The male-specific Y-chromosome is shrinking – and it’s happening at different rates across species.
Researchers discovered that a marsupial’s Y-chromosome is genetically denser than the human Y-chromosome, meaning animals such as the tammar wallaby are bounds ahead on the “manliness” scale.
Despite the shrinking Y-chromosome, there is no risk of men becoming extinct, according to lead researcher Dr Paul Waters:
“Y-chromosomes have been completely lost in other species, such as in some rodents, and genes important for male development have moved somewhere else in the genome. The master switch that turns on male development can change and move around the genome, but the result will remain the same.
“Men will always be men, irrespective of the size of the Y-chromosome.”