Vizeet:

Absolutely: human brains have shrunk by roughly 10% since the advent of agriculture.

Re: projectile weapons, even if the Neandertals picked up the technology from Homo sapiens sapiens, their physical advantage of far greater strength would have been completely neutralized -- and, in fact, their greater bulk (and, presumably, greater calorie requirement) would have become a disadvantage.

Matthew:

I'm glad you find my writing interesting, and I hope you enjoy TGC!  Do stick around.

Luke:

Thank you.  I'll be back to this subject soon.

JS

Lauren:

That would be the "Aquatic ape theory", which just came up in the discussion for Part III.  Pardon me for quoting myself:

"I don't see the evidence that [AAT] is true. There's no evidence that Ardipithecus or any other transitional bipedal hominins were aquatic in any way, either in behavior or in diet — and the fact that the transition to bipedalism preceded the increase in hominin brain size is evidence against it."

It's very important to remember that when Morgan wrote her books on AAT, there was no fossil record of the hominin transition to bipedalism -- so AAT was a plausible (though heterodox) alternative.  The transitional fossils between the chimp-human divergence and the bipedal A. afarensis (Orrorin, Ardipithecus) were found very recently, and only publicized in the last few years!  So it's only in retrospect that we can dismiss AAT.

(This is the problem with anthropology books...with so many important discoveries coming to light so recently, most printed matter is already out of date!)

JS

Kenneth:

Thank you!  There's something viscerally satisfying about eating meat on the bone, outdoors...because we've been doing it for millions of years.

JS

jane:

Gravlax is a great way to get people who "don't eat raw meat/fish" to eat raw fish!  (Here's the recipe.)  

No, I've never gone 100% raw for any significant period of time, though I've done it for perhaps two days.  Not intentionally, though...usually because I'm on the road and eating gravlax and salads out of a cooler!

JS

roger:

First, I think you mean 900-1500cc, not 2500cc.

Second, intelligence in the modern era is roughly 1/2 dependent on cultural transmission (the probable source of the "Flynn effect") and only 1/2 on innate capability -- so it's risky to extrapolate from modern distributions to the Paleolithic, where cultural differences were much smaller and innate intelligence a much greater factor.

Third, you'll recall that Homo floresiensis was necessarily descended from either H. erectus or H. sapiens, meaning that its primitive stone toolkit was necessarily invented by ancestors with larger brains typical of hominins of the time.  Chimpanzees can be taught to flake Oldowan stone tools, among other complicated behaviors...but there's no evidence that they've ever managed to invent them on their own.

While I don't think that cephalic ratio explains all of human intelligence, it's clear that larger brains are more energetically expensive than smaller brains -- so there must have been some reason that they were selected for despite this handicap.  If you don't think larger brains were necessary for the development of intelligence, it's your responsibility to come up with an alternative explanation for them!

JS

roger:

I don't think Homo heidelbergensis and the Neandertals were dim-witted: try surviving in ice-age Europe without the benefit of modern technology -- or any technology at all beyond sharp rocks you made yourself.

In fact, since all the things we think of as "culture" post-date the emergence of anatomically modern humans, it's clear that surviving as a hunter-gatherer had to be very mentally demanding: otherwise our ancestors wouldn't have developed these big brains in the first place!  

Yes, there's a great deal of variation in modern brain size...but the fact that it's decreased over 10% since the invention of agriculture should tell us something.  Also, culture and education creates roughly half of what we think of as "intelligence"...but I do note a distinct lack of genius proportionate dwarves in the historical record.  And it turns out that Stephen Jay Gould's The Mismeasure of Man was a deliberate fraud.  So while I believe that enough other confounding factors exist that cranial capacity doesn't tell us much about the capabilities of any individual modern human, I think it's reasonable to use its average as a proxy for relative intelligence of hominins in archaeological time.

JS

roger:

We're still in the Pliocene at this point.  The so-called "Great Leap Forward" post-dates anatomically modern humans, and is still several million years in the future.

JS