Yes I know about that. The Toba eruption was one suggested cause. Not sure on the current consensus but I know some people were questioning whether the bottleneck was real and when, if ever, it happened. The point is though that even if you allow for this it doesn't get around my objection.
Ring species, if you're not familiar with the term, are species that although distinct are capable of interbreeding with their neighbouring species and sometimes do this in the wild. However if you take the example of species of gulls living around the edges of an ocean (which was one of the earliest recorded demonstrations of the principle) you get a situation where by the time you come full circle the species are so different that they cannot and do not interbreed, even though for the rest of the circuit there is a chain of species that can and do sometimes interbreed.
This is what I meant about the theory of multiregional evolution of humans over millions of years in different climates. I would expect some greater genetic differences than what we see in practice. Throwing in a bottleneck circa 100,000 years BP does nothing to change this and indeed may well exacerbate the effect, because then you would have separated and divergent populations
each being reduced to a smaller gene pool and regenerating from that basis, which would (I think) tend to result in greater differences between populations.
So as I said, in the absence of strong evidence for the multiregional theory I tend to think the "out of Africa fairly recently in one lump" theory is more likely.
No I disagree. I'm pretty sure if a mathematical model was done on the energy lost in the cold compared to energy to find water/food in a warm climate that overall living in a cold climate would be harsher. Can't find such a study,
but here is a tin pot one.
I didn't say "warm climate". I said some of the harshest deserts on Earth. IOW, bloody hot and dry climates with extremely limited resources. These climates can be lethal very quickly.
I disagree. In the short term nutrition definitely helps. But in the long run, over generations, those who need to *think* will be the one who are more *practical* and so *survive*.
So basically, why are polar bears not on the moon yet? Well, they have thick coats. They just happen to evolved that way. Camels just happened to form humps to help them survive the scarce dessert conditions ... and it just so happened (with the 100 different mutations per person) that humans evolved a mind in order to survive the cold (I think).
Possibly, but not certainly. Bear in mind that before you can grow a large brain you need the resources to run it. If these are not available then it will never happen, regardless of how useful it might be in theory. One thing that some people don't realise is that evolution does not necessarily lead to optimum solutions. All it leads to is solutions that work well enough for the moment. Sometimes it doesn't even lead to that, which is why extinctions are so commonplace.
So, if you do have the resources to grow a large brain then you don't just need to use it to hunt mammoths or whatever. You can also use it to entertain and enthrall your companions. This may well help to attract a mate, in which case the genes for that brain will tend to become self-perpetuating. In other words, it could have started off not because of hunting during an ice age but simply because stupid people aren't as interesting. Hominid brains were increasing in size before any of them left Africa so it aint all down to hunting mammoths in Asia.
Topic: High IQ turns academics into atheists