- Co-diversification of Plants and Insects -
Perhaps
the
most
striking
evolutionary
pattern is the extraordinary diversity
of life, and the remarkable predominance of a few
groups of organisms. With over 250,000
described
species, the angiosperms, although geologically young,
comprise
approximately 20% of all living organisms. The insects are
even more
diverse, with at least a million
described
species. A frequently advanced hypothesis to explain the
extraordinary
diversity of these two groups is that
interactions between plants and insects, such as
herbivory and
pollination, have promoted adaptive radiations in
each
group. Our lab uses phylogenetic, ecological, and
population
genetic tools to test this hypothesis on a variety of
scales in
diverse plant and insect groups.
- Pollination Biology of
Joshua
Trees -
A
major research focus in our lab is on the pollination biology
of
yuccas, and in particular that of the Joshua tree (Yucca
brevifolia). Like
all
yuccas, Joshua trees are pollinated exclusively by yucca
moths, that in
turn reproduce by laying their eggs in the yucca
flower.
Across their range, Joshua trees are associated with two
distinct,
sister species of moth, and populations of trees associated
with each
moth are both morphologically and genetically
distinct. Our
lab is examining the role of coevolution between the
Joshua
tree and its pollinators in producing the differences between
the two tree types, and in mediating
reproductive isolation between them. We use a variety of
tools
and approaches to address these questions, from observational
studies
and ecological experiments, to phylogenetics
and
population genomics. We are currently developing transcriptome
data
and SNP libraries for the trees and their pollinators. These
tools will
eventually allow us to quantify genomic signatures of
selection acting
on genes associated with co-adaptation between plants
and
pollinators.
- Conservation Genetics -
Population
genetic
tools
offer
many
opportunities to answer important
questions in conservation biology. Our lab is currently
engaged in a
number of conservation genetics projects, including
determining the
species status of the Asian Great Bustard, reconstructing the
introduction and spread of the invasive eastern grey squirrel
in the
Pacific Northwest, and the effects of climate change on
population
growth in Joshua trees.