My parents are beautiful, I am not yet pretty

Sexy guys can create dull girls, and attractive girls give birth to tasteless boys. That's at least what happens in fruit flies.

(Photo: vanwal) This contradictory genetic pattern is one reason why not everyone is attractive.

The paradox, the researchers explained, is because many traits that enhance male fertility are detrimental to females, and vice versa. For example, female flies spend a lot of time and energy on laying eggs, while males will spend more time to mate.

"Whenever there is a division of roles between the sexes, the traits that make a male successful will not necessarily make success in children ," evolutionary biologist Alison Pischedda at the University of California , USA, said.

She and Adam Chippindale at Queen's University in Kingston, Canada, learned about this genetic conflict. They selected from a large group of fruit flies to choose the three most beautiful and poorest genotypes for each gender. Then they give them cross-breeding and check the health of the born babies.

In any case, the most beautiful mother gave birth to a perfect daughter, but her son was worse, compared to other mothers. And the strong father gave birth to weak girls. The father's genetic pattern does not affect son's health. The end result of this difference is that the best combination of males and females will produce the lowest quality herds.

If the genetic battle between the two sexes is widespread in nature, it will prevent the evolutionary model in which to focus all the best in one branch and eliminate the rest.

This is the first study to show that both parents are perfect for their children. Researchers say more experiments are needed to find out whether this evolutionary paradox is really common in the natural world.

MT