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Jumping Spiders: Reference
and Abstract
Proc. Natl. Acad. Sci. USA, Vol. 99, Issue 7, 4442-4447, April 2, 2002
Sexual selection driving diversification in jumping spiders.
Susan E. Masta* and Wayne P. Maddison
Department of Ecology and Evolutionary Biology, University of Arizona,
Tucson, AZ 85721
Edited by David B. Wake, University of California, Berkeley, CA, and
approved February 8, 2002 (received for review September 18, 2001)
Abstract
Theory predicts that speciation rates should be accelerated in organisms
undergoing sexual selection. In systems involving female choice, sexual
selection acts directly on traits that may be important in prezygotic
reproductive isolation, potentially fostering rapid divergence of such
traits among allopatric populations. Despite the appeal of this concept,
it has proven difficult to document. We provide genetic, behavioral, and
simulation data illustrating that the striking and possibly recent divergence
in traits of male behavior and morphology among populations of the jumping
spider Habronattus pugillis can be attributed to sexual selection.
We have found evidence for varying degrees of lower female response and
offspring viability among some between-population crosses, consistent
with the early stages of speciation. We have developed a gene-tree-based
method for comparing phenotypic and genetic data sets to infer selection,
and have found robust statistical evidence that directional selection
has acted on male traits, by confirming that their rate of fixation exceeds
that of neutral mitochondrial genes. Because these traits are apparent
targets of female choice, the results indicate that sexual selection is
driving divergence of phenotypes potentially crucial to the speciation
process.
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* To whom reprint requests should be addressed at: Department of Biology,
San Francisco State University, 1600 Holloway Avenue, San Francisco, CA
94132. E-mail: smasta@sfsu.edu.
Copyright © 2002 National Academy of Sciences, U.S.A. All rights
reserved.
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