September 4, 2012
Roosters Prefer Mates That Have The Biggest Comb Size
Lee Rannals for redOrbit.com - Your Universe Online
Size matters, and bigger is always better, at least when it comes to what roosters want when looking at possible mates.
New research published in the journal PLoS Genetics suggests that roosters select the girl with the largest hairdo, or "comb."
The scientists, from LinkÃ¶ping Universitet, say that the larger the comb of a hen, the bigger dose of sperm she will receive from the rooster, which leads to more eggs.
Domestic hens have larger combs, as well as denser bones, when compared to wild hens. According to the research, this feature can be changed through human manipulation.
The scientists say that the greater the bone mass a hen has, the more eggs she is able to lay. They have spotted a clear correlation between comb size and bone mass in chickens from a cross between red jungle fowl and domestic chicken.
After spotting this correlation, the team set up a study to determine where these chickens were crossed for several generations, allowing them to "map" the functions of individual genes.
After the eighth generation, the team found an area that had a strong effect on the weight of the comb, as well as bone mass and fertility.
The genetic variation has gradually decreased over the course of domestication, according to the findings.
In domestic chickens, there are about 40 known small regions with stable genes that help to govern their typical "domestic" characteristics. The team also found two genes connected to each other that influence several characteristics simultaneously.
By regulating the production of cartilage, the scientists influenced the combs, and ultimately the egg production.
“The original hens have smaller combs, thinner legs, and lay fewer eggs. When people bred for the characteristic of laying many eggs, the comb grew automatically,” evolutionary geneticist Dominic Wright, who led the research, wrote in the journal.
The scientists said that in nature, the comb is a sexual ornament, and individuals with the most impressive ornaments are favored by the other sex. This enables them to obtain more offspring than their competitors.
In conclusion, it may be safe to say that if Snooki from the Jersey Shore were a hen, she would be able to attract many a rooster suitor.