Hornier Male Means a Better Male

Ancient ferocious Celtic warriors knew why they put horns on their helmets (it was the Celts, not the Vikings, that adorned their helmets!). Because a bigger horn means you are a better male.

This is real, at least in the case of the alpine ibex.
A new research found a perfect correlation between horn size of mature alpine ibex males and genetic diversity. Greater genetic diversity is linked to a greater chance of survival.

"The size of the horns reliably advertises the genetic quality of the ibex-and the bigger, the better," said co-author Dr. David Coltman, an evolutionary geneticist at the University of Alberta.

Horn sizes among younger ibex (1-6 years-old) were relatively similar, no matter their genetic composition. But when males reached a certain age (7 to 12) and they started to compete for reproductive rights, horn length was linked to genetic diversity: the greater the diversity, the greater the length of the horn, not mentioning that bigger horns were more powerful weapons in the male fights.

This supports the mutation accumulation theory of aging: natural selection decreases with age, so that mutations induce effects that accumulate over time and differences in genetic quality turn obvious as an organism ages.

The genetic analysis was made on over 150 ibex and took into consideration environmental factors that affect ibex horn size.

"We've learned from other species, such as deer and sheep, that horn or antler size can be a good indicator of an individual's quality and reproductive success. We wanted to see if the same could be said for alpine ibex, and we found that it can." said Coltman.

"[The horns] require a lot of energy to build and then carry around. They can be a meter long and are quite heavy, and the ibex carries them for their lifetime, unlike antlers which are shed every year. They also cause the ibex to lose heat in winter, because their core is heavily vascularized."