PageRank and Food Webs
In 2009, Drs. Stefano Allesina and Mercedes Pascual published a paper that discussed the application of PageRank to food webs, which are networks that depict which animals eat which in an ecosystem.
They are interested in identifying the species that are likely to go extinct and evaluating the impact of those extinctions on the ecosystem. This is a particularly challenging endeavor because all of the different species in an ecosystem interact with each other in a complex way; for example, the extinction of one species may lead to the extinctions of others. Using the PageRank algorithm, Allesina and Pascual ranked species according to their importance in the ecosystems (and therefore how much the ecosystem would be affected if that species were to go extinct).
We discussed PageRank in class, and there is a section devoted to it in the textbook (14.3). Our discussion of the PageRank algorithm was primarily limited to search engines (Google) and the Internet – a page is more important when other pages link to it. I found that Allesina and Pascual’s paper is especially interesting because it shows that PageRank can be applied to real-life food webs.
Link to paper: http://journals.plos.org/ploscompbiol/article?id=10.1371/journal.pcbi.1000494