Magic embryology: rules for growing a new fetus (Introduction)

by dhw, Thursday, January 23, 2020, 10:01 (1767 days ago) @ David Turell

QUOTE: The vast—and largely non-pictorial—literature on this subject does not offer a global mechanism to explain the rise of diverse forms of animal phyla. Though highly speculative, the model offered here may suggest just such a mechanism.The homologous morphological resemblance among the phyla may, in fact, be due as much to the inevitable topological trajectory of the confined expansion of a primordial spherical membrane as it is to common ancestry. Accordingly, the choices available to natural selection may be limited to the possible variations in proportions of the body parts of otherwise relatively conservative and invariant phyletic forms, rather than simply provided by random genetic mutations resulting from errors in transcription.bAnimal form may thus be seen as the product of physical forces—or biases—acting upon cells and populations of cells with very specific and constrained geometric properties, rather than arising solely from the vagaries of chance." (David’s bolds)

DAVID: Note the bolded comments, which imply there are underlying physical principles that guide these processes as well as genetic instructions, and therefore any chance events are not allowed. Certainly sounds designed by a designer.

dhw: Your second bold is a clear indication that the author believes changing environmental conditions influence the behaviour of cell communities (he calls them “populations), though their “constrained properties” can hardly explain innovation. It is perfectly possible that your “underlying physical principles” may be guided by underlying mental activities. I am not sufficiently au fait with the terminology to understand your first bold, but I’d have thought that all the resemblances were EVIDENCE of common descent. Since you have bolded it, perhaps you can summarize the gist for me. As you know, I am as sceptical as you about “chance” being the driving force of evolution.

DAVID: Homologies are similar formations in structure and for common descent he assumes the lookalikes are all set up by the same physical shaping forces all through time.

Thank you, but I understand “homologies” – it’s the “topogical trajectory” etc. that I don’t understand. But we agree about chance and common descent, so let’s leave it at that.