Finger development differs greatly between human and frog (Talk.Origins)
Amphibians and mammals both have five-fingered hands, supposedly homologous structures indicating common descent. However, they develop in completely different ways. In humans, the limb tip (called the apical ectodermal ridge, AER) thickens, and then programmed cell death divides the AER into five regions that develop into digits. In frogs, the digits grow outward from the beginning.
- Sarfati, Jonathan, 2002. Ostrich eggs break dino-to-bird theory. Creation 25(1): 34-35.
(Talk.Origins quotes in blue)
1. Frogs and mammals (and other tetrapods) use the same mechanisms of limb development, including the same HOX genes and the same molecules. All (except a few highly derived frog species) have an AER. The difference between humans and frog is that frogs have webbed feet. Human-like programmed cell death would destroy the webbing.
Nothing Talk Origins says above in any way refutes Sarfati’s description of the two processes, all they do is show:
- That there are some similarities between Amphibian and mammal hand development
- What the reason for the difference is, that being the difference between webbed and unwebbed.
Neither of these is inconsistent with Sarfati’s description of the two processes, so what’s Talk Origins point?