(None of this is intended to be racist and shouldnt be taken as such, its science and quite interesting at that!)

First lets start off by saying that there are 4 Major *Races* of Human on Earth (not just one with some genetic differences as most believe.) These are...

A.) Asian

B.) Black

C.) Caucasian

D.) New World Indians

(heh alphebetical)

Every other skin color, or "Human Race" is known to be a genetic mixture between these four.  But lets get on to some of the distinct and quite interesting differences between the skin of the Human Races.  (Unfortunatly there has been very little research done on the Skin of American Indians as of yet due to their general, and understandable reluctance to allow such studies)

1.) Black skin has larger Melanosome cells which allows them to absorb considerably more sunlight and radiation than the other races.

2.) Black skin also has considerably higher electrical resistance than its cousins.

3.) Black skin has many more and larger Fibroblasts than White Skin which makes it considerably easier to Scar the skin from simple cuts.

4.) Black Skin is generally thicker than the other races

5.) Asian & Black Skin have Thicker and more Compact Dermis than white skin - which is why Older White people (women in particular) hae FAR more wrinkles around their bodies.

6.)  Black Skin actually shed much faster than the others.

7.) Asian Skin loses 20% less water than Black Skin which loses 50% less water than White Skin.  This means That White Skin can remain MUCH cooler than its counterparts at high temperature, BUT it also means White people get Dehydrated MUCH MUCH faster than everyone else...by a long shot.

8.) White Skin cells regenerate 20% fast than Black skin and 10% faster than Asian skin.

9.) White and Asian skin are equally flexible, and each is far more flexiable than Black Skin.

10.) Asian Skin can take more pressure from sharp objects before breaking open.

*more soon*

"4 major species of humans"

What is this? Skyrim

ifNot sure what your implying here :P

If your implying that im calling Mexians lesser humans you are wrong lol.

 It's the same as Dogs and Cats

We have thousands of different breeds of dogs and cats but most of them are mixtures of other breeds.  Wolves are on of the Major Dogs races and the Big Cats are the Major cat races.  House Cats and Dogs are the result of inter-extra species breeding.  The same goes for we Humans :P

Of course this all relies on the belief in Evolution, Humans from different areas of the world evolved from different *extinct* breeds of Monkey/Apes ect ect.

Haha I loled.

Btw Bruce Lee is a dragon and my skin is strong enough to bath in melting lava and take 1000000 arrows to the nee.

knee.

All we wanted to know is how different skin behave when it comes down to sex!

XD no not at all. I just found that funny since a Human would be a species, and what you're describing are races, not different species.

And btw, each race didn't evolve from different animals, all races share one common ancestor, which is humans common ancestor, it's just that Humans themselves have gradually adapted to different environments, thus creating variety in the human species.

It's the fact you used the term different "species of human". Species by definition can't successfully mate and have viable offspring which all humans can. What you're effectively describing are different "breeds" of human... or rather different ethnicities.

Big cats and domestic cats are different species btw. Hell, lions and tigers are different species. Humans are one.