THURSDAY, April 26 (HealthDay News) -- Scientists have
identified genes linked to the small stature of Western African
Pygmies in Cameroon.
A large number of previous studies have pinpointed nearly 180
genes that influence height differences in European populations,
but this is the first genome-wide study of genes that affect height
in African pygmies.
On average, pygmy men are about 4 feet 11 inches. It hasn't been
clear why pygmies are so short, and scientists have suggested a
number of theories based on natural selection. For example,
pygmies' small size reduced their nutritional needs, helped them
better handle hot climates or enabled them to reach sexual maturity
at an earlier age.
Along with identifying genes that may be responsible for
pygmies' small size, this study, led by researchers at the
University of Pennsylvania, also suggests that hormonal pathways
and immune system regulation may have been the evolutionary drivers
of pygmies' short stature.
The study appears April 26 in the journal
"There's been a longstanding debate about why pygmies are so short and whether it is an adaptation to living in a tropical environment," senior author Sarah Tishkoff, a professor in the genetics and biology departments at Penn, said in a university news release. "I think our findings are telling us that the genetic basis of complex traits like height may be very different in globally diverse populations."
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