Teeth developing in bird embryos—does it prove evolution? 11
June 2003 ‘Birds with teeth turn the clock back 70 million years
… And they could help to cure baldness’ So trumpeted TimesOnline
(UK), 4 June 2003. But, as commonly happens, the title of the
actual paper that inspired this statement was much less
exciting: ‘Development of teeth in chick embryos after mouse
neural crest transplantations.’1 What did the researchers
actually achieve? They transplanted the part of a mouse embryo
that normally produces teeth into the part of a chick’s embryo
that produces the head of the bird. They found that the mouse
parts continued their development, forming the beginnings of
teeth, some surviving up to 18 days. Using staining techniques
with microscopy, the authors demonstrated the activities of
various genes considered to be involved in tooth formation, both
in the mouse tissue and the surrounding chick tissue. Mouse
genes known to be involved in tooth formation were active in the
tooth germs (beginning teeth) and