Early embryology; clockwork construction plan (Introduction)

by dhw, Sunday, October 16, 2011, 08:22 (4788 days ago) @ David Turell

DAVID: Any construction has to have a timing plan. Parts have to be set up to put in place in an orderly fashion. In a building you cannot sheetrock before wires and pipes in the wall are in place.
The same is true in the embryo, but in the beginning all one sees is a ball of blast cells. Eventual areas of the potential 'body' must be identified, placed properly and then development started. Here is the initial clockwork process:

http://www.sciencedaily.com/releases/2011/10/111013153943.htm

Another illustration of the astounding complexity of life’s mechanisms, but this one has a tremendous sting in the tail:

“The mechanism [the Hox clock] that we have discovered must be infinitely more stable and precise [than the Circadian and menstrual clocks]. Even the smallest change would end up leading to the emergence of a new species.”

I need guidance on this, but they seem to be homing in on the mechanism which actually drives evolution (as opposed to natural selection, which only ensures that innovations survive). It’s frustrating that they throw this titbit in at the last minute without further explanation, but perhaps David you could enlighten us with your own slant on that last sentence.