GAINESVILLE, Fla. --- The observation that males evolve more quickly than females has been around since 19th century biologist Charles Darwin noted the majesty of a peacocks tail feather in comparison with the plainness of the peahens.
No matter the species, males apparently ramp up flashier features and more melodious warbles in an eternal competition to win the best mates, a concept known as sexual selection.
Why males are in evolutionary overdrive even though they have essentially the same genes as females has been a mystery, but an explanation by University of Florida Genetics Institute researchers to appear online in the Proceedings of the National Academy of Sciences this week may shed light on the subject.
Its because males are simpler, said Marta Wayne, an associate professor of zoology in the College of Liberal Arts and Sciences and director of UFs Graduate Program in Genetics and Genomics. The mode of inheritance in males involves simpler genetic architecture that does not include as many interactions between genes as could be involved in female inheritance.
The finding may also be useful to scientists studying why diseases may 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 using microarray analysis, which is a way to monitor the activity of thousands of genes simultaneously. The flies were identical genetically, except that females have two X chromosomes and males have a single X and a single Y chromosome.
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
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University of Florida