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

棕黑色真黑色素和红黄色褐色素。

You need a lot of eumelanin to absorb UV rays.

你需要真黑色素来吸收紫外线。

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.

黑素有两类——真黑素和非黑素，前肤和头发呈现黑色和棕色，后肤和头发呈现黄色和红色。

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.

数代之后生活在阳光充沛赤道地区周围非洲居民进化出了更高黑色素产生阈值，同时分泌出更多真黑素加深了肤色调。

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，负责形成一系列棕色调肤以及黑棕和金色毛发，另一种是褐黑素，负责形成红棕色雀斑与红色毛发。