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.
Answer:
The Galapagos cormorant has vestigial wings that don't help it to fly or swim, though the birds still dry them off in the sun after they get wet, just as if they would if they still could use them to fly. This species diverged into a flightless bird about 2 million years ago.
Explanation:
All energy Earth receives from the sun is turned into energy for other things like food and nutrients.<span />
Only a fraction of the energy<span> available at one trophic </span>level<span>is </span>transferred to the next<span> trophic </span>level<span>; the fractions can vary between 1-15%, with an average value of 10%. Typically the numbers and biomass of organisms decreases as one ascends the </span>food chain<span>.</span>
