Mountain gorillas are considerably more hairy than their lowland cousins.
The evolution of sweat glands:
So, you are correct that there is no chicken-and-egg situation - because this was not a case of one trait evolving before another. The whole suite of ‘human’ features (trending towards less hair; larger brains; bipedal stance; increased endurance; changing skull shape; etc.) likely evolved in concert - which is, again, exactly what we would expect to see for a neotenous origin for humans. None of these traits were necessarily selected for in and of themselves.
Not a Just-So story, but rather a predictable result for an evolutionary pathway.
Not bipedal stance. That’s neither neotenous nor contemporaneous with the other traits you listed. We don’t know about the hair, of course, but our ancestors were bipedal long before brain expansion shows up in the fossil record.
My point being, we can speculate all we want, and point to evidence of A or B or C, and analogies to D, but there is no way to know for sure the facts of evolution.
The process of evolution works to emphasize and select for desirable traits, sometimes to the point where they are extreme and exagerrated versions of the original attributes. Neotogeny accounts for one mechanism by which traits can emerge. Something else - selective breeding, basically - encourages it to become a common or dominant trait.
Again speculation, but current thought is that we evolved from primates that emerged from the trees occasionally to gather food on the plain. As this became more and more of the activity of this creature, this selected for bipedalism; the best compromise between being able to walk on the ground (possibly carrying things) and also climb trees. We see a bit of this activity in other primates.
As bipedalism becomes a more critical proportion of the creature’s activity, then better adaption becomes critical - i.e. the guy that can run faster than his late buddies is the one who makes it back to the trees ahead of the lions. the more often and longer distance you have to do this, the more the selection for simpler, easier bipedal bone and musculature.
Not really. That was the “current thought” about 30 years ago.
Current thought is that we’re not really sure what was driving bipedalism because we don’t really know where it emerged. We keep finding evidence pushing that date back further in time, and not necessarily in areas with open plains.
There arguably are several such technologies.
Contrary to some of the suggestions in this thread, we don’t know why or when humans evolved to have mostly furless skin, nor do we know if that came before, during, or after the development of clothing. However, we do know that survival in areas that have winters is dependent on the use of clothing (or heated buildings).
The use of fire and other food preparation technologies was probably important to human evolution, since cooked food is easier to digest. We’re probably dependent on that now as a species, although we can eat many foods raw.
I would add midwifery to the list (including its modern version, obstetrics). Human birth is risky without assistance, preferably from a skilled helper.
It seems odd to consider them a single technology, but I would also add tools generally. Their use predates modern humans, and they’re required to obtain sufficient food and protect ourselves from danger.
I believe that once an animal evolves to a certain intellgence level selective breeding becomes a larger factor in how they evolve. If we take a wild animal and selectively breed it for a specific feature it will change very rapidly. Humans started cooking food so no longer were only disease resistant humans available to breed. Same with hair, less hair may have been more attractive or possibly gone hand in hand with a gene for higher intelligence. I will very often see in dog breeding physical features that will reflect a high percentage of a very specific behavioral trait. Evolution likely stopped being much of a factor in humans 100,000 years ago or more.
Not sure what that really means, but I doubt it’s true in any way I can parse it.
Well, yeah. That’s the purpose of selective breeding.
Not necessarily. Taking care of sick or injured can be done w/o cooking.
No, that’s not correct.
John, look at domestic dogs as opposed to their wild cousins which have barely changed over the years. Humans have selectively bred dogs just as we have selectively bred to one another for specific traits.
If we started eating raw carrion a good portion of us would die off. The ones that did not die off would have a gene more resisitant. Once we started cooking food the resistant strains no longer had any reason to dominate geneticaly.
A few years back a russian fur farm did an experiemnt with foxes. They selected only for domesticity. Within 5 generation you could no longer recognise these animals as foxes. They were fox like, but not really foxes anymore.
No, we have not “selectively bred” to one another in the way we have selectively bred dogs.
People eat raw meat all the time.
Yes, most of us know about those experiments. They have nothing to do with human mating patterns.