There’s a new article out in Science tracing the splits in gut flora. It looks as if the gut bacteria in chimpanzees split with those in humans 5.3 million years: doesn’t quite match our genetic estimates based on Human/chimp autosomal DNA differences, but it’s in the ball park. They estimate the human-gorilla split at 15.6 million year ago, but that can’t be right: we know that gorillas split off just a bit before the human-chimp split. Perhaps gorilla diet changed drastically, and maybe they picked up new bacteria from some other species.

Different populations of modern humans apparently have pretty different microbiomes. The gut bacteria from people in Malawi appear to have diverged 1.7 million years ago from those in Europeans (people from Connecticut). That is surely too old to be a consequence of modern humans’ trek out of Africa: it looks as if AMH, after leaving Africa, picked up gut flora from archaic sapiens like Neanderthals and Denisovans and dwarves.

Microbiomes are trendy. We know that fecal transplants can cure C difficile (pseudomembranous colitis) lickety-split: they might help with Crohn’s disease and ulcerative colitis. Some researchers think the microbiome has something to do with the initiation of multiple sclerosis. Others suspect that it may play a role regulating how people think and feel – in particular, mood disorders. Autism has been mentioned.

So.. Poop matters: it certainly can affect health, and it may influence brain function. People from sub-Saharan have divergent poop, or you could say that Eurasians do. Are there differences in brain function between sub-Saharan Africans and Eurasians? Sure: Africans do poorly on IQ tests and in academic subjects. They have significant higher rates of schizophrenia, higher murder rates, etc.

Maybe it’s the poop. It’s worth checking out. Perhaps the fault lies not in our stars, or our genes, but in our stool.

Already, eager experimenters – paleos on stilts – are trying to dramatically modulate their internal flora.

“AS THE SUN set over Lake Eyasi in Tanzania, nearly thirty minutes had passed since I had inserted a turkey baster into my bum and injected the feces of a Hadza man – a member of one of the last remaining hunter-gatherers tribes in the world – into the nether regions of my distal colon. I struggled to keep my legs in the air with my toes pointing towards what I thought was the faint outline of the Southern Cross rising in the evening sky. With my hands under my hips – and butt perched against a large rock for support – I peddled an imaginary upside down bicycle in the air to pass the time as I struggled to make sure my new gut ecosystem stayed put inside me.”

The problem, he’s likely running this in the wrong direction, unless he’s just gotten a high-paying job as a professional hunter-gatherer. Generally, we want to better adapt people to key features of industrial civilization, like eating Chicago-style pizza while doing calculus homework, rather than shooting pizened arrows at gazelles.

Judging from Common Core, the standard approach with a potentially gap-closing panacea is to impose it on the entire country without running any careful, small-scale tests. Fortunately, due to Sturgeon’s Law, we don’t ever have to worry about running out of raw material.

Now, I know what you’re thinking. There’s a potential show-stopper

The question is – are blacks in the mood to take any more shit from the Man?