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Learn more about our recent work

short summaries of recently published papers

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A selection gradient on eye size

We measured the reproductive selection gradient on eye size in a population of Daphnia obtusa. We found directional selection favoring larger eyes that was stronger than the selection on body size.

Sir2 is essential for Daphnia longevity

We show that knocking down the gene Sir2 in Daphnia has comparable effects to those in other organisms. This is the first demonstration of a gene affecting life history in Daphnia.

RNAi in Daphnia?

Using a clone that produces a melanic carapace in response to UV light, we developed an easy protocol for knocking down any gene in adult Daphnia. No microinjections required!

Telomerase activity and telomere length

We show that evolved differences in Daphnia longevity cannot be explained by the telomere hypothesis of aging. Short-lived Daphnia have longer telomeres, and maintain them better as they age, than long-lived Daphnia.

Phenotypic plasticity of eye size

Macroevolutionary patterns suggest that eye size evolves in response to light availability. Does phenotypic plasticity of eye size follow the same pattern? No. But it is plastic with respect to resources, and resource limitation may reduce visual capability by >30%.

The unmagical elixir resveratrol

Resveratrol has been advanced as a potentially universal way to extend lifespan without costs. However, we found limited evidence for lifespan extension and substantial suppression of reproduction in Daphnia.

Consequences of breeding system variation for aging

Recombination through sexual reproduction is thought to be an important mechanism for purging the load of deleterious mutations in populations. Thus rare sex may lead to accelerated aging, if that means mutations with age-specific effects accumulate. Our results suggest this hypothesis is wrong.

Ecological divergence of resource-dependent transcriptomes

We sought to identify genes that may be involved in adaptive divergence into different resource environments. Using a novel experimental design, we were able to identify genes associated with ecotypic differences in the response to resources.

Genetic correlations and the frequency of sex

We examined genetic correlations of life history traits in populations that differ in sex frequency to test alternate mechanisms that could cause the correlations. Our results are best explained by correlated selection that is enhanced by frequent sex.