"These sheep are, in effect, pumping iron without lifting weights."
Quote by Randy Jirtle, a geneticist at Duke University, referencing effects of a DNA change through mutation that gives sheep "beautiful" buttocks.
See the 17 September 2002 issue of Nature to read all about it.
"One changed DNA letter produces 'callipyge' sheep, which amass muscle instead of fat around the pelvis. Some humans might share the trait, Jirtle speculates. 'They'd have relatively large rear ends, and absolutely no fat - like sprinters.'"