A major motivator for the investigators is the historical lack of diversity in genetics research. For example, the first major study on the genetics of skin tone diversity in Africa occurred only recently. Latin Americans are similarly underrepresented in genetics research, particularly in pigmentation research.
“[This is a] rare example of intense, ongoing adaptation in recent human history and is the first known example of adaptive gene flow at a pigmentation locus in humans,” the authors wrote in their report. The lead author, Meng Lin, is a post-doctoral researcher in genetics at the University of Southern California.
The investigators also analyzed the effect of sun exposure on cell mutations. Very low doses of ultraviolet light—below sunburn level—were shone onto the mice with mutated p53 genes. The mutated cells grew much faster. They reached the level of growth seen at six months in non-UV radiated clones in only a few weeks. Despite this rapid growth, the mice did not develop skin cancer nine months after exposure.