Not sure what you mean by "completely genetic". What cause other than
genetic would "handedness" be due to?
Paul M.
> ----------
> From: Charles L Powell
> Reply To: Conchologists List
> Sent: Thursday, January 6, 2005 10:07 AM
> To: [log in to unmask]
> Subject: Foram "handedness" was Re: fake shells... the Cebu Shell
> Daktari strikes!
>
> Not directly mollusk related, but planktonic foraminiferal "handedness"
> may
> be completely genetic as the different "forms" are now being assigned to
> different species. See Kucera, M., and Kennett, J.P., 2000, Biochronology
> and evolutionary implications of late Neogene California margin planktonic
> foraminiferal events: Marine Micropaleontology, v. 40, p. 67-81.
>
> Best,
>
> Chuck
>
> Charles L Powell, II
> Western Earth Surface Processes Team, MS 975
> U. S. Geological Survey
> 345 Middlefield Rd.
> Menlo Park, CA 94025
> [log in to unmask]
> (650) 329-4985
>
>
>
> Andrew Grebneff
> <[log in to unmask] To:
> [log in to unmask]
> TAGO.AC.NZ> cc:
> Sent by: Conchologists List Subject: Re:
> fake shells... the Cebu Shell Daktari strikes!
> <[log in to unmask]>
>
>
> 01/05/05 03:58 AM
> Please respond to
> Conchologists List
>
>
>
>
>
>
>
> > However, mollusks are relatively unusual in having many kinds that
> >are normally distinctly asymmetric. Many forminifera have
> >snail-like coiled shells; these can be sinstral or dextral, too.
>
> Foram handedness is temperature-controlled, with no genetic
> component, and is unrelated to gastropod coiling. Indeed, the
> organisms (currently in kingdom Protists, so they are not animals or
> "creatures") themselves are basically "amorphous" blobs of protoplasm
> & organelles. I wonder how they manage to secrete such regular and
> beautiful shells?
>
> ----------------------------------------------------------------------
> [log in to unmask] - a forum for informal discussions on molluscs
> To leave this list, click on the following web link:
> http://listserv.uga.edu/cgi-bin/wa?SUBED1=conch-l&A=1
> Type your email address and name in the appropriate box and
> click leave the list.
> ----------------------------------------------------------------------
>
>
----------------------------------------------------------------------
[log in to unmask] - a forum for informal discussions on molluscs
To leave this list, click on the following web link:
http://listserv.uga.edu/cgi-bin/wa?SUBED1=conch-l&A=1
Type your email address and name in the appropriate box and
click leave the list.
----------------------------------------------------------------------
|