Re: Chemical messengers for digital identity

[Gigi and Ralph <gbabcock@best.com>]

I apologize for the cross posting.

There is a report summarizing some of the content of the Dahn and Fallon paper, 
"Interdigital Regulation of Digit Identity and Homeotic Transformation by 
Modulated BMP Signaling" (_Science_, Volume 289:438-441, July 21,
2000), at <www.eurekalert.org/releases/uwm-ept071800.html>.  Experiments on the 
feet of chicken embryos indicate that digital identity is not fixed long before 
the formation of the digits, as had been supposed, and is
subject to change during embryo development.

This research could have implications for the perceived problems encountered 
when comparing the anatomy of non-avian maniraptoran manus digits with the 
incipient wing digits in living bird embryos (i.e. is the bird alula
indeed digit #1 or digit #2?).

-- Ralph W. Miller III       gbabcock@best.com