Tips jar

In lieu of a laboratory meeting, we typically chat over coffee at the Smart Museum of Art every morning. Recently, they introduced a “vote with your tips” mechanism in which you can choose between two alternative tip jars. On Jacopo’s birthday, these were the options:

IMG_20160722_092846

Looking for a postdoc

With Gyuri leaving for Sweden, the laboratory is short of a postdoc. I am therefore looking for a new postdoc who could start in late 2016 or early 2017. Here below I past the ad I am circulating.

Postdoctoral position — Allesina Laboratory, University of Chicago

The Allesina laboratory at the University of Chicago is looking for a postdoc, starting in late 2016 or early 2017. The interests of the laboratory include ecological networks (food webs, mutualistic, competitive networks), community ecology, and theoretical ecology in general. The focus of the lab is on the development of new mathematical, statistical and computational methods for the analysis of ecological systems. More information on the research interests can be found here. A list of recent publications from the laboratory is here.

The candidate should have a strong mathematical background, be well-versed in statistics, and fluent in at least one of the programming languages used in the laboratory (C, python, R). Knowledge of Linux, Git, LaTeX, and SQL is a plus. Candidates with a background in mathematics or physics are also encouraged to apply.

To apply, please send an email including a CV, a brief description of research interests and experience, and the name of two letter writers to Stefano Allesina (sallesina@uchicago.edu).

Note: Gyuri Barabas and Matthew Smith will be at ESA Annual Meeting. If you are attending and are interested in this position, make sure to contact them to hear about life in the laboratory.

Two new papers

Two papers I am very fond of just came out.

The first one deals with competition: for decades, we’ve been teaching undergraduate students about the principle of competitive exclusion, showing the simple and appealing notion that intra-specific competition has to exceed inter-specific competition for two species to coexist. Often, however, we fail to mention that this simple rule does not extend to more than two species (guilty as charged).

Can we say anything interesting about the role of intra- and inter-competition in determining the stability of large systems? Turns out that some fairly old results in linear algebra, mixed with more recent advances in random matrix theory,  can be used to write simple conditions for the stability of large competitive communities.

György Barabás, Matthew J. Michalska-Smith & Stefano Allesina
The effect of intra- and interspecific competition on coexistence in multispecies communities
The American Naturalist, 2016

Interestingly, when we have more than two species we can think of how interaction strengths should be arranged to maximize (minimize) stability. Thanks to some very intensive numerical searches, we were able to show that these cases correspond to visually beautiful and ecologically reasonable patterns of interaction strengths:

The second paper takes a new angle to study a very old problem: are modular structures more conducive to stability than random ones? This idea was already put forward by Robert May at the end of his celebrated 1972 paper—yet, a good method to settle this question once and for all was lacking.

We have found a new way to calculate the stability of large random matrices with block structure, showing that rarely modularity has a positive effect on stability:

Jacopo Grilli, Tim Rogers & Stefano Allesina
Modularity and stability in ecological communities
Nature Communications, 2016

One interesting anecdote about this paper: Jacopo and I had been working on it for a while, and had received positive reviews from Nature Communications. However, we didn’t have a way to show that our conjectures were right. At the end of Dec 2015, I was at the Santa Fe Institute for a workshop. I gave a talk on this topic, and Charles Bordenave told me that a friend of his, Tim Rogers, had developed a method that could be used to perform this type of calculation. On Christmas day—thinking that at Christmas everybody’s good—I emailed Tim, asking whether he’d be able to help us out. Come New Year’s Eve and I receive an email from Tim: he had done the calculation, confirming our conjectures exactly!

The method Tim developed is based on quaternionic functions—I believe this is the first paper in ecology to ever mention quaternions in the abstract…

The Little Black Book

In Italy in the 1970s, youth belonging to counterculture movements would march in the streets, parading a copy of the Little Red Book  containing quotations from the writings of Chairman Mao Tse-tung.

Yesterday I turned 40, and to celebrate this very round anniversary, Gyuri, Jacopo, Liz and Matt presented me with a Little Black Book containing many of the things I often repeat, or particularly memorable utterances.

blackbook

This was a truly moving gift, which made me laugh out loud — my labmates know me too well! (It also made me think that I am slowly becoming a grumpy old professor, always repeating the same Mantras)

I will keep the notebook in the lab, so that whenever someone feels the urge to record memorable quotations, they can be saved for posterity.

Joining NICO and PLoS Computational Biology

With the new year, I’ve been invited to join the Northwestern Institute on Complex Systems as an External Faculty, and the Editorial Board of PLoS Computational Biology.

nico-logoNICO is an institute dedicated to the study of complex systems, and is part of Northwestern University, in Evanston (a short train ride from Chicago). It is directed by Luis Amaral and Brian Uzzi, two of the best researchers working at the interface of networks and complex systems. I am very much looking forward to work with the faculty there, and I am very interested in the courses and conferences organized by the Center.

ploscb-logoPLoS Computational Biology is one of my favorite journals. I’ve published seven papers in the journal so far (three last year: 1, 2, 3), and I often reviewed and guest-edited for the journal. I am very happy to join the board as an Associate Editor, and I hope this will help increase the number of submissions from ecologists, as well as foster a dialogue between quantitative ecologists and other biologists interested in the computational, statistical, and mathematical aspects of the discipline.