Expert: John Shea - 8/21/2007

Question
Hello,

I've recently been arguing with someone who is under the illusion that we didn't eat much meat in Palaeo times, and that we mostly scavenged rather than hunted. Given current isotope-ratio-testing of bones the former "theory" is easy to disprove - as for the latter "scavenger" theory, as I understand it, it's heavily biased as it falsely assumes that Neanderthals and other apemen were too stupid to be able to work out how to hunt effectively(despite current evidence showing high level of Neanderthal culture etc.) - and, of course, chimpanzees are known to hunt monkeys, for example, so this theory seems highly unlikely.
Also, as I understand it from current scientific data, scavenging primarily  for animal-food/carcasses is too prohibitive in terms of energy-costs, effort  and time, as predators almost always protect the carcass after killing their prey.

Anyway, what's your view of the scavenger theory and could you please tell me what  palaeoanthropology magazine I should subscribe to in order to learn about the latest research re the diet of Palaeolithic humans and the effects of a Palaeo-style diet on humans? It's just that most scientific studies re the Palaeolithic diet are shielded and require payments of up to 30 US dollars before I can even view the study to judge whether it's of any genuine interest to me. I would prefer it if you could point me to a UK-based magazine but any will do, if that's not available.

Answer
Dear Geoff,
The short answer is that changes in human ancestors' brain size and dentition (larger brain, smaller teeth) suggest a shift towards concentrated high-quality low bulk foods began in earnest around 1.8 Million years ago.  It is possible that some of these high-quality foods were plant foods, but meat and animal fat are more likely.  Why?  These morphological shifts persist in cold climates, like Europe and temperate Asia where plant foods are seasonally scarce (and animals are not).  Many recent human hunter-gatherers scavenge from big carnivores when possible in addition to hunting, so it is not unreasonable to see scavenging as part of early hominin meat procurement strategies.  Evidence for  evidence of highly-effective hunting (projectile weapons, nets, traps, etc.) shows up rather late in the archaeological record of our species, only consistently after around 50,000 years ago, though, so there appears to have been a long period when humans were either less effective hunters than recent hunter-gatherers (perhaps more dependent on scavenging?) or one in which their hunting strategies left less clear an archaeological record.
Bear in mind, the significance of meat and animal fat in prehistoric human diets probably varied seasonally and geographically.  Basically, it was more important during colder conditions.  Bone chemistry suggests some Neandertals (West European ones dating after 40,000 years ago) were basically carnivorous, possibly specialized predators on big grazers, like mammoth and steppe rhino, but this may not have been a shared characteristic of all Neandertals.
There are a lot of internet sources out there on this subject, just type in "Stone Age Diet" or "Paleolithic prescription".  Peter Ungar's edited book, The Evolution of the Human Diet (2007) is a good starting point, if you want the straight story from leading scholars.  Loren Cordain and S. Boyd Eaton have also written a lot on implications of paleo-diet for modern human health.  There really isn't a single journal to which you could subscribe that focuses on this issue.  Instead, try using Google Scholar to find papers on the topic and/or by scholars whose papers appear in Ungar's book.  (Full disclosure: I have a paper in this book, but it is about stone tools, which tell you very little about human diets.)
Best wishes.  Feel welcome to follow-up, if you need more assistance.
Cheers,
John Shea