Angry Birds of Evolution?

My wife likes to feed the birds, hanging various feeders up on the patio as well as throwing peanuts to blue jays, red-bellied woodpeckers, and others. Sometimes they get on the prod, scrapping with their own kind. The hands at the Darwin Ranch commenced to studying testosterone and sensitivity.

Junco image cropped from Unsplash / John Duncan

This research was done on New World juncos, distant relatives of sparrows. These chirpers would get aggressive at times, which included singing songs that meant, "This patch of land ain't big enough for the two of us, old son". They also arbitrarily (read: statement of faith, not science) that testosterone is important to evolution. Not hardly!

While hormones do influence behavior, there is not much going for the idea that testosterone is married up with aggression. Gene expression and sensitivity were built into living things by the Master Engineer. Allegedly angry birds are not the products of evolution, and there is no indication of added genetic information. To extrapolate this testosterone for atoms-to-ornithologist evolution, along with the statement that testosterone is important for that to happen, is fake science.

“Individual variation is the raw material of evolution,” says Indiana University’s Kimberly Rosvall. “We report that free-living birds vary in aggression and the more aggressive individuals express higher levels of genes related to testosterone processing in the brain.” Rosvall’s study of wild junco birds demonstrates that individual variation in brain sensitivity to hormones, not the actual amount of hormone present, correlates with behavior. The study also uncovers a mechanism by which hormones like testosterone promote aggression. The researchers believe their results help explain the evolution of aggressive behavior.

To read the rest, fly over to "Angry Birds".