Bacteria flourish in nearly every place on Earth imaginable including in and on humans. They also reproduce and therefore evolve much more quickly than we do, so understanding their evolution is vital to every aspect of our lives. A surprisingly common strategy for bacteria - controlling everything from virulence to production of useful resources such as cellulase - is a form of communication called quorum sensing. Bacterial cells using quorum sensing consistently produce a signal molecule and then detect the concentration of that molecule in the surrounding area. The bacteria generally have a signal-molecule density threshold, called a quorum, that triggers them to start performing a new behavior. The behaviors controlled by quorum sensing are usually only useful if there are enough organisms doing them at the same time. Producing public goods such as light or enzymes […]
After Man: A Zoology of the Future by Dougal Dixon is a fictional non-fiction book proposing possible evolutionary tracks for the species that remain 50 million years after the Age of Man. As a fan of sci-fi and evolution, I couldn’t resist asking Dr. Ofria if I could borrow it when I spotted After Man on his shelf. As with most popular audience books, After Man doesn’t do a perfect job describing evolutionary events, but it is highly entertaining to read through. I also suspect that a very fun unit could be created around After Man for a high school or intro biology course.
One of the nice things about summer is catching up on everything that got put to the side during the semester, right? It seems like reading literature is always one of the first things to go, so I’ve been spending some time reading a number of papers that I had set aside to be read “sometime” since they’ll definitely feature in a background section in my future. I’m quite interested in the evolution of cooperation, and one type of cooperative “game” is the production and use of public goods. A public good is a product that is useful to an organism, but is for some reason physically outside of the organism’s control and so must be shared with surrounding organisms. In the simplest systems, a “tragedy of the commons” scenario can occur in which organisms that don’t […]
The other day, I was reading a paper (paywall) on using graph and network theory to quantify properties of ecological landscapes, by Rayfield et al. It is a review summarizing: what properties of landscape networks we might want to measure, structural levels within networks that we might want to measure these properties at (e.g. node, neighborhood, connected component, etc), and metrics that can be used to measure a given property at a given structural level. The authors found that there was dramatic variation in the number of metrics available in these different categories. I was particularly struck by this comment, offering a potential explanation for the complete lack of component-level route redundancy metrics: “This omission could be attributed to, first, the importation of measures from other disciplines that prioritized network efficiency over network redundancy…”
One of my stepping stones towards becoming an evolutionary biologist was playing with engaging programs that combine evolution and artificial life. Although these “games” are often neither intended for educational or research purposes, I found them instrumental in developing an appreciation for the power and creativity of evolution by natural selection. Here is a collection of my favorites in no particular order: Bitozoa http://www.bpp.com.pl/bitozoa2/bitozoa2.html