A walk back through evolution.
Three hominids made some remarkable impression 3.5 million years ago. They walked across damp volcanic ash that later hardened and preserved their footprints at the Tanzanian site of Laetoli. Since the 1978 discovery of the Laetoli hominid trails, anthropologists have debated whether the footprints belong to Australophthecus afarensis -- the earliest known hominid species, which includes the famous "Lucy" skeleton--or represent a separate species linked to the Homo line.
The argument seems unlikely to be resolved until many more early hominid fossils are found at Laetoli and elsewhere. But the first detailed study of the gaits and footprints of modern people who walk barefooted indicates the Laetoli prints are much like those of Homo sapiens and were probably not produced by Lucy's relatives, reports Russell H. Tuttle of the University of Chicago.
Tuttle and his co-workers studied 70 Machiguenga Indians in Peru. The sample included an almost equal number of males and females between ages 7 and 67. TheMachiguenga negotiate a rough mountainous terrain without shoes.
Machiguenga individuals usually walk with their feet close together and aligned along a straight line (as opposed to walking with feet pointed out or in). Their feet, broad compared with the feet of people who wear shoes, have prominent arches, Tuttle says. Machiguenga toes fan out, with large gaps between each toe.
The shape of Machiguenga feet and their placement while walking resemble the Laetoli prints, Tuttle concludes.
Further investigations should concentrate on barefooted groups living in relatively flat savannah regions similar to the area traversed by the Laetoli hominids, he adds.
For now, Tuttle says, the possibility remains of a hominid species at Laetoli distinct from Lucy and other A. afarensis individuals found at the nearby Hadar site. The few toe bones found at Hadar curve downward in an ape-like manner. Hominids with curved toes could not have made the Laetoli footprints, he maintains.
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|Title Annotation:||Anthropology; analysis of footprints found at the Tanzanian site of Laetoli|
|Date:||Apr 22, 1989|
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