Humans do not have tails, but do we have “what it takes” for a tail? Hens don’t have teeth, but they have the genes for it. With atavism, it is as if our genomes serve as archives of our evolutionary ...

All vertebrate embryos follow a common developmental path due to their common ancestry. All have a set of very similar genes (the homeobox genes) that define their basic body plan. As they grow, the ...

PROF. MACBRIDE, in his brilliant review (NATURE, Oct. 25, p. 639) of the recent embryological works by Dürken, Schleip, and Przibram, raises questions which are so fundamental in modern biology that I ...