White Sclera

Nope, educate yourself.
en.m.wikipedia.org/wiki/Tit_for_tat

Random mutation, became highly 'successful' in humans because it makes communication without speaking easier, for war, hunting, etc.

Gorillas aren't known to hunt or commit wars, but occasionally communicate with eye gestures. Probably more common and may eventually become common place for chimps as they proceed to show further hunting and warlike behaviour (making the mutation more beneficial for communication).

Anything else?

Any thoughts on when this mutation started spreading? The australopithecines, or just homo?

The mutation itself probably has been around for a very long time, possibly even before Hominidae.

Though, it didn't start to become a dominant trait until the correct behaviours for it to become beneficial arose.

Considering cooperation would be a must in an open environment, seems like it may have begun to spread in the australopithecines and was carried to both homo and paranthropus.

anyone watched that new documentary "Rise of the Warrior Apes"?

youtube.com/watch?v=dQn1-mLkIHw

hasn't been released in my country unfortunately

Certainly as they became gradually more sociable evolutionary pressures involving communication, or the lack thereof would have made having this mutation more beneficial.

For instance, stalking dangerous pray or enemies without giving away position with audible communication.

Seems more likely to be watching out for enemies and predators, considering they were most likely opportunistic as opposed to predatory.

Regardless, the beneficial nature boils down to adding another layer to the ability to communicate successfully, in this case, where situations demand silence.

Gorillas and chimps both regard eye contact as a form of aggression.

Having dark sclera is advantageous as it allows these animals to look at one another without it being obvious that they are doing so, and thus helps them avoid starting a fight.

Having white sclera would result in that individual being singled out more often and possibly ostracized, lowering the chances that they will mate successfully and thus applying a selective pressure against white sclera in the general population.

As the ancestors to humans became less aggressive towards one another and start to actively develop communication, not only did the selection pressure against white sclera go away, it may have actually reversed. Knowing that the person you're talking to is looking at you strengthens the communication link, making that person more sociable and more likely to mate successfully and pass on the white sclera mutation.

A similar process made us develop more expressive faces and got rid of the mental link between showing teeth and aggression. Smile at a human baby and they'll probably trust you; smile at a silverback gorilla and it will probably try to maul you, as it sees you as a very aggressive and disrespectful enemy.

Humans still bare their teeth as a sign of aggression though.

>evolutionary psychology
KYS my man.

We also smile.

No ape expressions that include the showing of teeth are associated with positive attitudes, except for in humans.

>psychology is determined by the brain
>the brain is subject to evolution
>therefore psychology is also subject to evolution

get out and take your tabla rosa shit with you, nigger

It does have a lot of problems, though.
evoanth.net/?s=Psychology

check out this rare chimp
albino with white sclera and heterochromia

We'll be seeing him in the next X-Men movie.
>X-Men: Jungle Class

What are those clickbait titles?

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contact lens