'Tis the season to hang Christmas tree ornaments, but did you know animals can have ornaments, too? It's true. Consider those big unwieldy antlers on a reindeer, or the colorful plumage of the peacock. Conventional theories on natural selection would suggest that these traits are harmful – bright feathers and heavy horns make animals vulnerable to predators. Such traits should have disappeared long ago.
But biologists have concluded that ornamentation actually favors something called sexual selection. Flashy feathers and horns helps males stand out from the crowd when it comes to attracting females. In some cases, these ornamental traits survive, even though in practical terms, they're detrimental to the species. There's also something at play called the "handicap principle" -- Trace Dominguez has the details in today's festive DNews report.
Discovery Wildlife: Why do female reindeer grow antlers?
Britannica: Runaway selection hypothesis
Phys: Study explains evolution phenomenon that puzzled Darwin