Evolution of New Species Requires Few Genetic Changes

Only a few genetic changes are needed to spur the evolution of new species — even if the original populations are still in contact and exchanging genes. Once started, however, evolutionary divergence evolves rapidly, ultimately leading to fully genetically isolated species, report scientists from the University of Chicago in the Oct. 31 Cell Reports.

“Speciation is one of the most fundamental evolutionary processes, but there are still aspects that we do not fully understand, such as how the genome changes as one species splits into two,” said Marcus Kronforst, PhD, Neubauer Family assistant professor of ecology and evolution, and lead author of the study.

To reveal genetic differences critical for speciation, Kronforst and his team analyzed the genomes of two closely related butterfly species, Heliconius cydno and H. pachinus, which only recently diverged. Occupying similar ecological habitats and able to interbreed, these butterfly species still undergo a small amount of genetic exchange.

Kronforst and his team plan to characterize the remaining four divergent genome areas to look for functions important to speciation. They also are studying why species more commonly arise in tropical areas.  “It is possible that this type of speciation, in which natural selection pushes populations apart, has been important in the evolution of other organisms. It remains to be seen whether it is a common process though,” Kronforst said.

Read the full article here.

© The UCLA Institute for Society and Genetics. All Rights Reserved.

X