MALE wood mice have come up with an ingenious strategy to maximise their chances of fatherhood – altruistic sperm. Thousands of their sperm line up head to tail, making a long express train that can wiggle its way to an egg much faster than a lone swimmer.
“When I saw it I couldn’t believe my eyes. And I’ve been working on sperm for 30 years,” says Harry Moore, a biologist from the University of Sheffield. He thinks the sperm have evolved the trick in a bid to outcompete sperm from other wannabe dads.
Common wood mice (Apodemus sylvaticus) are highly promiscuous.…
