A small bird discovered a few years ago in South America has followed a very different evolutionary path in the natural world.
New research by biologists from Argentina, the United States and Brazil focuses on how a species of South American sparrow – scientifically known as the Iberá capuchin – appeared in the animal kingdom .
Iberá capuchin is a very particular case of evolution. Comparing the bird to its cinnamon capuchin close relative of the genus Sporophila, the researchers found that genetic combinations of existing variants, rather than due to random mutations, lead to the formation of new species.
It is one of two internationally known examples of this evolutionary path, challenging typical assumptions about the formation of a new species.
Research published in the journal Science shows that Capuchins Iberá and Cinnamon have very similar genomes and are both capable of forming hybrids, but they rarely mate and behave separately despite sharing the environment. When searching for mates, individuals of the two species can distinguish which of their own species by the male’s feathers and song.
Usually new species are formed because some individuals in the population are isolated or separated from the rest by rivers, mountains or some kind of physical barrier. In the case of Iberá Capuchin, this barrier does not exist.
“The classic and most common pattern of evolution for a new species is the accumulation of genetic mutations when these species are separated by a geographic barrier for long periods, often millions of years.
But with Iberá, we have found that the shuffling of genes occurs much faster and that there is no geographic isolation. This is an evolutionary path we’ve never seen in birds, ”said co-author Irby Lovette, director of the Comprehensive Evolutionary Biology program at the Cornell University Bird Research Laboratory.
Previously, the only evolutionary species known as Iberá capuchin was the emperor fish of Lake Victoria.
The genus Sporophila includes recently developed songbirds found throughout South America. They branched out quickly with many species in their early stages of evolution.
Iberá capuchin is the most recent member of the genus and has only been described in the scientific literature since 2016. They have been observed in remote grasslands and wetlands in Iberá National Park in northern Argentina.
