With hindsight I am beginning to believe that Humans must have adapted to live within the cool jungle canopy of a tropical forest. As that would have been the only place "where the natural transpiration and evaporation of the leaves would have allowed Homo Sapiens a decent cooler lifestyle".
and there big toe would have moved back so that they could grasp
the tree limbs better.
living in caves was also a nice cool place where protection from the elements such as rain could be had.
over a few hundred thousand years those living in trees would have changed drastically and those living in caves would also have changed drastically.
in trees , toes move back , more body hair , mostly focused on survival , skin color changes and so on.
in caves , toes stay in place , less body hair , focused on survival but more on entertainment , skin color becomes pale ,
etc...
you can look at what we have to look at , and get an idea of
why what we have to look at looks like it looks.
.