Bigger is Better when it Comes to Testes Size and Genome Evolution

Is bigger really better? When it comes to the testes and spreading your DNA, it just might be the case.

A recent study that analyzed a published dataset from 55 species of primates showed a link between molecular evolutionary rates across genome and testes weights.

"In general, the speed of genome evolution is higher for species in which males have large testes in comparison to species in which males have small testes," said researcher Alex Wong, via a press release. "This finding helps us to understand why genomes evolve at different rates in different species, and has implications for our understanding of the relationship between female mate choice and the overall fitness of a population."

After the thorough analyization between testes size and substitution rates in primates, Wong and researchers found a positive correlation when accounting for certain confounding factors.

Through various evolutionary methods, the researchers gave proof to a positive correlation between testicle size and substitution rates in primates. Findings also support the theory that competition between male species where the female mates with more than one male can result in higher spermatogenic activity.

"The current finding of covariance between sperm competition intensity and substitution rates adds to a growing body of knowledge concerning the sources of substitution rate variation," said Wong, via the release. "The extent to which this covariance is widespread is not yet clear; application of robust comparative methods to large phylogenetic datasets in other taxa, such as birds and insects, will help to establish its generality."

What do you think?

More information regarding the study can be found via the journal Molecular Biology and Evolution.