A major evolutionary theory says most genetic changes don’t really matter, but new evidence suggests that’s not true. Researchers found that helpful mutations happen surprisingly often. The twist is ...

Classical Mechanics:** Newton’s second law (F = ma) explains the relationship between force, mass, and acceleration. The law of universal gravitation describes the motion of heavenly bodies based on ...

A growing number of medical experts and law enforcement officials are reversing testimony that put parents behind bars. But ...