The Carnival of Evolution collects the best blog posts on evolution from the last month. It's always a good read. It's hosted by a different blogger each month. This month it's on the blog 'The Atavism'.
If you're wondering what an atavism is, it's an ancestral trait that appears in an individual of a species that normally does not display that trait. For instance, whales evolved from four legged terrestrial ancestors. Their forelegs have become highly modified to flippers, while their hindlimbs have almost completely disappeared (only present as a remnant of the hindlimb girdle). But, from time to time examples of whales and dolphins with rudimentary hindlimbs are found. Mostly is it only the main bones of the leg (the femur, tibia and fibula) that are present, but examples with a complete set of foot bones have been documented too.
|Atavistic hindlimbs on a dolphin captured by Japanese 'researchers' off the coast of the infamous Taiji, the town featured in the movie 'The Cove'.|