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Dr. Guillermo Paz-y-Miño C. — © 2011
Department of Biology, University of Massachusetts Dartmouth
Illustration by JH Matternes, click on image to access more of artist’s fantastic work
An African American blogger just settled an online dispute over human origins by asserting, with magnificent wisdom, that “all history is Black History.”
His co-bloggers had rejected the evolutionary significance of a recent fossil discovery in Hadar, Ethiopia, of a 3.2 million year old foot bone belonging to Australopithecus afarensis –the famous Lucy’s lineage– which has unveiled hints about the locomotion habits of early hominids. The clever blogger brought reason into a trivial exchange of brain gas among sponsors of one wrong over another belief about human ancestry. “Deal with it” –that is with our common African heritage– were his last gentle, yet shut-up devastating words.
The left fourth metatarsal bone described in Science magazine by professors Carol Ward, William Kimbel and Donald Johanson, the latter discoverer of the very Lucy, also in Hadar, in 1974, tells a compelling story: Lucy’s relatives walked upright, a conclusion awaiting unequivocal evidence for almost four decades, and the tiny bone just provided it in its complex anatomy. The now famous AL-333-160 three-inch bone (in paleontology identification numbers are precious) resembles the bipedal human ‘arched’ metatarsals –shock absorbers for “walker apes”– and differs from the quadrupedal chimpanzee’s, bonobo’s and gorilla’s, which are more elongated.
AL-333-160 left fourth metatarsal in dorsal, lateral, medial, plantar, and proximal views (Ward et al. Science 2011;331:750-753). Click on image to explore the Science magazine article and to download the power point slide for teaching.
Lucy, herself 3.2 million years old, still is the most famous, although not most significant, hominid fossil ever described. Ardi, a 4.4-million year old almost complete skeleton discovered in Aramis, Ethiopia, by Tim White in 2009, and Toumai, a 7-million year old hominid skull found in Chad by Michel Brunet in 2001, are Lucy’s fair competitors.
Lucy was brought to celebrity status by her always calculating manager, Johanson, who named her after The Beatles song “Lucy In The Sky With Diamonds,” thus launching her popularity into textbooks, anatomical reconstructions, cartoons of a stocky yet friendly smiling “ape cousin,” and full-body hairy depictions of her 3-feet tall “reconstructed flesh” at museums and exhibits of human origins.
Lovely Lucy Australopithecus afarensis, for image credit and additional images click on her rostrum
For bloggers and alike who question the African origin of humans, of which Lucy’s tale is only part of the story since she was also born to common ancestors between her family and ours, the enigma has long been solved. But the journey to acknowledge that “we are all Africans” has been tortuous.
“…the journey to acknowledge that ‘we are all Africans’ has been tortuous…”
In The Descent of Man, 1871, Charles Darwin reasoned: “In each great region of the world the living [animals] are closely related to the extinct species of the same region. It is therefore probable that Africa was formerly inhabited by extinct apes closely allied to the gorilla and chimpanzee; and as these two species are now man’s nearest allies, it is somewhat more probable that our early progenitors lived on the African continent than elsewhere.”
Darwin’s inference was brilliant, but it took more than a century to be definitely embraced by scholars. This “Out of Africa” hypothesis has been corroborated by DNA evidence, physical anthropology, and specimens.
The out-of-Africa journey and dispersal of modern humans. Click on Human Migration image from National Geographic to access high-definition map
Indeed ancient forms of Homo sapiens evolved to anatomically modern humans entirely in the Ethiopian realm, about 200,000 years ago. And they walked out of Africa to populate the planet, which can be demonstrated with fossils and genetic pedigrees of indigenous peoples worldwide. Even human languages follow a pattern of geographical distribution consistent with a common origin in Northeastern Africa and nearby Mesopotamia.
More recently, the “Multi Regional” hypothesis of human origins, which counters the out-of-Africa postulate by conceiving an overall hybridization and integration of all world Homo species, including archaic forms, such as the Asian Peking Man, Homo erectus, and modern variants, such as the Northeast African and Southern European Homo sapiens, into a unified single Homo sapiens sapiens, has regained closer attention –after losing power during the 1990s– due to the discovery of shared genetic features between us and Neanderthals, a fairly modern human variety which became extinct 40,000 years ago.
The single origin or Out of Africa idea is nowadays well accepted among scientists. And even if the multi-regional hypothesis regains strength, all ancestral forms of hominids seem to coalesce to Africa. Disagreements among scientists do not invalidate science as believed by misinformed illiterate bloggers, who insist that there are not enough fossils to account for evolution or that the questions about human origins are far from being answered.
As much as our African American blogger so intuitively stated that all history is, ultimately, Black History, Darwin’s own writings from 1871 continue to alert us about the essence of belief-based debates: “It has often and confidently been asserted, that man’s origin can never be known: but ignorance more frequently begets confidence than does knowledge: it is those who know little, and not those who know much, who so positively assert that this or that problem will never be solved.” — © 2011 by Guillermo Paz-y-Miño-C. all rights reserved
Two African Americans celebrating color and creativity, photo courtesy Rashida Charles