Hot Student Papers

A roadmap for urban evolutionary ecology

29 Nov 2018 - 1:31pm
Members of Marc Johnson's lab

Today’s world is one of unprecedented environmental change. Cities, one of the leading causes of such change, are the fastest growing ecosystems on Earth. Over half of all humans now live in urban habitats, making understanding how cities influence the ecology and evolution of species of central importance. In our Perspective article, we provide a roadmap of urban evolutionary ecology. We begin by recounting a brief history of the field of urban ecology and the development of urban evolution. We follow by synthesizing current research in urban evolutionary ecology and identifying six important, yet unresolved questions that need to be addressed.

Methodological review and meta-analysis of dilution assays for estimates of virus- and grazer-mediated phytoplankton mortality

27 Nov 2018 - 7:45am

In a new paper in Limnology and oceanography, methods, recent PhD graduate Michael Staniewski (Short Lab), reviews methodological differences among modified dilution assay studies, discusses their implications, and provides recommendations for the application of future assays. The modified dilution assay is the only current approach that allows for direct estimates of both grazer- and virus-mediated phytoplankton mortality, without the use of excessive assumptions or conversion factors. A meta-analysis is also presented, based on grazer- and virus-mediated mortality and host instantaneous growth rates extracted from these studies.

Congrats to Michael!

A comprehensive evaluation of Daphnia pulex foraging energetics and the influence of spatially heterogeneous food

13 Aug 2018 - 1:04pm
experimental set-up

In a new paper in Inland Waters, recent PhD graduate Audrey Reid (Sprules Lab), examined how energy expended in finding and consuming algae varies with energy gained in spatially dynamic habitats. Audrey measured of the costs and benefits to Daphnia grazing across a range of algal concentrations. Her paper shows that costs did not rise with algal abundance but benefits did thus explaining why Daphnia seek algal patches in nature.

Congrats to Audrey!

Modern spandrels: the roles of genetic drift, gene flow and natural selection in the evolution of parallel clines

30 Jul 2018 - 10:56am
graph showing changes in the frequency of the cyanogenic phenotype (HCN) with changes in the frequency of either dominant allele (i.e. CYP79D15 or Li)

In a new paper in the Proceedings of the Royal Society (Series B), James Santangelo (Johnson & Ness Labs), modelled how selection, genetic drift and demography interact to drive evolution of traits that are controlled by multiple interacting genes. He found that genetic drift was sufficient to cause consistent directional change in trait frequencies, but the addition of natural selection increased the change in trait frequencies. This paper was published in a special feature in the journal on urban evolution, which James also co-edited.

Congrats to James on his first paper as a graduate student!

The effects of plant sexual system and latitude on resistance to herbivores

17 Jul 2018 - 8:55am
The geographical distribution of monoecious, dioecious, and subdioecious populations of Sagittaria latifolia

In a new paper in the The American Journal of Botany, Ruth Rivkin (Johnson Lab) tested how latitude, plant sexual system, and gender influence the strength of plant-herbivore interactions. She found that herbivores were most abundant on female plants and in dioecious (both male and female plants) populations, and that this trend was strongest in the south.

This is the first paper from Ruth’s ongoing PhD - congrats!