A VIDEO study of hairy, black, seaweed-loving flies has revealed one reason why size is
important when it comes to selecting a mate.
Across the animal kingdom, females tend to prefer large males - it is the single most preferred
characteristic - and scientists have offered many explanations.
In today's issue of Nature, Dr Thomas Day and colleagues at the Queens Medical Centre,
Nottingham, report that they have discovered why large mates benefit female seaweed flies,
insects found around rocky coastlines in Britain.
Dr Day discovered that a big male was more likely to have genes that gave his larvae a better
chance of survival. This meant that, as the species evolved, offspring of females with a genetic
prediliction for big mates thrived and also inherited a predisposition to seek large males
themselves. This genetic trait is now universal in the females of the species.
Dr Day said that this was likely to be a general finding in many species but he was unwilling to speculate on the implications for humans.
"There are many other features, such as shape, intelligence, interests and personality at work in humans," he said. "I don't think one can say that it is good for men to be big."
