By IANS
New York : It was Charles Darwin who first noted that males evolve more quickly than females. But why did they do so?
A new study now provides an explanation: It’s because males are genetically simpler.
Researchers at the University of Florida say the reason why males evolve faster though they have the same genes as females is that “the mode of inheritance in males involves simpler genetic architecture (than) in female inheritance”.
Findings of the study, led by Marta Wayne, appear online in the Proceedings of the National Academy of Sciences this week.
The finding could be useful to scientists studying why diseases present themselves — or respond to treatment — differently in men and women.
Researchers examined how gene expression is inherited differently in male and female fruit flies by monitoring the activity of thousands of genes simultaneously. The flies are identical genetically, except that females have two X chromosomes and males have a single X and a single Y.
It turns out that the extra X in females may make answering the call of selection more complicated.
In flies or humans, sex cells from a mother and a father combine to make what eventually becomes an embryo. Females are equipped with two versions of X-linked genes that interact not only with each other, but also with other genes.
Males have only one version of the X chromosome, making for fewer interactions and more straightforward male inheritance, especially since the male’s Y chromosome contains very few genes.
The researchers say this relatively uncomplicated genetic pathway helps males respond to the pressures of sexual selection, enabling them to win females and produce more offspring.
“This research shows how recessive and dominant traits are important in determining variation in populations,” said David Rand of Brown University, who was not involved in the study.