So who were they, and what happened to them? If they really are 40K years old then genetic and other data indicates that they are not the ancestors of today's American Indians. Instead, they must have been from an ealier group that went extinct.
"genetic and other data indicates that they are not the ancestors of today's American Indians."
That's not true. Various mtDNA studies (which are inherently unreliable) yield estimates of the ingress of various populations (meaning, an assumed single individual; all other mtDNA lineages having died out) which overlap the age assigned to these prints. And the vast majority of these studies reveal multiple populations entering the Americas at different times. The artificial barrier of Clovis dating is long gone.
Human Molecular Genetics, Vol 6, 41-46, Copyright © 1997 by Oxford University Press
http://hmg.oxfordjournals.org/cgi/content/abstract/6/1/41
C Lalueza, A Perez-Perez, E Prats, L Cornudella and D Turbon
Departament de Biologia Animal, Universitat de Barcelona, Spain.
Ancient DNA from bones and teeth of 60 individuals from four extinct human populations from Tierra del Fuego-Patagonia (Selknam, Yamana, Kaweskar and Aonikenk) has been extracted and the mitochondrial DNA (mtDNA) amplified by using the polymerase chain reaction. High- resolution analysis of endonuclease restriction site variation in the mtDNA and sequencing of its hypervariable non-coding control region, revealed complete absence of two of the four primary mitochondrial haplotype groups present in contemporary Amerinds, namely A and B. In contrast, haplogroups C and D were found in all but one sample with frequencies of approximately 38% and 60%. These results, together with the decreasing incidence of group A in more southerly latitudes in the American continent and the absence of cluster B above 55 degrees North in America and Asia, argue that the first settlers entering America 21000-14000 years ago already lacked both mtDNA lineages.