16 SEP 2011 by ideonexus
Hen's Teeth
Some atavisms can be produced in the laboratory. The most amazing of these is that paragon of rarity, hen’s teeth. In 1980, E. J. Kollar and C. Fisher at the University of Connecticut combined the tissues of two species, grafting the tissue lining the mouth of a chicken embryo on top of tissue from the jaw of a developing mouse. Amazingly, the chicken tissue eventually produced tooth-like structures, some with distinct roots and crowns! Since the underlying mouse tissue alone could not prod...An experiment from 1980 that stimulated hens to grow teeth by triggering a gene holdover from their ancient reptilian ancestors.