"When humans run out of Y chromosome, they might become extinct..." via RT image: Pixabay An analysis of the genetics of spiny rats may have shown men's future, scientists say A study has led researchers to believe that the male Y chromosome might disappear in the future. Such a hypothesis emerged after scientists examined a Japanese spiny rat species. The rats in question no longer depend upon the old male chromosome to encode male sex characteristics. Instead, a "totally new" one has evolved to take its place, scholars from Hokkaido University revealed in work published last month in the journal Proceedings of the National Academy of Sciences. While the Y chromosomes of mammals have been shrinking and deteriorating in function over millions of years, the analysis of the rats found on the Amami Islands indicates that this new chromosome may now switch on male sex characteristics. Japanese researcher Asato Kuroiwa and other scholars extrapolated the results of the experiment to