Discussion:Evolution of sentience
When Stewart first joined the group I was talking about evolution of consciousness/sentience which I define as the capability of the species to perform directed genetic engineering and I said this must've been a selectively advantageous trait. The problem (as Stewart rightly pointed out) was since there's a huge lag between the development of the capability and development of sentience, how can natural selection be operating on this trait? The answer (of course) is more obvious to me now than it was then, which is (of course) that an early form of the trait must manifest itself, like for example a an optimum height advantage of 5" might have the first selection occurring at a height of 1" or even lower (which is more likely to occur in a population than a height of 5" though both are possible). So traits can be thought of as kind of continuum. And since current homo sapiens appear to have killed off all their ancestors (which is what I believe, but the main thing is that they're not here) we don't know what intermediate forms of human-like sentience might look like between humans and chimpanzees our closing existent primate relative, but if sentience can be thought of as a continuum (of course) then chimpanzees arguably have some earlier version of it than we do (of course) and THAT might be selectively advantageous.
But that still begs the question of why it is selected for, i.e., why is it beneficial for survival and (better) propagation of genes? Presumably the ability to perform directed genetic self engineering has an early form that involves mate selection. That is, which organisms besides humans looks at their mate and goes "if I have an offspring with this mate, my genes will propagate better"? Of course mate selection occurs at a primitive level in many species but now I'm referring to something that involves, you guessed it, a "conscious" choice. The capability to actively make this choice I believe would presage sentience.
While performing genetic engineering requires a lot of other complex traits like language, opposable thumbs (perhaps), sophisticated machine/tool creation, and so on, the above simplified version of the trait doesn't. This statement then, about mate selection and choice and effect, is a testable hypothesis and we finally get down to science instead of speculation.
This is also a complex trait (of course) involving perhaps the whole brain (though some regions seem to be more responsible than others).