Genetic switch for limbs and digits found in ancient fish

[Mr. McD]

Genetic instructions for developing limbs and digits were present in primitive fish millions of years before their descendants first crawled on to land, researchers have discovered.

Genetic switches control the timing and location of gene activity. When a particular switch taken from fish DNA is placed into mouse embryos, the segment can activate genes in the developing limb region of embryos, University of Chicago researchers report in Proceedings of the National Academy of Sciences. The successful swap suggests that the recipe for limb development is conserved in species separated by 400 million years of evolution.


http://www.uchospitals.edu/news/2011/20110711-limb.html

[azul]

1. Some one or thing programmed

a whole repertoire of morphologies that could be activated long long ago.

And every drop of water in the ocean has DNA in this most fecund little world.