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[Michaelangelica]

ince the 1930s textbooks have taught that the New World's first inhabitants, known for the town in New Mexico where their spear points were discovered, walked from Siberia to Alaska about 13,300 years ago. The Clovis people were believed to be highly mobile nomadic hunters, never settling in one place, instead surviving on massive mammoths, mastodons and ancient bison.

But in excavations starting in 1998 Gault has revealed that Clovis people lived at the site for extended periods over a span of 300 years, says Michael Collins, a research associate with the Texas Archeological Research Laboratory. The evidence? Scientists have found numerous tools manufactured from local stone, used until they were worn, then repaired repeatedly until they finally were discarded. In other words, Paleo-Indians were members of a settled community. "We're redefining Clovis," Collins says.

Texas Archaeological Dig Challenges Assumptions about First Americans: Scientific American

J

uly, 2008 in Biology | 39 comments | Post a comment
The Migration History of Humans: DNA Study Traces Human Origins Across the Continents
DNA furnishes an ever clearer picture of the multimillennial trek from Africa all the way to the tip of South America

By Gary Stix
Scanning broadly has produced global migratory maps of unprecedented resolution, some of which have been published only during recent months. The research provides an endorsement of modern human origins in Africa and shows how that continent served as a reservoir of genetic diversity that trickled out to the rest of the world. A genetic family tree that begins with the San people of Africa at its root ends with South American Indians and Pacific Islanders on its youngest-growing branches.

The study of human genetic variation—a kind of historical Global Positioning System—goes back to World War I, when two physicians working in the Greek city of Thessaloníki found that soldiers garrisoned there had a differing incidence of a given blood group depending on their nationality. Beginning in the 1950s, Luigi Luca Cavalli-Sforza started formalizing the study of genetic differences among populations by examining distinct blood group proteins. Variations in proteins reflect differences in the genes that encode them.

The Migration History of Humans: DNA Study Traces Human Origins Across the Continents: Scientific American