Two recent accounts of rapid speciation in Conus may be of interest to you :

1. Proc. Natl. Acad. Sci. (USA) 96, (12), 6820-6823 (1999)
For a fascinating account of the rapid evolution of cone shell toxin genes
(with a commentary by Jon-Paul Bingham) see the featured News in Science
[http://www.abc.net.au/science/news/ScienceNewsRecentIdx.htm] segment from
the ABC "The Lab" Science News Stories for 9 June 1999, entitled " Deadly
sea snails have fast changing genes"
[http://www.abc.net.au/science/news/stories/s28512.htm], (see also Reuters
[http://customnews.cnn.com/cnews/pna.show_story?p_art_id=3822071&p_section_n
ame=alt&p_art_type=112542&p_subcat=other+animals&p_category=animals] ; and
ABCNEWS
"Snails not slow at evolution"
[http://www.abcnews.go.com/sections/science/DyeHard/dye990616.html]).
The original article by Thomas F. Duda Jr.* and Stephen R. Palumbi from the
Department of Organismic and Evolutionary Biology, Biological Laboratories,
Harvard University appeared in Proc. Natl. Acad. Sci. (USA) 96, (12),
6820-6823 [http://www.pnas.org/cgi/content/abstract/96/12/6820] and is
entitled "Molecular genetics of ecological diversification: Duplication and
rapid evolution of toxin genes of the venomous gastropod Conus".
Abstract: "Predatory snails in the marine gastropod genus Conus stun prey by
injecting a complex mixture of peptide neurotoxins. These conotoxins are
associated with trophic diversification and block a diverse array of ion
channels and neuronal receptors in prey species, but the evolutionary
genesis of this functional diversity is unknown. Here we show that
conotoxins with little amino acid similarity are in fact products of
recently diverged loci that are rapidly evolving by strong positive
selection in the vermivorous cone, Conus abbreviatus, and that the rate of
conotoxin evolution is higher than that of most other known proteins. Gene
duplication and diversifying selection result in the formation of
functionally variable conotoxins that are linked to ecological
diversification and evolutionary success of this genus"]. Also contains data
about Conus lividus.BGL.

2. Proc. Natl. Acad. Sci.(USA): Vol. 96, Issue 18, 10272-10277, August 31,
1999
The latest Duda & Palumbi paper from the Department of Organismic and
Evolutionary Biology, Harvard,
contains an evolutionary tree of 70 Conus species based on intron sequence
data. Available on-line in the 31 August issue of Proceedings of the
National Academy of Science: Vol. 96, Issue 18, 10272-10277, August 31,
1999. [http://www.pnas.org/cgi/content/abstract/96/18/10272] and entitled :

"Developmental shifts and species selection in gastropods" by Thomas F. Duda
Jr. and Stephen R. Palumbi.
Abstract: "The fossil record of marine gastropods has been used as evidence
to support the operation of species selection; namely, that species with
limited dispersal differentially increase in numbers because they are more
likely to speciate than widely dispersing species. This conclusion is based
on a tacit phylogenetic assumption that increases in species with limited
dispersal are solely the result of speciation within monophyletic groups
with low dispersal. To test this assumption, we reconstructed a phylogeny
from nuclear sequence data for 70 species of the marine gastropod genus
Conus and used it to map the evolution of developmental mode. All eight
species without planktonic life history phases recently and independently
evolved this characteristic from ancestors with planktonic larval phases,
showing that transitions in developmental mode are common in this group. A
simple model of species diversification shows that such shifts can control
the relative numbers of species with and without dispersing larval stages,
leading to apparent species selection. Such results challenge the conclusion
that increases in the number of nonplanktonic species relative to species
with planktonic larvae over geologic time is necessarily a result of higher
rates of speciation of nonplanktonic lineages and show that demonstration of
species selection requires a phylogenetic framework."
=========================================
- If anyone knows of other or similar studies on rapid speciation in Conus I
would be most interested to learn of such studies.
Bruce Livett
=========================================
Bruce, Dianne, Andrew and Erica LIVETT
48 Nicholas Street
Ashburton
VICTORIA 3147
AUSTRALIA
==========================================
Telephone at home : +61-3-9885-2947
Work: +61-3-9344-5911 Fax: +61-3-9347-7730
Email: [log in to unmask]
URL: (Cone Shells) http://grimwade.biochem.unimelb.edu.au/cone/
****************************************************************************
******************