Macalady Bio

Jennifer Macalady joined the Geosciences Department and the Ecology Faculty at Penn State in 2004 and currently serves as Director of Penn State’s Ecology Institute and Penn State’s Astrobiology Research Center (ARC). After receiving her graduate degrees in Soil Science at the University of California at Davis, she was a postdoctoral researcher in the Banfield Lab at the University of California at Berkeley. She teaches courses serving non-scientists, undergraduate majors, and graduate students. 

Tell me about a few of your favorite publications?

Jones, D.S., Schaperdoth, I. and Macalady, J. L. 2016. Biogeography of Acidithiobacillus populations in extremely acidic subaerial cave biofilms. ISME Journal 10(12):2879-2891, doi: 10.1038/ismej.2016.74. 

This work by my former Ph.D. student Dan Jones showed that ecologically meaningful microbial populations are much finer-grained than was generally appreciated (at least in environmental microbiology). Our data showed that populations defined using sensitive measures (MLST) had genetic differences correlated with spatial distances over a scale of 10 to 1000 meters. We could also see evidence for past colonization events that interrupt/complicate that genographic pattern at larger spatial distances. 

Macalady, J. L., Hamilton, T. L., Grettenberger, C. L., Jones, D. S., Tsao, L. E.* and Burgos, W. D. 2013. Energy, ecology, and the distribution of microbial life. Philosophical Transactions Royal Society B 368: 20120383.

This is a review paper that harnesses ecological theory emerging from the study of plants (resource-ratio theory) to explain patterns we observe in the distribution of microbes. I love it because it demonstrates something fundamental about why microbes are diverse, and because it provides a conceptual model that we can use to predict which microbes are where when, and why.

Dattagupta, S., Schaperdoth, I., Montanari, A., Mariani, S., Kita, N., Valley, J. W. and Macalady, J. L. 2009. A novel symbiosis between chemoautotrophic bacteria and a cave-dwelling amphipod. ISME Journal 3: 935-943.

This work spearheaded by my former postdoc Sharmistha Dattagupta shows how quickly and easily microbe-animal symbioses can develop. It was beautifully executed from conception to publication — that made it one of the most fun projects I can remember.  The symbiosis described here is isolated/endemic (because it is in the terrestrial subsurface) and is probably less than 100,000 years old. 

How did you become a caver?

I started caving in 2004 in Italy. An Italian geologist (Alessandro Montanari) told me about a cave he discovered with his caving group as a teenager. At that point, I was just starting a career in academia studying extremophile microbes. Montanari sent me into the sulfidic section of the Frasassi cave system, and I emerged completely stunned 8 hours later. As soon as I saw Frasassi, I knew there was a lifetime of important questions to explore in caves.

Anything else?

As an undergraduate student, I studied Geology and Russian language at Carleton College (1991). Although I grew up elsewhere, my parents, grandparents, and great-grandparents lived near the anthracite coal mining town of Shamokin, PA. I speak Italian and have a dog named Lavastoviglie (Dishwasher) but we call her Lava for short. I *heart* xkcd.