New scientific approach could reveal pieces of human DNA favored by evolution

Washington, January 10 (ANI): In a new research, scientists have come up with a method that could reveal the pieces of human DNA that have been favored by evolution because they confer beneficial traits.

The research, by scientists from the Broad Institute of Harvard and MIT, describes a method for pinpointing the preferred regions within the human genome that offers greater precision and resolution than ever before, and the possibility of deeply understanding both our genetic past and present.

"It's clear that positive natural selection has been a critical force in shaping the human genome, but there are remarkably few examples that have been clearly identified," said senior author Pardis Sabeti, an associate member of the Broad Institute of Harvard and MIT and an assistant professor of organismic and evolutionary biology at Harvard University.

"The method we've developed makes it possible to zero in on individual genes as well as the specific changes within them that are driving important evolutionary changes," he added.

"In the human genome, positive natural selection leaves behind very distinctive signalsm," said co-first author Sharon Grossman, a research assistant at Harvard University and the Broad Institute.Earlier methods for detecting these signals are limited, highlighting relatively large chunks of the genome that are hundreds of thousands to millions of genetic letters or "bases" in length, and that can contain many genes.

Sabeti, Grossman and their colleagues wondered if there might be a way to enhance this genomic search.

Because existing methods for detecting natural selection each measure distinct genomic features, the researchers predicted that an approach that combines them together could yield even better results.

After some initial simulations to test their new method, the research team applied it to more than 180 regions of the human genome that are thought to be under recent positive selection, yet in most cases, the specific gene or genetic variant under selection is unknown.

The researchers' method, called "Composite of Multiple Signals" (CMS), enabled them to dramatically narrow the size of the candidate regions, reducing them from an average of eight genes per region to one.

The number of candidate genetic changes was reduced from thousands to just a handful, helping the researchers tease out the needles from the haystack.

"The list of genes and genetic loci we identified includes many intriguing candidates to follow up," said co-first author Ilya Shylakhter, a computational biologist at the Broad Institute and Harvard University.

"For example, a number of genes identified are involved in metabolism, skin pigmentation and the immune system," Shylakhter added.

"This method allows us to trace evolution's footprints with a much finer level of granularity than before," said Sabeti. (ANI)