Every Friday at Nothing in Biology Makes Sense! our contributors pass around links to new scientific results, or science-y news, or videos of adorable wildlife, that they’re most likely to bring up while waiting in line for a latte.
credit: Rik Panganiban
Massive open online courses (MOOCs) have caught Devin’s eye (@devindrown). This January the Santa Fe Institute is offering an Introduction to Complex Systems Science. You don’t need a science or math background.
Things to think about for New Year’s Resolutions related to health. It’s the little things that matter says Jonathan (@Bonovox1984)
Why not check out what Carl Zimmer on the Loom blog writes about sex differences in spatial abilities over at National Geographic’s Phenomena. Sarah (@sarahmhird) feared this article (Of Men, Navigation, and Zits) was going to be drawn into evolutionary psychology BS but thankfully, Zimmer is smarter than that.
Via Jeremy (@JBYoder) Why not see what makes humans so restless and learn about human migration.This looked like it was going to go into deep adaptationist territory, then all of a sudden actual population geneticists started showing up.
Noah (@NM_Reid) recommends this story on how the tree frog is redefining conventional wisdom about evolution over at the Smithsonian Magazine. He also thought this article on the a biological field station in the Amazon is worth checking out.
They say scariest of the deep sea, but Sarah (@sarahmhird) says coolest monsters, take a look over at the seo companies Smithsonian and decide for yourself.
Review of The Adaptive Landscape in Evolutionary Biology edited by Erik Svensson and Ryan Calsbeek
Have you ever wished you could go back in time to be present at a particular historical event? The 1932 International Congress of Genetics sounds perfect, right? There R. A. Fisher, J. B. S. Haldane, and Sewall Wright all presented papers of their recent research. If you’re a student of population genetics, you probably recognize these names as some of the founders of the field. At this meeting, Wright was asked to condense some of his more technical mathematical framework into a form that was more widely accessible to the audience of biologists. The result was his conceptualization of the Adaptive Landscape where an analogy is made between the fitness of an individual or population and the varied topographic landscape (pictured on the cover of the book). Wright used this metaphor to describe aspects evolutionary dynamics of populations.
The editors of a recent book, The Adaptive Landscape in Evolutionary Biology, gathered together contributions from evolutionary biologists, ecologists, and philosophers to demonstrate the impact that the Adaptive Landscape has had on the field of biology. This book embraces an 80 year old metaphor created by one of the founders of the modern synthesis to explore the breadth and depth of research generated in evolutionary biology. Unlike a recent book addressing aspects of the modern synthesis, Evolution: The Extendend Synthesis (Pigliucci and Müller, 2010) which called for a revolution, Svensson and Calsbeek have assembled authors that explore the innovations and contributions that build upon the fundamental ideas of population genetics and seek to grow the field. Early in this book, Pigliucci asks about the utility of the Adaptive Landscape metaphors, even titling his chapter with the question, “what are they good for?” I think the rest of the book provides a more than sufficient answer to his question.
Evolutionary change by means of Natural Selection needs a couple of things in order to happen: heritability and variation in fitness. That is, offspring need to resemble their parents at least a little (heritability) and individuals need to differ in their survival and offspring production (fitness). We’ll worry about heritability in another post, but variation is something that seems like it might be hard to maintain. Some forms of Natural Selection will reduce variation as more fit individuals become frequent and all the different kinds of less fit individuals are eliminated from the population. However, there is a force, common in nature, which may maintain variation, parasites.
Interactions between hosts and parasites can generate strong selective pressures on each player, especially if your life depends on infecting a host. Often, biologists make an analogy to an arms race where players are developing bigger and better defenses or weapons. Antagonistic interactions may also generate negative frequency dependence where a rare host type is favored because the parasites are adapted to a common type. You can learn more by checking out CJ’s post on the Red Queen Hypothesis or Jeremy’s post on a different coevolutionary puzzle. A key component for maintaining variation via negative frequency dependent selection is specificity. There must variation in the interaction among different host genotypes and parasite genotypes. This is sometimes referred to as a GxG interaction. If parasites can infect all the hosts, there is no specificity. Specificity allows different hosts to be favored over time depending on the composition of the parasite population.
