Re: webbing

21 Jul 1995 20:00:05 GMT

Alex Duncan ( wrote:
: In article <3ubsmn$> HARRY R. ERWIN,
: writes:

: >The fruitfly geneticists have been getting into this area for a
: >couple of decades, and their genes are starting to match up to those found
: >in vertebrates (homeobox genes in particular). For example, the vertebrate
: >brain seems to be segmented, with the segments matching those found in the
: >front end of arthropods.

: I think I recall reading somewhere that the gene that controls
: segmentation of the arthropod abdomen is homologous to the gene that
: controls segmentation of the vertebrate neck. Anyone else hear this?

Pretty close. Actually the hind-brain. This has clarified the perception
that Amphioxus was brain-less. Not so--the vertebrate brain corresponds to
the front end of its nerve chord. This all seems to indicate that Romer's
speculations on the vertebrate body as a chimera of a tunicate barrel and
a neotenous larval element used for dispersal were fairly accurate.

Harry Erwin
Home Page: (try a couple of times)
PhD student in comp neurosci: "Glitches happen" & "Meaning is emotional"