Overview of Paleoindian taxonomy and migration hypotheses.

New research indicates an ice-free corridor may have been open for 20,000 years in North America and people could have moved southward even at Last Glacial Maximum. Isolation in America led to an adaptive radiation. A formal taxonomic review defines the early Paleoindian groups as Otomid-Sundadonts and compares conventional paleontological methodology with methods used in physical anthropology. Competing migration hypotheses are discussed.