Eric Walker added Science | AAAS to First humans in North America

Eric Walker added Frontiers | Human Occupation of the North American Colorado Plateau ∼37,000 Years Ago to First humans in North America

Eric Walker added Science | AAAS and Frontiers | Human Occupation of the North American Colorado Plateau ∼37,000 Years Ago to First humans in North America, and added First humans in North America to Upper Paleolithic

Eric Walker added a number of topics and a number of links to Upper Paleolithic, and added Upper Paleolithic to Paleolithic