Fossils of possible new human species found in China

[AquaEyes]

One problem with that, as I see it, is that while the initial explorers may be well-intentioned, their inroads into unspoiled areas creates an entry for greedy, self-interested people who will exploit and ravage the environment and its denizens for their own gain. The Amazon rainforest and many other such regions are currently being openly stripped of their resources by poachers and rogue "entrepreneurs" bent on extracting what they can, with no regard for what they are destroying.

I agree, but in terms of conservation, it's harder to set aside an area as being "hands-off" for development if no one ever went in and documented what was there and deemed it worth saving. But yes, at the same time, it does open up the area for others to come in.

 

[AllTheseCreatures]

Cool link, thanks for posting that!

 

[GardenerGal]

That's just the thing, AE: Who are we (humans) to be so qualified to assess a "value" to unspoiled parts of the planet, and to determine whether they are "worth saving"? Are we so arrogant that we believe it is our purview? Poachers and rogue pirates already have done so -- the cash value to them. Personally, I say "hands off," and shoot to kill when the rainforest pirates try to enter to strip the natural world of its beauty in order to line their pockets.

Ooo. Did I say that with my "outside voice"?

I agree, but in terms of conservation, it's harder to set aside an area as being "hands-off" for development if no one ever went in and documented what was there and deemed it worth saving. But yes, at the same time, it does open up the area for others to come in.

 

[EweSheep]

I often wondered how the earliest man evolved from the division of races. Black, white, yellow, red, and everything in between. Someone told me that the black human race was evolved from the branch of apes, so therefore, the black race is very close than the white race. I find it hard to believe which I believe it was created because of the origin, location and evironmental issues that cause the darker skinned race to become more whiter in generations to come.

How did Lucy and related families come into play in the homo sapien family tree?

 

[galanie]

All good questions but what I read is that the hotter the weather, the darker the skin. This being because melanin, the pigment that darkens it, protects the skin against sun damage. So the colder climates have light skinned people because they didn't need the melanin. We are all, after all, the same race. We apply "race" to different skin colors but in fact, we are all the same race.

 

[chickened]

What about eskimos? They are pretty dark skinned.

All good questions but what I read is that the hotter the weather, the darker the skin. This being because melanin, the pigment that darkens it, protects the skin against sun damage. So the colder climates have light skinned people because they didn't need the melanin. We are all, after all, the same race. We apply "race" to different skin colors but in fact, we are all the same race.

 

[chickened]

That is very interesting because in the animal kingdom creatures without light (cave dwellers) actually lighten over time and some have no eyes or if they do they are small and not used like a mole. Blond hair and blue eyes are a trait of Scandinavians but Eskimos kind of distort that theory.

I often wondered how the earliest man evolved from the division of races. Black, white, yellow, red, and everything in between. Someone told me that the black human race was evolved from the branch of apes, so therefore, the black race is very close than the white race. I find it hard to believe which I believe it was created because of the origin, location and evironmental issues that cause the darker skinned race to become more whiter in generations to come.

How did Lucy and related families come into play in the homo sapien family tree?

 

[GardenerGal]

Animals living where there is a lot of snow and ice, with sun's rays bouncing off the surface, have several ways of protecting themselves from the light radiation -- one, is to have melanin to absorb the radiation and keep it from getting deeper into the body; another is to have thick, inpenetrable fur, and a third is to have a reflective surface that can bounce away the rays (white, reflective fur such as polar bears').

Eskimos/Inuit may be dark for a couple of reasons. One, because in the Arctic, during the summer the sun is shining 24/7 even late at night. Two, because snow and ice reflect sun rays and intensify exposure. It's not the visible light itself, but the ultraviolet rays (UVA and UVB) that affect the skin.

Interesting about polar bears: they have white fur, but dark skin. I suspect that the fur likely evolved gradually long after the dark skin, as those with the mutation toward increasingly white fur had an advantage in a snowy landscape, concealing themselves from their prey.

 

[AquaEyes]

All available evidence suggests that humans evolved in Africa, and from a small population, grew and expanded to other areas of the world in a series of migrations out of Africa. When populations were subject to the rigors of the environment into which they lived, some phenotypes were more advantageous than others -- for example, as UV intensity decreased as they moved further from the equator, mutations resulting in lighter skin conferred better survivability and reproductive output for those individuals who possessed them.

Populations remaining in Africa continued to change through this time -- so it is incorrect to say that some populations evolved "more" than others. Based on genetic research of existing populations across the globe, the San people of southern Africa are believed to represent the earliest separation from the rest, and these people show a collection of traits that one could easily imagine being morphed with a few genetic changes into the variety found among people of the world today. Their language is also rather distinct from most others, providing further evidence of an early split.

However, as people have continued to move around and intermarry, there has not been enough time for any population to be totally reproductively isolated from others to allow for enough genetic differences to be properly classified into "races." While differences can be found between individuals selected at widely disparate points across the world, these differences become clinal as one progresses across areas between these points.

And as far as total number of genetic differences, there is more variation found between two individuals of any one "race" than are differences between any two "races." In other words, if we say that the number of genes that differ solely to cause a man from China to look different from a man from Spain is 20 (hypothetically), the number of genes that differ between any two randomly selected men from China (or between any two randomly selected men from Spain) would be something like 2,000. This would happen because of migration of populations and individuals, intermarriage, no concept of "border zones", and natural selection favoring those few genes that would result in the "typical Chinese phenotype" (as if there was just one) for people living in China.

Because of our intelligence, there are no natural boundaries which have not been crossed which would otherwise have separated our species into reproductively isolated populations -- something necessary for genetic variation to accumulate between populations to the degree required for the biological concept of "races" to be satisfied. There would need to be something like a river, or mountain range, or some other such natural boundary which found one "race" on one side, and another "race" on the other. But because humans recognize each other as potential mates regardless of "race", and because we are not completely prevented from crossing such natural features, such divisions have not occurred.

 

[AquaEyes]

What about eskimos? They are pretty dark skinned.

Native populations among Alaska and surrounding regions descent from populations that migrated from Mongolia and surrounding regions. These individuals tended to have darker skin because it was favored in the original environment, but it is thought that since the time of migration into the Alaska region was relatively recent (in geologic terms), there wasn't enough time for selection to favor individuals with lighter skin. Or, it's also possible that through their culture, they negated that selection by satisfying their vitamin D requirement through their food choices. Their traditional inclusion of raw whale blubber similarly satisfied their requirement for vitamin C, which, considering their lack of access to produce during the winter months, would have otherwise prevented them from surviving through the winter.