title: The first four million years of human evolution.
authors.affiliation: Anthropology & Biology, Penn State University, University Park, PA 16802, USA.
authors.forename: Alan
authors.initials: A
authors.lastname: Walker
authors.forename: Chris
authors.initials: C
authors.lastname: Stringer
mesh_terms: D000885:Anthropology, Physical / Q000379:methods; D005075:Biological Evolution; D006801:Humans