Theoreticians love to use different models of interactions between hosts and parasites, but without empirical evidence, there seems little point. In a recent paper by Rouchet and Vorburger (2012), the authors looked for evidence of just the kind of genetic specificity would result in the maintenance of genetic variation.
Ever want to participate in a journal club, but just can’t seem to find the right group of people locally? Why not find the critical mass you need from colleagues online at other universities? That’s more or less what a group did recently. Last week, Rafael Maia, a PhD candidate at the University of Akron, organized an online journal club for discussing evolutionary biology.
For the first meeting, they discussed a recent Nature paper by Hugall & Stuart-Fox titled “Accelerated speciation in Colour-polymorphic birds.” The discussion was held via Google+ hangouts which worked remarkably well considering the number of participants. Be sure to check back often as they are aiming for meetings every two weeks (or more often).
If you missed the session live, you can see the recorded video by heading over to the Evolutionary Biology Online Journal Club blog.
This post is a guest contribution by Dr. Levi Morran, NIH postdoctoral fellow at Indiana University. Levi studies the role that both coevolutionary relationships and mating systems play in shaping evolutionary trajectories. His research using experimental coevolution to test the Red Queen hypothesis recently appeared in Science and was featured on NPR and the BBC.
The 40 Year-Old Virgin
In the movie, The 40 Year Old Virgin, Steve Carell’s character (the title character) asks a sex education instructor, “Is it true that if you don’t use it, you lose it?” Given the context, I’ll allow you to put the pieces together and figure out just what he was referencing with the question. But, the phrase “use it or lose it” is quite catchy isn’t it?
Surprisingly, the phrase is thought to have some relevance in the field of evolutionary genetics, particularly regarding bacterial genomes. You see, widespread gene loss and genome reduction has been observed in some strains of bacteria, particularly those that specialize in certain environments (Cramer et al. 2011; Ernst et al. 2003; Smith et al. 2006). But, how and why do bacteria “lose it”, and do they lose it because they don’t use it?
This post is a guest contribution by Amy Dapper, the proprietor of Evolve It!, a blog about (sometimes) cool (mostly) science-y things. Amy is a PhD student at Indiana University studying evolutionary theory.
Religious beliefs, or more likely disbelief, tend to be a hot topic on science blogs, particularly those with a evolutionary bend. However, when these topics come up there is often more opinion than science, which is why I was excited to see an research article in last weeks edition of Science titled ‘Analytical Thinking Promotes Religious Disbelief’ . The article, authored by Will M. Gervais and Ara Norenzayan, uses a series of five studies to build a causal link between analytical cognitive processes and religious disbelief. I thought it would be fun to delve into the science behind their audaciously titled article for my guest post here at Nothing in Biology Makes Sense.
The authors approach understanding the cognitive underpinnings of religious belief and disbelief using the dual-process theory of human thought. This theory posits that we use two distinct and separate systems for reasoning. The first, creatively termed System 1, is intuitive and produces a rapid response based only on prior knowledge and experience. Previous research has found that individuals who rely more heavily on this intuitive cognitive system are more likely to believe in supernatural entities, and thus tend to have stronger religious beliefs . On the other hand, System 2 is rational and produces a slower response based upon logic and reasoning that, when employed, often overrides the conclusions of System 1. The authors hypothesize that, in contrast to System 1, this analytical cognitive system promotes religious disbelief.
Conventional wisdom suggests that pathogens and parasites are more rapidly evolving because of various reasons such as short generation time or stronger selection. Yet somehow, they have not completely won the battle against the host. Recently, a theoretical paper on coevolution in Nature caught my eye (Gilman et al., 2012). Here the authors address this paradox: “How do victim species survive and even thrive in the face of a continuous onslaught of more rapidly evolving enemies?”
Instead of treating a coevolutionary interaction between two species as the interaction of only two traits, the authors investigate the nature of an interaction among a suite of traits in each species. It’s not hard to think of a host having a fortress of defenses against attack from a parasite with an arsenal loaded with many weapons.