Saturday 6 February 2016

Zinjanthropus

It's Mary Leakey's birthday today 6th Feb 1913. She's a pretty good role-model for a career as woman-in-science if you like women who are tear-aways who shake up the system a bit.  She was the daughter of an itinerant artist Erskine Nicol who tooled about the empire making watercolours of exotic locations for sale to retired colonels and romantic bank-clerks back home in England. She was well connected in the upper-classes with good anti-slavery credentials in her ancestry. That gave her a certain freedom to pursue her own slightly off-centre dreams without the requirement to get a job behind the counter in Woolworths.  She lived as a child in USA, Italy, France and Egypt.  She became fluent in French and picked up an interest in the ancient past as well as picking up - and classifying - an ever increasing collection of archaeological artifacts.

In 2013 she was tribbed with a UK postage stamp in an eclectic series entitled "Great Britons" who were all born in 1913 or 1863. You'll never guess who else made the cut. She met Louis Leakey on a dig and later was recommended to him as a scientific illustrator for his forthcoming book. He was the brightest and best of  the palaeo-anthropologists at Cambridge University.  He was ten years older than her and married and his affair with Mary was received with shock and scandal in the narrow academic community in which they moved. The two of them tired of being cold-shouldered at Cambridge parties and more or less emigrated to East Africa to pursue a lifetime in fossil-hunting and adventure. She, they, were happier out there in the sun and scrabbling about in the dirt for artefacts and fragments of fossilised bone. She is most famous for discovering the skull of a fossil hominid which Louis named Zinjanthropus boisei, which was renamed as Paranthropus boisei before eventually coming to rest [for most people] as Australopithecus boisei. You may ask what-matter they call a skull but the naming of parts is fraught with politics and ambition and encourages particular ways of interpreting the world. boisei is an example of a robust hominid built like a gorilla with massive brows and and a sagittal crest like a mohican haircut to support massive muscles to the jaw. The Leakeys convinced themselves that this was one of our ancestors and wanted to trib a) Zinj an old Arab slaver's name for the Kenya Coast and b) Charles Boise, a financial backer. It is clear to us now that boisei is a side-branch collateral relative rather than a direct ancestor.  "Paranthropus" recognises this off-shoot idea. Australopithecus is now the grab-bag for a clatter of different species and varieties of fossil hominids which preceded and lived in parallel with members of our genus HomoAustralopithecus includes A. afarenis "Lucy" a much slighter creature who pre-dated boisei and seems more on our direct track. This robust/gracile branching is a repeated theme in primate evolution: Gorilla gorilla vs chimpanzees Pan troglodytes and Pan paniscus then A. boisei vs A. afarenis and A. africanus then Homo neanderthalensis vs Homo sapiens.
Mary Leakey also discovered the Laetoli foot-prints: trace-fossils of  two people - quite possibly/poignantly mother and daughter - walking across some volcanic dust.  "People"? probably not; because these footprints date to 3.6 mya and there's no evidence that they could talk. But walking upright frees up the hands to make things: like the stone tools that Mary Leakey was digging up - and classifying - next to more and more fragments of hominid fossils. The Leakeys mentored Jane Goodall, who researched living primates in East Africa as the Leakeys continued to research the dead. Tradition, dynasty . . . Mary and Louis had three sons Jonathan, Richard and Philip who grew up in and around the work camps and digs that their parents were working in. Jonathan is now a businessman in Kenya but as a young chap he found OH 7 [Olduvai Hominid 7] "Jonny's Child" the type specimen for Homo habilis.  My old boss used to say of another H. habilis specimen "ER1470 could have driven a bus"; and that species has much better credentials for being a direct ancestor than Zinj. Read a bit more, better informed about Mary Leakey.

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