I recently read Charles C. Mann's 1491: New Revelations of the Americas Before Columbus, Second Edition, and was intrigued by the footnote on page 174:
[Aleš] Hrdlička's complaint about the lack of skeletal evidence [at Clovis] was unfair for another reason: paleo-Indian skeletons are extremely rare. In Europe, archaeologists have discovered scores of skeletons ten thousand years old or more. By contrast, fewer than a dozen reasonably complete skeletons of similar age have been found in North America (a few more exist in South America, although, as with the Lagoa Santa skeletons, their provenance is often unclear). "It's a big mystery why we don't find the burials," the University of Vermont archaeologist James Petersen told me. "Some Indians will tell you that their dead all moved to a spiritual plane, and that's about as good as any answer that we've got."
I've Googled for more information about this (searches like
rarity of paleo-Indian skeletons), but what I've found has just left me with more questions. For example:
"Paleoamerican skeletons are rare for several reasons," [James] Chatters said. "The people themselves were few; they were highly nomadic and seem to have buried or cremated the dead where they fell, making the locations of graves unpredictable; also, geologic processes have destroyed or deeply buried their graves." [link]
These statements seem possible, but seem to be at odds with Mann's footnote (and with his thesis more generally).
I obviously don't expect that anyone here can authoritatively answer this, since there seems to be at least some disagreement and doubt; but I wonder what the status of the question is: what the major theories are, what the evidence for them is, how big the different "camps" are?