That's a specific case of the general problem, which is that humans are changing our environment much more quickly than we can adapt to it.

JS

If you can point to reliable evidence of human occupation of the Americas at 250 KYA, you'll overturn the entire field of archaeology.  Even the most aggressive interpretation of sites like Pedra Furada only goes back perhaps 48 KYA -- and those interpretations are both doubtful and hotly contested.  The earliest uncontested occupation of the Americas is about 14,800 BP at Monte Verde.

Frankly, I find assertions of high-tech in layers where people are chipping stone points to be utter bunk.  All the "mysteries" of how the pyramids or Stonehenge were built turn out to be lots and lots of people rolling things around on logs and understanding the principle of leverage.  My mind isn't closed -- but there's a very large burden of proof to meet.

JS

Uhm, we were. There is strong evidence that Man had been on the Earth as h. sapiens 300 mya. There are ruins in Africa that support this hypothesis, as well as digs in North America (Mexico) that have tools dating to abt 250 mya. There have also been some anomalous artifacts that turn up every now and then that stumps science. They aren't in the right strata, in fact they are in older strata than they are supposed to be. We had a very high degree of technology then, perhaps ST: TNG tech. The Mahabarata and the other Rig Vedas say we have been here for longer than Paleo-anthropologists say we have.

Typically, I don't know what the impetus was that drove us to till the ground and to start Agriculture from a Paleo-Anthropological perspective. The reason why has not been explained by Scientists, they can only give dates. However, there is a reason why. Were we meant to eat seeds? Certainly not, not at the degree it's been pushed into our heads since school (the food pyramid is all wrong).

I don't find any compelling evidence that we were "created" in any meaningful sense of the term, and quite a bit of evidence to the contrary.  All the "but you haven't found the missing link!" canards have been definitively put to rest by finds like Ardipithecus and Orrorin.

That being said, you're welcome to take the dietary information from my other articles and discard the anthropology.  However, I have no interest in debating established scientific fact.

JS

Very interesting...and delicious, I'm sure!

It's no problem to eat bone marrow raw, so I don't think fire is necessary: you can just smash the bone open and dig in.  However, you can boil bones in water to extract otherwise-unavailable fat out of the extracellular matrix...the Plains Indians did that with the bison they killed. 

Unfortunately the boiling technique was hot rocks dropped into a pit lined with bison skin, which doesn't fossilize, so we don't know for how long this technique was used.

JS

I don't know whether early birth was part of the neoteny package or not...big heads are definitely part of it, though.

anand:

That's how you know you're doing science: there isn't already a paper (or body of work) out there that answers all your questions!

JS

Good point. Dolphins might have a larger capacity for storing proteins directly, so that they don't need to convert as much protein to glucose.

Or they may eat small fishes constantly. That way they don't need to store much. But this rule would apply more to blue whales, which eat very small animals.

Unfortunately I don't know much about their anatomy or their energy utilization :-(.

Gorillas, chimpanzees, bonobos, and human hunter-gatherers all have approximately four-year interbirth intervals.  Having more than 5-6 offspring is a primarily Neolithic behavior, because it's only made possible by sedentism.  (If you're a hunter-gatherer mother, you can only realistically carry around one small child at a time.  H-G mothers nurse for several years vs. the one year or less common with agriculturalists.)

Also, none of the great apes have seasonal estrus, though it isn't concealed to the degree it is in humans.

However, you are correct AFAIK that human babies are indeed 'premature' (helpless for longer than chimp/gorilla babies), most likely because it's difficult to fit that big head through the hips.  Thus the flared hips of the human female.

JS

Isn't that human evolution not just favored increased brain size but also better ability to reproduce? May be it was easier to increase brain size then to become numerous. It might be evolution complexity involved between the two choices that favored increased brain size.

Oh, I had no idea. That makes sense. I knew there had to be an (wacky) explanation behind it all 🙂