Both drugs had been previously recommended for approval 14-0 by members of FDA's Anti-Infective Drugs Advisory Committee. The significance of two new antibiotics in four weeks? We've recently been averaging one antibiotic every three years.
More melanin presence in the skin makes the skin appear black, and less melanin will make the skin appear less black. White people have very little melanin synthesized by their skin. So, the color of the races is because of some difference in the quanitity of the melanin pigment in our body. That is all.
There are two different types of melanin, the pigment that allows skin to tan and that makes brown eyes brown. There is a dark, black melanin and a yellow melanin. An eye without melanin, either black or yellow will be blue. Green eyes are caused by low levels of black melanin and higher levels of the yellow melanin.