[shunyadragon]

</span><blockquote><span class="smallfont">Quote:</span><hr size="1" />Originally Posted by (orgaelin,)
Hi, I'm new here but I'm really looking forward to some great debates. This is my first post...

I've been pondering our relative hairlessness and large genitalia (relative to other mammals, though it may not apply to some of you quite so much;-) and considering a potential explanation.

It seems the most obvious thing that happens when you take away the hair which covered our more primitive ancestors is that our sex becomes far easier to identify. Our breasts, buttocks and genitalia (all seen as sexual organs in one way or another (read "Prehistory of Sex, The", by Timothy Taylor)) are all enlarged relative to other primates, again making our gender much more readily identifiable.

Why?

Can anyone think of an evolutionarily significant benefit of having our gender made so obviously visible?<hr size="1" /></blockquote><span class='postcolor'>

Hairlessness is an interesting puzzle in evolution, because there seems to be no direct benifit for hairlessness, except that it is commonly found in more intelligent mammals that have a long gestation period like elephants, pigs and sea mammals. Hairlessness may be a consequence of a prolonged fetal development to alow for the development of the human brain. Prolonged fetal development and hairlessness are also associated with the increased need for nurturing. The human development is unique because the infant is born totally helpless and physical development is slow. Where many new born mammals are up and walking and relatively mobile in minutes. The other primates represent intermediate stages of this prolonged fetal development. Humans represent the longest prolonged fetal development and nurturing period of any mammal.

In the evolutionary picture the human evolution took the route of the more intelligent larger specialized brain. In exchange they gave up hair, speed, size and became relatively weak in comparison to other mammmals. The newly acquired intelligence more than compensated for the loose. Humans developed speach, clothing, tools and weapons.