Starfish regeneration

I assume you asking why sometimes when one star fish leg is damaged or cut off then the animal grows back two legs rather than one.

Assuming yes then no one knows for sure but I would think that the answer lies in the mechanisms and genes the star fish has for growing back limbs. When damage occurs to a leg, that triggers a whole load of genes to be activated, that make loads of new proteins whose job it is to grow back a leg. Ocassionally when the damage is severe and right at the part where the star fish leg joins the body, then the signals get a bit confused and the star fish "thinks" it has lost 2 legs rather than one, which is why two legs grow back.

What you may also be interested to know is that the genes in the star fish that do this are very similar to those in mammals (including humans). However in mammals the function of those genes is to tell the developing embryo how and where to grow limbs whilst the foteus is developing. Sadly, they do not do the same thing in adults when the limb is damaged!

Hope that helps

Last edited by David Wynick (19th Mar 2007 10:44:23)