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Thursday, January 24, 2008

Vegetarians are able to produce kids with brains

Archaeologist John Speth gave a very interesting Brown Bag presentation today entitled, "How important were large mammals, animal protein, and DHA in hominin evolution? 'Paleoanthropology still ain't heard the news'."

In it, he discussed why the aquatic theory that human evolution was driven by a need for DHA fatty acids for brain function was probably wrong. His reasoning was that if humans needed to consume DHA (which is found in seafoods) to get enough of it, then populations that didn't eat seafood would not have "proper" brains, which is of course not what is observed. This is where the title-quote about vegetarians comes in. It turns out many of the previous studies on humans producing DHA were done solely on males, and it wasn't until recently that females were studied as well. It turns out females are more efficient at bio-synthesizing DHA than males, and that DHA is stored in adipose tissues, which females tend to have more of.

So, does anyone know if this means I can stop buying expensive OJ with Omega-3's added in?

5 comments:

Big Chief said...

he's an archaeologist - not a paleontologist

Caroline said...

whoops.

Thayne said...

I love how this ties in with facundity.

Big Chief said...

Fecundity indeed - The most interesting part of Speth's argument is his supposition that hunting and/or scavenging played a minimal role as a nutritional source for brain size increase in hominids.

What does this say about the drive for early animal procurement behavior, which he suggests could have focused on the eating of stomach contents?
Is it social bonding? Male showboating?

Speth also highlights important biases and inadequacies within the field of archaeology, particularly that of the Old World Paleolithic:

Modern hunter-gatherers are an example of the "natural" human condition, every male wants to mount antlers on the wall, and the woman at Laetoli is still walking three steps behind the man.

Thayne said...

Great questions, big chief. I'll wager a pisafom that while hunting contributed only scant nutrients to the great cranial boom of pre-history, it was muy importante to the development of an equally important aspect of the human lineage: culture.

Hunting helped endow mankind with wonderful spacial orientation, story-telling, extensive knowledge of local flora and fauna, cooperation, language, creativity, imagination, and technological advancements.

Hunting also played a key role in strengthening the importance of social gathering, kinship, and need I remind you that for some societies (the forefathers of the Inuit spring to mind) relied heavily on meat.

And yes, male showboating played its part as well. How else were we going to impress the chicks?