Comments on: Bilaterally symmetrical animals share a common ancestor with a CNS?

By: Bayle

Bayle — Sat, 18 Aug 2007 20:13:16 +0000

Yeah but the question is, did the common ancestor have a CENTRALIZED nervous system?

By: mt

mt — Sat, 18 Aug 2007 06:42:55 +0000

This seems like a no brainer…so to speak. Bilateralizing came about from duplicating, which implies two parallel nervous systems, which equals in toto one non-centralized nervous system. QED

By: Bayle

Bayle — Fri, 20 Jul 2007 22:00:59 +0000

Thanks, that’s neat! I added a link to http://other95.blogspot.com/2007/07/cnidarian-double-whammy-anemone-genome.html in the story above (around ‘have evolved relatively “more”’)

By: Kevin Z

Kevin Z — Fri, 20 Jul 2007 21:38:09 +0000

Thanks for linking to my post! I learned from reading another recent paper on the cnidarian genome (that I posted on here: http://other95.blogspot.com/2007/07/cnidarian-double-whammy-anemone-genome.html) that fly and nematode evolve at a faster rate relative to the genomes of other model organisms and they a greater percentage of intron loss and ancestral gene loss. Perhaps the annelids are more conserved and evolve relatively slowly. I know that both insects and nematodes are very diverse taxa relative to chordates and annelids (and cnidarians for that matter).