Worms And Regeneration
As Wired notes, "a small piece of a planarian worm can regenerate an entire new body. The worm's ability to regenerate is so powerful that a tissue fragment only 1/279 of the worm's length can grow into a new animal." Researchers have been working to identify all the genes involved in this regenerative process - if human medicine can benefit from understanding salamander regeneration, then it will likely benefit from research into lower forms of life as well. "It's too soon to tell whether research into planarian worms might one day let doctors regrow amputated limbs or diseased organs in people. Nevertheless, since many of the genes found in flatworms are also present in humans, scientists believe they may provide insights into how to use adult stem cells to replace diseased or damaged human tissue."
Link: http://www.wired.com/news/medtech/0,1286,67404,00.html?tw=wn_tophead_3