brief introduction：nike kids shoes sizeDespite a well-documented history of dramatic genetic2 decay, the human Y chromosome3 has over the course of millions of years of evolution managed to preserve a small set of genes
brief introduction：Despite a well-documented history of dramatic genetic2 decay, the human Y chromosome3 has over the course of millions of years of evolution managed to preserve a small set of genes4 that has ensured not only its own survival but also the survival of men.
