Scientists are getting great insights into the forces which help in the development of and the evolution of new species through a research which involved the interbreeding between two species of howler monkeys which was conducted by scientists from University of Michigan (UM) in Mexico.
The elements of the study included the scientists making use of the primate hybrid zone that is used to identify parts of the genome which are likely to contain genes underlying speciation. The scientists look for and test for signals of the selection forces that shaped them.
The scientists conducted analysis of DNA samples that had conclusively shown that black and mantled howler monkeys interbreed and produced hybrid offspring. The researchers and scientists from UM researchers have been working for about two decades at the howler monkey hybrid zone in Mexico.
The scientists from UM conducted a comparison of the DNA from the black and mantled howler monkeys that have been living at the Tabasco hybrid zone with the DNA from the black and mantled howler monkeys that have been living far from the hybrid zone. This was done to examine the presence of reinforcement which is a process where natural selection of the strengthens of reproductive isolation is done by increasing genetic differences.
The tests showed that the genetic differences that were found between the two species w\that had been living in the hybrid zone were larger than the genetic differences that were found to exist between monkeys of these two species that lived on either side of the hybrid zone.
“We observed patterns in the genetic data suggesting that hybridization is playing a direct role in completing the speciation process by enhancing genetic differences between species,” said UM doctoral candidate Marcella Baiz, the study’s first author.
“We found a signal for multiple forms of natural selection driving species differences, including reinforcement,” Baiz said. “This result is particularly notable because empirical evidence for reinforcement is extremely rare, especially genetic evidence.”
“Speciation is a complex process that can be driven by direct and indirect mechanisms that interact to maintain and strengthen the process, and this study is one of the few natural examples that document this,” Baiz added.
The study was published on Dec. 22 online in the journal Molecular Ecology
(Adapted from Xinhaunet.com)