The wierd thing for me from phylogony is that deuterostomes (basically a sub-group of bilaterians for the non-biologists) start with the anus first in embriological development.The most recent common ancestor of bilaterian animals (which could be described in a very simplified way* as "anything with a head and tail end"), which most of the Cambrian explosion was about, is a tough nut. The outgroup (sponges, jellyfish, comb jellies and... Blobs) are a diverse bunch each with their own derived quirks, and there is no living bilaterian that is an obviously good proxy for the last common bilaterian ancestor (or the Urbilaterian for short).
This is in contrast to the protosomes which develop mouth first internally.
Which is why 'godidit' is such a comeplling answer for you.The point is what? Can you give me a break here, I have a short attention span. I can not deal with long posts. I will see if I can figure out what your saying though.
Which just about sums up your knowledge of biology really.I thought the first animal was a slug.
A very telling comment, how much of Gould's work have you actually read?A lot of Goulds work deals with the explosion at this time and speculation on how the phyla formed.
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