- 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.