The Y chromosome may have gotten a bad rap. Despite the claim that this male sex chromosome is mostly junk, new research suggests it's actually a lean, mean, highly evolved machine for producing the fittest males possible.

The findings, presented Friday (Nov. 9) here at the American Society of Human Genetics' annual meeting, dispute the notion that historically most men in a generation have not passed on their genes while a few lucky guys fathered hordes of children.

Read more at CBS News.