During a seminar this Wednesday (13th May), a female scientist who studies sex chromosomes in a wide range of animals predicted that the human Y chromosome might disappear in 5.8 million years’ time! The male audience among us could do nothing other than smiling rather wryly at this female specialist, but the female audience need not rejoice too early. The scientist further predicted two fates of the human species: either we will die out because of inability to reproduce, or new human species will evolve. The latter is actually not as far-fetched as it seems, because there’s a type of mouse called mole vole which has split into two lineages because of changes to sex chromosomes. So why are humans heading down this predicament? It is thought that the sex chromosomes for mammalians, to which humans belong, evolved about 160 millions ago. There are two sex chromosomes X and Y, with two X’s giving rise to females and the X, Y combination to males. When reproductive cells are produced by a