Previously, scientists had predicted that male Y chromosome would be extinct within as little as 100,000 years. One geneticist, Bryan Sykes, wrote a book called Adam's Curse speculating that the world would soon be stripped of male humans. From the BBC:
Previous research has suggested the Y sex chromosome, which only men carry, is decaying genetically so fast that it will be extinct in five million years' time.
A gene within the chromosome is the switch which leads to testes development and the secretion of male hormones.
Turns out that we are all worrying over nothing, because reports of the chromosome's extinction may have been exaggerated. In a study published in Nature, researchers compared human Y chromosomes to those of chimps, which are about 6 million years behind us in evolutionary terms, and rhesus macaques, which are 25 million years behind. They found that the chimp chromosome has no genes the human one doesn't have, and the rhesus chromosome has just one that we lack. So basically, the Y chromosome has dropped just one gene in 25 million years.