Sorry, not in any way "racits" but the truth may well offend those who think it is:
http://www.amren.com/ar/1992/12/index.html#cover
"Race and Physical Differences
Physical differences between the races are just as striking as mental differences.
by William Robertson Boggs
Everyone recognizes race. Africans, Europeans, and Asians can be distinguished at a glance because the races differ so obviously from each other. Although the differences are popularly referred to as ?skin color,? as if this were where they began and ended, color is one of the least important ways in which the races differ.
Although many physiological differences are well established and easy to measure, they are often completely unknown to the general public. Perhaps this is because the cumulative effect of a list of physical differences can give an impression of alienness even more powerful than do assertions about mental differences.
Just as it was once universally accepted that races differ in intelligence, so the study of physical differences was once entirely respectable. Some 19th century investigators, however, hoped to find justifications for slavery and not all were good scientists. Therefore, in the revolt against ?racism,? good data from the past has been thrown out along with the bad, and the study of physical differences has languished.
The modern data now becoming available confirm many 19th century views. The best evidence suggests that races differ markedly in such things as maturation rate, brain size, bone density, susceptibility to disease, and perhaps even personality.
The races differ in skin color because of different levels of melanin production. All races have approximately the same number of melanocytes, or melanin-making cells, but they differ in how actively the cells make melanin.......
.....Color does have one physiological effect: three and a half times as much ultraviolet light from the sun passes through the skin of whites as through that of blacks. Light skin is beneficial in the northern regions where whites evolved, since ultraviolet light converts ergosterol in the body into vitamin D. Dark skin protects against the tropical sun..........
..... Adaptation to Climate
There are other racial characteristics that are obviously adaptations to the climates in which the races evolved. Many East African peoples have elongated limbs and bodies that easily dissipate heat. North Asians, on the other hand, have evolved in a cold climate. Their bodies are more squat, they have thick, dark hair, and the epicanthic fold that gives Asians almond-shaped eyes is thought to reduce glare from snow and ice. A flat nose is less exposed to cold, and the virtual absence of facial hair means that condensation from a man?s breath will not freeze on his beard and chill his face. All of these characteristics are most obvious in the Asians who live in the coldest climates.
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....... The distribution of the common blood types is different from race to race, and some rare types are unique to certain races. Only blacks have U negative blood; only whites have Vel negative or Lan negative blood. Dr. W. Laurence Marsh of the New York Blood Center justifies racial classification: ?It makes no sense to screen 100,000 whites for U negative when no U negative white person has ever been found.?
Kidneys and other organs are classified by race for similar reasons. About 20 percent of blacks are so genetically incompatible with whites that they reject organs from all white donors......"
