigenetic variation between urban and rural populations of Darwin's finches … could underlie their adaptation to a new environment.”

The article goes on to say:

The Galápagos Islands only recently underwent urbanization, leading the researchers to wonder how organisms there are coping with speedy environmental change. By examining populations of two species of Darwin's finches, researchers from Washington State University and the University of Utah uncovered morphological differences between urban and rural populations of Geospiza fortis as well as epigenetic differences between urban and rural populations of G. fortis and G. fuliginosa. However, as they reported in BMC Evolutionary Biology last night, they found little genetic variation.”

They did not find much morphological change in the birds.

But when the researchers compared DNA methylation patterns — generated using methylated DNA immunoprecipitation (MeDIP) sequencing — they did find differences between rural and urban populations in both species.

The genes associated with the differentially methylated regions the researchers identified were typically involved in metabolism, cell signaling, and transcription, though they also differed by species. In particular, they noted that some differentially methylated regions were associated with genes in BMP/TGF-beta pathway. BMP4 expression, they added, has previously been linked to beak shape in Geospiza

Earlier research has also discovered that epigenetic factors help organisms to adapt to their environment.


GenomeWeb. 2017. Epigenetic Differences Found Between Urban, Rural Populations of Darwin's Finches. (24 August).