Did Farmers Scatter Pygmy Populations Across Africa?

By Eliza Strickland | February 9, 2009 5:39 pm

pygmiesA genetic study has revealed the history of pygmy tribes scattered across western and central Africa, and it’s a story that might surprise the the people themselves. Pygmies are defined as groups of people whose adult men are typically less than 4 feet 11 inches in height, but they have little in common besides that physical characteristic and the word pygmy, which was foisted on them. But a genetic analysis of pygmies living in Gabon and Cameroon suggests that the first group of pygmies split off from other humans at least 50,000 years ago, and that ancestral population survived intact until 2800 years ago when farmers invaded the pygmies’ territory and split them apart [ScienceNOW Daily News].

European explorers first encountered pygmy populations in the 19th century and lumped them together under a name that Homer used in the Iliad to describe an African tribe of diminutive crane-fighters…. Many of their languages are also very varied, and the populations do not view identify any of the others as an ancestral group. “There is no such thing as a pygmy civilisation or identity” [New Scientist], says lead researcher Paul Verdu. Even today, the various populations often don’t know of one another’s existence. 

The genetic analysis of 604 individuals in nine pygmy groups and 12 nearby non-pygmy populations  showed that the pygmy groups are now very genetically different from each other, but that they share a recent common ancestor. This indicates that people of short stature evolved once in central Africa and then spread out, and puts to rest the notion that shortness evolved independently in each tribe because it was advantageous for life in the forest [ScienceNOW Daily News]. 

Exactly why pygmy populations diverged from one another is unclear, Verdu says. He hypothesises that an ancient migration of farmers and herdsmen across sub-Saharan Africa – dubbed the Bantu expansion – might have segmented pygmies living in West Africa [New Scientist]. Once they were scattered and isolated, the groups rapidly accumulated genetic differences, researchers say.

The study, published in Current Biology [subscription required], also found a strange twist: All the pygmy populations had genes from non-pygmy populations, but the outside groups had no pygmy genes. The researchers suspect this is because pygmy women tend to marry nonpygmy men and move to their homes, not vice versa. But these marriages often fail because of discrimination against low-status pygmy wives, Verdu says, and the pygmy women return to their pygmy groups with children who have DNA from their taller fathers [ScienceNOW Daily News].

Related Content:
DISCOVER: A Question of Size asks why bigger isn’t better for pygmy populations
DISCOVER: How Africa Became Black delves deeper into Africa’s genetic diversity

Image: Wikimedia Commons

CATEGORIZED UNDER: Human Origins
MORE ABOUT: genetics
  • Stephanie

    This article would be a lot better if it didn’t have so many errors. I have a hard time viewing someone as a credible source of info when they spell civilization as “civilisation”. I mean not to bash people that can’t spell, it’s just when you’re presenting an article you should be able to spell what you’re pretending to be an expert on. imo, lol.

  • Taki

    Stephanie, you are the one who can’t spell. “Civilisation” is the British spelling of “civilization”. Look it up in Merriam-Webster.

  • Jack

    HAHAHA, Hilarious. What a good definition of ignorance… or of haughty opinions?

  • Ariundar

    Wow. Talk about a troll. Coming onto a science website to complain about spelling. And to boot, you’re wrong. As stated above, “civilisation” is the British (and hence, correct) spelling.

  • eukaryote

    I’m so glad that there are comments sections attached to these articles, they contribute so much to the experience.

  • deedee

    What is interesting is how both the article, and the (first) comment speak of our (human) inability to accept diversity. We are only comfortable with what we know – and we are quick to judge others who are different and therefore “wrong” or inferior. I am willing to bet that the pygmy men were not effectively “faithful” to their pygmy women – or to their tribe and, therefore, did not spread their genes elsewhere – but rather women from other tribes judged them as being too short to be attractive or mate-worthy!

  • Charles

    We need to conserve Pygmies and their genetics (it may well be too late for the culture.)

    The genetics of small volume are very desirable for people moving off-planet. They use far less resources than us tall folk.

  • Paul Verdu

    The author of the Current Biology genetic paper to deedee

    I fully agree with you on the comment on our relation to Others.
    Otherwise, if you are willing to bet, I can tell you you’ll loose.
    First, we don’t really know what are mate choices criteria among pygmies and non-pygmies: I never met a single non-pygmy in Central Africa, that refered to the pygmies as being short in stature, nor a single Pygmy referring to himself as being of different morphology than neighbours. Non-pygmies have many attributes (more or less stereotypes), but never invoke short stature for pygmies. Pygmy stature is actually a western culture problematic…
    Second, could you explain to me what makes you think that women would despise small males for being unattractive and men would not do the same for small women ?
    Even if such asymetry was true and so common as you are suggesting, I am just wondering how come some non-pygmy populations in Central Africa are of short stature (for instance: Ba.Konjo in Western Uganda mesure on average less than 1,60m high).
    Third, there are no such thing as tribes among populations designated as pygmies.
    Finally, you forget about polygamy (polygyny to be precise) in Central Africa, which makes the word “faithfull” a bit more problematic to understand (theoretically…) in these cultures.

    It is strange that with your first sentence describing the need for an open mind accepting diversity, you feel the need to explain everything with one single not very subtle jugement assumption.

  • Paul Verdu

    To Charles:
    Do you know that the music record sent together with Voyager actually contained some sample of Aka pygmy music from Central Africa (recordings by Simha Arom), for outerspace intelligence to listen to ?
    However, I have no idea whether it was for their short stature… ;-)

  • http://www.wairaubarmystery.co.nz Jay Neall

    Just as increasing height is an adaption to cold weather, reducing height is a way of keeping cool. Not surprising to find people of small stature in hot environments. For the Pacific the authority is an academic, now retired, called Philip Houghton on the adaption of Pacific people to the cold in a maritime environment even if in the tropics. Height increases in an easterly direction across the Pacific. The other hot climate people who are small in stature that spring to mind are the Khoisan or Bushmen of southern Africa.

    In case you say, what about the Eskimos…this seems like a contradiction. Ancient Eskimo’s were so successful at keeping warm they have problems cooling off. The clothing they use (natural fur) and their houses/igloos resulted in overheating. Early anthropologists reported that their habitations were apparently so hot inside due to the good insulsating properties of ice that the sweat ran copiously off the occupants. The children were employed in ensuring that all visitors had plenty of water to drink.

    The people of the Pacific also show mixed DNA with female DNA (Mitochondrial DNA) different from male DNA. Enslavement and rape have to also be thrown into the mix. Mate choice may not be a choice at all.

  • Mako says

    My understanding is that height is not a cold adapatation. rather it is increased mass to skin ratio that keeps people warm. Eskimos/Inuits are short and stocky, ie a large amount of mass in relation to the amount of skin. Heat is lost through skin.
    Tallness is often a heat adapatation. Tall lean people have a high ratio of skin to body mass. Thus they lose heat very effectively.

  • Peter

    Mako is right, it’s a matter of physics, mammals in general are larger in colder climates and small bodies would have definite advantage in dense jungle, where speed and agility is needed, I suppose a pygmy woman would weep for her tall lummox of a son.

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