You are here

Megan Greischar

Assistant Professor

Megan Greischar

Educational Background

Ph.D., Pennsylvania State University (2014)
B.S., Indiana University (2007)




Parasite life history strategies within the host, especially the timing of replication and transmission, influence disease severity and spread. I study how subtle differences in ecology within and outside the host can generate dramatic differences in parasite strategies. My research program uses two major approaches: (1) building ecologically-detailed models to ask when and why particular strategies would be favored; and (2) developing novel statistical approaches to better characterize parasite traits from existing data.


life history evolution, malaria, disease, transmission, epidemiology, population dynamics


  • Ecology and Evolutionary Biology

Graduate Fields

  • Ecology and Evolutionary Biology


I use models to study why parasites use such diverse strategies to make a living. In particular, I want to understand what processes limit parasite numbers within the host and how parasite population expansion alters the timing and efficiency of onward transmission. My research focuses primarily on malaria infections, including:

1. Why do some malaria infections replicate synchronously in the blood and occasionally cause periodic fevers? If synchrony is beneficial, then why aren't all infections synchronous? Will synchronous and asynchronous parasites respond differently to drug treatment both in the short term and through evolutionary time?

2. Mosquitoes transmit human malaria all too efficiently, but that doesn't mean they are ideal vectors. Mosquitoes are fragile and short-lived, and their numbers can fluctuate substantially over the course of a transmission season. How do malaria parasites alter their strategies within the host to cope with this uncertainty and what could that mean for human health?

3. Malaria parasites can respond plastically to ecology within the host, but what cues exactly do they respond to? I use time series data from malaria infections to understand exactly what cues parasites respond to and whether they are likely to respond adaptively to novel changes in their environment (e.g., drug treatment).

4. Why don't parasites replicate faster? Malaria parasites exhibit huge variation in how fast they proliferate, suggesting that for many species, it might be possible to replicate faster. Is it only a matter of time until slow-growing parasites evolve faster multiplication rates


Please see a current list of publications here.