A Reply to Carl Zimmer on Embryology and Developmental Biology

I recently read Carl Zimmer’s response to my critique of his November, 2006 article in National Geographic. In this post I will discuss Zimmer’s response to me regarding embryology and developmental biology. The embryonic hourglass is the idea that vertebrate embryos (like those of fish, amphibians, reptiles, birds, and mammals) start off developing very differently, […]