Pygmies’ Small Stature Evolved Multiple Times

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Pygmies’ Small Stature Evolved Multiple Times
By Carl Engelking
August 19, 2014

There are roughly half a million known pygmy people living in various tribes around the world, clustered mainly near the tropics in African and Southeast Asia. Anthropologists have long attributed the small body sizes of pygmy peoples to nutritional deficits resulting from harsh living conditions of the rainforest. But in a new study, researchers report that the human pygmy trait has a genetic basis, and has in fact evolved several times in different populations.

“We have found the strongest evidence yet that the pygmy phenotype is controlled by genetics,” Luis Barreiro, the study’s author, told National Geographic.

Tracking the Genes

Researchers focused on the Batwa pygmy people of Uganda’s Bwindi Impenetrable Forest, comparing them to their taller neighbors, the Bakiga people. The Bakiga were on average 5 inches taller than the Batwa, but they inhabit a similar environment, eat similar food and often intermarry. They collected blood and saliva samples from 169 Batwa adults and 61 Bakiga adults and compared their genomes.

The DNA analysis revealed 16 different genomic locations associated with the pygmy phenotype. These variations were in areas of the human genome that code for human growth hormone and bone formation. Further, the analysis revealed that the effects were cumulative: people with more of the Bakiga genes at these locations were also taller....

MORE at http://blogs.discovermagazine.com/d-brief/2014/08/19/pygmies-small-stature-evolved-multiple-times/