In the Sept. 21 issue of Science, biologists write that they have produced the draft genome of the first roundworm parasite, Brugia malayi, which threatens millions of people in tropical nations with elephantiasis, a disease that results in tissue swelling and skin thickening.
(Science)
Discoveries
Skeletons help fill missing link
In the Sept. 21 issue of Science, biologists write that they have produced the draft genome of the first roundworm parasite, Brugia malayi, which threatens millions of people in tropical nations with elephantiasis, a disease that results in tissue swelling and skin thickening.
(Science)
The scarcity of early human fossils has obscured key periods of our evolution, and often discoveries that fill in the gaps raise more questions than they answer. A team led by David Lordkipanidze of the Georgian National Museum has uncovered four partial skeletons to accompany skulls they uncovered earlier in Dmanisi, Georgia. The bones date from 1.77 million years ago, making them the oldest early humans known to have lived in temperate Eurasia, and show a curious mosaic of advanced and primitive traits. Their brains were less than half the size of modern humans, close to those of one African contemporary, Homo habilis. Their bodies were about the size of Homo habilis. But their legs had evolved a shape well-suited for efficient long-distance walking, like those of their larger and more advanced African contemporary, the upright Homo erectus, which was once thought to have evolved from Homo habilis, but may have instead lived alongside them.
BOTTOM LINE: Early humans in Asia were "very variable and not completely modern, but modern in many important respects," says Harvard anthropologist Dan Lieberman, who was not involved in the study but wrote a commentary that accompanied it.
CAUTIONS: The relationship between Homo habilis and erectus is still unclear, and we have little fossil evidence of the crucial origins of the genus Homo from its australopithecine ancestors.
WHAT'S NEXT: Scientists are searching for more rare fossils of early humans, particularly to fill the gap between about 2.3 million and 2 million years ago when Homo first evolved.
WHERE TO FIND IT: Nature, Sept. 20
JEFF HECHT
© Copyright 2007 Globe Newspaper Company.
