Birds of a feather

First large-scale study shows birds with faster rates of differentiation more likely to produce greater numbers of species

Date: June 13, 2017

Source: Louisiana State University

Biologists have always been fascinated by the diversity and changeability of life on Earth and have attempted to answer a fundamental question: How do new species originate?

Today, an implicit assumption in the discipline of speciation biology is that genetic differences between populations of animals and plants in a given species are important drivers of new species formation and are a key to understanding evolution. But that assumption has never been rigorously tested until now, according to a new paper published in the Proceedings of the National Academy of Sciences by scientists from LSU and the University of Michigan. University of Michigan evolutionary biologist Michael G. Harvey is the first author of the paper. He received his doctorate from LSU.

"Our results are of fundamental significance because there are researchers across the world studying speciation, and many of them investigate genetic differences between populations that are in the process of forming new species. These researchers assume those genetic differences are important for evolution, but this has never been shown in a satisfactory way. We are the first to show that the differences between populations studied by speciation biologists have been fundamental determinants of the formation of the diversity of life," said Harvey, a postdoctoral fellow in the Department of Ecology and Evolutionary Biology, in the laboratory of Daniel Rabosky at the University of Michigan.

Harvey and his colleagues compiled and analyzed an unprecedented data set containing genetic sequences from 17,000 individuals in 173 New World bird species. They demonstrated that species showing faster rates of genetic differentiation between populations are more likely to produce greater numbers of species over long evolutionary timescales.

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