The origin of tetrapods is a complex question that webs together genetic, paleontological, developmental and physical facts.
A very interesting question of evolutionary biology indeed, mobilizing the efforts of many.
Basically, the development of embryos is described by a complex mix of mechanical movements and biochemical inductions of genetic origin.
It is diﬃcult to sort out in this scientiﬁc question what are the fundamental features imposed by conservation laws of physics, and by force equilibria, and what can be ascribed to successive, very speciﬁc, stop-and-go inductions of genetic nature.
Is it a difficult question ? From zygotes you can get individuals with no appendages or with four, six, eight, ten or many (myriapods). It is quite easy to identify what differentiate them: genomes. Genomes which specify the entire spectrum of physico-chemical properties of every part of the developing embryo, as well of the formed individual throughout its existence, in interaction with the environment. And these physico-chemical properties specify every aspect of cellular displacements from zygote to death, including embryogenesis.
That’s the easy part, easy enough for everybody to understand, even if he isn’t a specialist.
It’s much more difficult to understand the mechanisms in detail. And that’s the fun part.
A posteriori, evolution selects the parameters of this process as found in the observed species.
There is a huge misunderstanding of the term “evolution”. Fleury seems to be allergic to the notion of Natural Selection and, as he say, is preoccupied by Evolution not Natural Selection, ignoring the mechanisms known to operate in biological evolution.
The persistence of such an error in the abstract of the paper calls a question: did an evolutionary (or evo-devo) biologist reviewed the paper? I hope the answer is no. I hope that no biologist reviewed the paper.
Filed under: PSection, Uncategorized | Tagged: Anne Dambricourt-Malassé, Discovery Institute, EPJ AP, EPMAG, Jean Staune, John Tempeton Foundation, morphogenesis, neocreationisme, organizer, Organogenesis, origin of tetrapods, positional information, SO, Université Interdisciplinaire de Paris | 1 Comment »