cell lineages and bivalves

Robert Guralnick Robert.Guralnick at COLORADO.EDU
Mon Aug 12 17:26:09 CDT 2002

         Dear List Members ---

         Ken Kinman posted a message today concerning the position of
bivalves in the molluscan family tree.  We appreciate that Mr. Kinman has
read our paper where we examine what phylogenetic content - if any - is
contained within the timing of cell lineage changes.  However, we would
like to make sure that the readers of this list understand our intention
with that paper.

         We would like to make clear that we are not willing to make any
claim about Spiralian phylogeny right now based on cell lineage data.  Nor
do we believe our paper should be used to argue about the position of major
Spiralian clades.  The dataset shows some patterns that appear consistent
with other traditional datasets (gastropods, position of echiurans) and
some that are not (bivalves, sipunculids, polychaetes).  Do we know the
true tree?  No.  Are cell lineages going to provide the final
answer?  No.  They, along with multiple other kinds of data, may eventually
resolve uncertain areas.

         We therefore would like to make absolutely clear that we do not
agree with Kinmans' statements about the bivalves.  And we hope that other
readers who might examine our paper understand that our exploratory
analysis is not meant to make any definitive claim about phylogenetic
position of any particular group.  We ran the data we collected in a manner
which we believe is reasonable and reported the results as such.   We were
surprised and pleased to recover a tree for gastropods consistent with
other datasets and we believe there is phylogenetic content to be retrieved
from cell lineages.  But we are as certain that there are improbable
groupings in this analysis as well.

Best regards,
Rob Guralnick

Dr. Robert Guralnick
Assistant Professor and Curator of Invertebrates
EPO Biology and CU Museum
University of Colorado
Boulder, CO 80309
ph: 303-735-0178

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