Effects of rapid evolution on alternative community states
Species interactions can often allow for multiple different discrete states,
or alternative community states, into which a given community can assemble.
Which state is realized depends on initial conditions, and
this role of history makes predicting community outcomes notoriously difficult.
Feedbacks across spatial scales coupled with coevolution within communities
further complicates matters.
I will use the well-described study system of microbes in
Diplacus aurantiacus nectar to study how rapid evolution alters
alternative community states at both single-community and metacommunity scales.
Maintenance of variation for ongoing eco-evo dynamics
source: alexanderwild.com
Feedbacks between evolutionary and ecological processes that occur because
they operate on similar timescales is called eco-evo dynamics.
For eco-evo dynamics to persist, the variation underlying both
processes must be maintained, yet this fundamental component of eco-evo
dynamics has received little attention.
Pea aphids can evolve resistance to parasitoid wasps rapidly enough to affect
the host–parasitoid dynamics.
Through long-term lab experiments and simulations, we show that aphids
dispersing among patches that vary in parasitoid abundance can produce both
the ecological stability and balancing selection necessary for ongoing
eco-evo dynamics.
Effects of population fluctuations on genome evolution in the wild
How do extreme population fluctuations structure genomes in wild populations?
I’m exploring this question with a population of midges in Lake Mývatn,
Iceland, where they have irregular population fluctuations of about 5 orders
of magnitude.
As part of a long-term monitoring project at Mývatn,
Dr. Árni Einarsson has estimated midge densities, and
collected and stored midge samples since 1977.
I am leveraging this time series of whole-genome and ecological data
to assess how genomic structure is affected by these extreme population dynamics.
Trait coevolution among competitors and coexistence
Coevolution among competitors can result in traits that promote
niche partitioning and coexistence or traits that promote
greater conflict and competitive exclusion.
We used an eco-evolutionary model where competitors “invest” in coexistence- and
exclusion-promoting traits to assess when trait coevolution
should promote coexistence or exclusion.
We found that communities should often contain both types of traits, but
exclusion-promoting traits should more strongly influence trait
coevolution community-wide.
We also found that, despite being more influential, species invested relatively
more in exclusion-promoting traits should be most vulnerable to exclusion by a
new invader.
This may make communities containing multiple species with exclusion-promoting
traits evolutionary transitory.