Darker skin is more prevalent in high-UV areas. Dr. Nina Jablonski proposed a hypothesis to explain the selective pressure for d
arker skin in these environments. On what evidence did she base this hypothesis? Darker skin is more prevalent in high-UV areas. Dr. Nina Jablonski proposed a hypothesis to explain the selective pressure for darker skin in these environments. On what evidence did she base this hypothesis? the melanin in darkly pigmented skin protects circulating folate from being destroyed by UV radiation, and folate is important in human reproduction the melanin in darkly pigmented skin protects DNA from UV radiation, and UV radiation can cause skin cancer people of African descent all have the same version of the MC1R gene, indicating that this gene was under selection she discovered that people of African descent have less folate circulating in their blood and that folate is important for human reproduction
The answer is; the melanin in darkly pigmented skin protects DNA from UV radiation, and UV radiation can cause skin cancer
In Africa, due to its equatorial latitude location, receives direct sunlight at more or less 90 degrees most of the year. These highly concentrated rays increase the UV radiation exposure that can cause damage to cell DNA. Selection pressure, therefore, favored individuals with high melanin concentrations that protect against UV. Therefore population evolved towards high melanin densities in the skin.
<span>I think that the best initial approach to the client by the nurse would be to comfort and first assure the client that she's not there to hurt or harm the client in any way and that no one is judging (s)he and most important that this recommendation is only for the better and to help the client.</span>
The Coriolis Effect can be seen in action in the general circulation of the atmosphere. The winds at all latitudes to the north of 0° deflect to the right of their intended path in the Northern Hemisphere. The Coriolis Effect does not impact the wind speed, only the wind direction.
