How did we come to be us?

[I'm Murrin]

I remember seeing a TV documentary about the "aquatic ape" hypothesis. It suggested things like our ability to hold our breath (which other apes can't do), upright walking (to hold our head above the water), and brain development were down to living on the coast and eating a seafood diet. As far as I know, though, it's not a very widely accepted theory.

[peter]

Will most certainly try to hunt this down Vraith. The 'coastal' abservation is entierly relevent in that Walter's book outlines an ongoing debate in paleoanthropological circles as to whether at one point our human ancestors literally rubbed shoulders with extinction. Some professionals apparently consider that Homo sapiens numbers were reduced to a rump of a hundred or so individuals living on the coast of South Africa, this occuring some 70,000 years ago (IIRC) - at such a level any catastrophic event or disease outbreak could have spelled the end of the whole human experiment. Though disputed by others in the field, if this is indeed the case then we are truly fortunate to have made it to here at all!

Another thing I have learned that I was totally unaware of is the almost insepparable relationship between genes and a surrounding matrix of histones that regulate their expression, the whole being known as the 'epigenome'. These histones apparently exert as much influence in the nature of heredity/gene expression as the genes themselves, to the point where genes cannot really be considered usefully in isolation. Clearly much has been learned that has passed me by in the last 25 or so years since I studied these things.

[Avatar]

Dunno about aquatic, but I think our shellfish diet as evidenced by the many shell middens uncovered is almost certain to have affected the growth and development of our brains.

--A

[peter]

Has anyone else come across this idea that longevity and brain size can be increased by living on the edge of a starvation situation? The 'brain increase' is apparently in real terms and not just as a percentage of body-wight due to loss of muscle tissue and fat. Walters gives some of the physiological details regarding increase in neurones/connections etc but it was all new stuff to me.