PARIS – The pygmies of West Africa evolved their short stature independently and very differently from their East African cousins, researchers say.
The finding, which has been published in the journal Nature Communications, is being viewed as evidence for the theory that dwarfism is an adaptation to environmental conditions — in this case life in an equatorial rainforest.
It also shows human traits such as growth rate can evolve “within a relatively short period of time,” something which has allowed humankind to adapt rapidly and colonise the planet.
Scientists have long sought to understand how the physical development of pygmies, who derived from a common Bantu-speaking ancestor about 60,000 years ago, differs from that of other human groups.
Are they born smaller? Or do they stop growing at some point?
The new study, based on growth data from several hundred members of Cameroon’s Baka pygmy tribe from birth to adulthood, found their growth pattern differed not only from that of taller races but also other pygmies.
In the Baka, babies were normal size at birth but their growth slowed significantly during the first two years of life.
It “then more or less follows the standard pattern, with a growth spurt at adolescence”, said the paper.
In the East African Efe and Sua tribes, people are smaller already at birth, previous observations have shown.
