Wickham's musings from Chalke

The male Y-chromosome is certain to be extinct soon; soon in geological time – 125,000 to 150,000 years.

The Y-chromosome which only males have is unstable and decaying. Whereas X-chromosomes in women have the capacity to repair themselves over time by pairing up and swapping genes to minimise bad mutations, Y-chromosomes have no partner and cannot do so. Mutations are gradually creating more and more defects.

1% to 2% of all male infertility is already caused by mutations on their Y-chromosomes and it will increase year by year.

There has been much speculation that our human race will be composed totally of females. If they just re-create themselves, their offspring will be identical to them and our race will never develop.

However, it is also possible that two women could transfer genes to create all-female children but consisting of a blend of their parent’s genes as children are at present. These children, all female, would be perfectly normal and able to mate with the dwindling number of males that were left or in turn transfer genes with another female. However, the process of transferring genes would always have to be artificial (similar to the current process of injecting sperm into an egg but instead injecting nuclear chromosomes from another female) and not by a normal sexual process.

There is a third alternative, though. Some animals have already learnt to by-pass the Y-chromosome. A small rodent has managed to transfer the sex-determining region of the Y-chromosome to another chromosome. The decaying Y-chromosome has been by-passed and disappeared and all its sexual information is safely stowed on genes that can be paired up and shared to minimise future mutations.

The offspring are either male or female as we would recognise them ie their sexual parts and functions, but the males have two X-chromosomes like the females and fertile XX sperm genes (unlike rare XX human males today that are infertile). The rodent can have sons or daughters in roughly equal numbers, their sexual makeup decided only by whether they received sperm from the father carrying the repackaged X-chromosome from him or the original from the mother.

So hurry up blokes, get yourselves sorted out before it’s too late!