Looking around at the diversity present in human populations, it’s clear that humans have evolved and adapted over the millennia to be able to survive in a wide variety of environments. While it has been difficult for scientists to pinpoint exactly which genetic variations confer these adaptive phenotypes, teams led by Pardis Sabeti, of Harvard University and the Broad Institute, recently characterized a few of the variants that helped drive human evolution.

One of these, a mutation in the TLR5 gene, apparently changes the body’s immune response to flagellated bacteria, and may have led to increased bacterial resistance in human populations. Researchers determined this as a candidate adaptive variation using information from the fledgling 1000 Genomes Project, which has provided several other potential gene variants to investigate for future studies.

In a companion study, Sabeti’s group also uncovered a variation in the EDAR gene which correlates with increased amounts of sweat glands and thicker hair in both mice and humans. They postulate that the development of this allele approximately 30,000 years ago allowed humans to populate areas with more humid climates.

With these recent successes and the advent of new techniques, Sabeti believes there is great potential for even more elucidating discoveries about mechanisms of human evolution. “These two studies are the product of work done in this area for over a decade but can only now be made possible with the major breakthroughs in genomic technology,” Sabeti says. “I am struck by the ability of genomics to uncover the secrets of human history.”

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