20th International Congress of Arachnology

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DENVER MUSEUM OF NATURE & SCIENCE REPORTS | No. 3, July 2, 2016
20th International Congress of Arachnology
Student - Oral presentation
Straightening out the pseudoscorpion
backbone
Julia G. Cosgrove1, Mark S Harvey2, Gonzalo Giribet1
1Museum of Comparative Zoology, Harvard University,
26 Oxford St, Cambridge, MA, 02138, USA; 2Western
Australian Museum, Locked Bag 49, Welshpool DC, WA
6986, Australia
Over the last century there have been four main
hypotheses proposed regarding the classification of
groups within the arachnid order Pseudoscorpiones:
Chamberlin, 1931; Beier, 1932; Muchmore, 1982; and
Harvey, 1992. While these classification schemes are
primarily concordant, especially in contrast to the
multitude of ideas proposed in the 19th century, the
placement of a few particular groups continues to
be debated, notably the superfamily Feaelloidea and
families Cheiridiidae, Pseudochiridiidae, and Sterno-
phoridae. Recently, molecular data have begun to shed
new light on our understanding of pseudoscorpion
phylogenetics, however relationships between some key
families and superfamilies remain unresolved. We have
generated de novo transcriptomic data from 23 species
representing 18 of the 26 currently recognized families
in order to infer the pseudoscorpion phylogeny using a
variety of phylogenetic inference methods and models of
evolution. This data will also be used to estimate diver-
gence times within Pseudoscorpiones and to compare
rates of molecular evolution between lineages. We will
discuss our findings as well as the implications of a
well-resolved and dated pseudoscorpion phylogeny that
will provide the necessary backbone from which we can
investigate the evolution of morphological characters
including silk and venom, as well as mating and disper-
sal behaviors.
Keywords: phylogenomics, pseudoscorpiones, systematics,
divergence dating
Oral presentation
Genetic mosaic among ecologically similar
species within an adaptive radiation of
Hawaiian spiders
Darko D. Cotoras1,7, Michael S. Brewer2 , Ke Bi3,4, Stefan
Prost1 , David R. Lindberg1,5, Rosemary G. Gillespie6
1Department of Integrative Biology, University of Cali-
fornia, 3060 Valley Life Sciences Building, Berkeley, CA
94720-3140, USA; 2 Department of Biology, East Carolina
University, 1000 E 5th St., Greenville, NC 27858-4353,
USA; 3 Museum of Vertebrate Zoology, 3101 Valley Life
Sciences Building, University of California, Berkeley, CA
94720-3160, USA; 4 Computational Genomics Resource
Laboratory (CGRL), California Institute for Quantitative
Biosciences (QB3), University of California, Berkeley, CA
94720-3102, USA; 5 Museum of Paleontology, University
of California, 1101 Valley Life Sciences Building,
Berkeley, CA 94720, USA; 6Department of Environmental
Science, University of California, 137 Mulford Hall,
Berkeley, CA 94720-3114, USA; 7Current affiliation:
Department of Ecology & Evolutionary Biology, Univer-
sity of California, Santa Cruz, Santa Cruz, CA 95064
USA; Department of Entomology Center for Comparative
Genomics, California Academy of Sciences, 55 Music
Concourse Drive, San Francisco, CA 94118, USA
The interplay between isolation and time in the ini-
tiation of adaptive radiation is central to understanding
the dynamics of rapid diversification events. The chrono-
sequence of the Hawaiian Islands provides an ideal system
to explore this fundamental process. Here, we focus on
a radiation of long jawed spiders, genus Tetragnatha, to
examine the genetic signatures of early events of speciation.
Specifically we investigated how ecologically similar species
have differentiated genetically in the course of an adap-
tive radiation. Using a transcriptome-based exon capture
approach, we examined relationships between populations
of three closely related species (T. brevignatha, T. waika-
moi and T. macracantha) from the youngest of islands of
the Hawaiian chain, Lana’i, Maui and Big Island. The data
shows that the originally described three species could be
separated in at least five genetic clades. A key finding is that