Here we begin to see the evolution of the beautiful sepia rainbow that now characterizes all of humanity. So what did he make of all this. And when he was in his 20s he embarked upon a remarkable voyage on the ship the Beagle.
Humans have been on the move for a long time. Much of this must have taken place long before they had acquired enough brains to be prejudiced about it. Only — generations ago, the ancestors of most people living today likely also resided in a different place and had a different skin color.
So lets all wish for his great health, and his awareness of his own skin pigmentation. Genetic evidence also supports this notion, demonstrating that around 1. The incrementally cooler colors -- blues, greens, yellows, and finally grays -- indicate areas of much lower ultraviolet radiation.
There is a correlation between the geographic distribution of UV radiation UVR and the distribution of skin pigmentation around the world. And the observations that he made on that epic journey were to be eventually distilled into his wonderful book, "On the Origin of Species," published years ago.
This hypothesis is not consistent with the evidence that most of the hominid evolution took place in savanna environment and not in tropical rainforests. And during the course of that voyage, he saw remarkable things: Applause How wonderful is that.
It is reasonable to assume, then, that we humans have this molecule not because it makes us smarter but primarily because it helps us survive a variety of environmental conditions.
And for many decades now there have been a series of TOMS satellites that have collected data about the radiation of the Earth's surface. And he resembles, very closely, people with moderate levels of pigmentation who live in southern Africa, or Southeast Asia.
Areas that have higher amounts of UVR have darker-skinned populations, generally located nearer the equator. This is remarkable given that the number of polymorphisms for almost all genes in the human gene pool is greater in African samples than in any other geographic region.
And he resembles, very closely, people with moderate levels of pigmentation who live in southern Africa, or Southeast Asia. The native people of Bougainville, Papua New Guinea, have some of the darkest skin pigmentation in the world.
In those early days of our evolution, looking at the equator, we were bombarded by high levels of ultraviolet radiation. And not all these moves were voluntary. Evolutionary pigmentation of the skin was caused by ultraviolet radiation of the sun. Early members of the genus Homo and ancestral Homo sapiens evolved darkly pigmented skin, rich in the natural sunscreen eumelanin, as protection against the manifold negative effects of intense UVR on the skin and body [ 23 ].
A few million years of evolution later, early humans had sparse body hair and more than 2 million sweat glands in their body. They also run the risk of vitamin D deficiency, if they have desk jobs, like that guy.
This is not a problem near the equator; however, it can be a problem at higher latitudes. Epidemiologists and doctors have been very good about telling us about protecting our skin. I think, were he able to look at the evidence we have today, he would understand it.
Here, we briefly review the current state of knowledge on the relationship between skin pigmentation, UVR exposure, migration history, lifestyle and disease risk.
And yet he rejected the idea that human skin pigmentation was related to the climate.
This is the result of human evolution which contributed to variable melanin content in the skin to adapt to certain environments. Photodegration occurs when melanin absorbs photons.
And when he was in his 20s he embarked upon a remarkable voyage on the ship the Beagle. What they haven't been so good about instructing people is the problem of darkly pigmented people living in high latitude areas, or working inside all the time.
Where it protected the body against the degradations of ultraviolet radiation, the destruction, or damage to DNA, and the breakdown of a very important molecule called folate, which helps to fuel cell production, and reproduction in the body.
You, you can teach it. Applause This man is significant for a whole host of reasons.
He said, "Of all the differences between the races of men, the color of the skin is the most conspicuous and one of the best marked. And he was somewhat interested in the pattern of skin color. You can touch it. Mar 19, · Human skin pigmentation evolved as a compromise between the conflicting physiological demands of protection against the deleterious effects of ultraviolet radiation For people with darkly pigmented skin, these ‘vitamin D safe zones’ are smaller and shifted towards the equator because of the efficacious.
Jun 21, · Evolutionarily, each of us is African; the first people had darkly pigmented skin and were thus well-adapted to handle the high levels of UVR (ultraviolet radiation) in equatorial regions.
SKIN I. INTRODUCTION Skin, outer body covering of an turnonepoundintoonemillion.com term skin is commonly used to describe the body covering of any animal but technically refers only to the body covering of vertebrates (animals that have a backbone).
The skin has the same basic structure in all vertebrates, including fish, reptiles, birds, and humans and other mammals.
This article focuses primarily on human s. In general, people living close to the equator are highly darkly pigmented, and those living near the poles are generally very lightly pigmented.
The rest of humanity shows a high degree of skin color variation between these two extremes, generally correlating with UV exposure.
Less melanin in their skin, so there is less protection against ultraviolet radiation. Melanin is a pigment produced by melanocytes in the bottom cell layer of the epidermis.
Melanin production is increased on sun exposure, leading to higher levels which help prevent cellular damage due to UV radiation. Melanin, the skin's brown pigment, is a natural sunscreen that protects tropical peoples from the many harmful effects of ultraviolet (UV) rays.
UV rays can, for example, strip away folic acid, a nutrient essential to the development of healthy fetuses.Skin ultraviolet and darkly pigmented people