In psychology, the classic chicken-or-egg conundrum boils down (sorry) to the question of whether thoughts precede feelings ...

From scientists' point of view, knowing which came first, the egg or the chicken, is rather logical. Over time, species evolve according to principles of genetic mutations and natural selection.

More than 20 million egg-laying chickens in the U.S. died last quarter because of bird flu, data from the U.S. Department of ...