You need a lot of eumelanin to absorb UV rays.

你需要大量真黑素来吸收紫外线。

It gets its color from two types of melanin: brown-black eumelanin and red-yellow pheomelanin.

棕黑真黑素和红黄素。

Over the course of generations, humans living at the Sun-saturated latitudes in Africa adapted to have a higher melanin production threshold and more eumelanin, giving skin a darker tone.

数代之后阳光充沛赤道地区周围非洲居民进化出了更高黑素产阈值，同时分泌出更多真黑素加深了皮肤调。

It comes in two broad varieties — eumelanin, which is responsible for the black and brown colours, and pheomelanin, which lends the skin and hair yellow to reddish hues.

黑素有两大类——真黑素和非黑素，前者使皮肤和头发呈现黑和棕，后者使皮肤和头发呈现黄和红。

There's eumelanin, which gives rise to a range of brown skin tones, as well as black, brown, and blond hair, and pheomelanin, which causes the reddish browns of freckles and red hair.

一种是真黑素，负责形成一系列棕调皮肤以及黑棕和金毛发，另一种是黑素，负责形成红棕雀斑与红毛发。