of the digits proceeds from posterior to anterior direction in frogs, but from head to tail in salamanders.
nThe neo-Darwinian explanation of
developmental genetics presupposes that homologous structures in two different organisms are produced by
similar genes, and
that homologous structures are not produced by different genes – this is now known NOT to be the case.
nIt has also been discovered that
non-homologous structures commonly arise from identical genes.
“… the inheritance of homologous structures from a common ancestor … cannot be ascribed to
identity of genes”,