sábado, 29 de enero de 2011

Compilado AZyNE 29-01

The Newest Synthesis: Understanding the Interplay of Evolutionary and Ecological Dynamics, Science

Excerpt: The effect of ecological change on evolution has long been a focus of scientific research. The reverse"how evolutionary dynamics affect ecological traits"has only recently captured our attention, however, with the realization that evolution can occur over ecological time scales. This newly highlighted causal direction and the implied feedback loop"eco-evolutionary dynamics"is invigorating both ecologists and evolutionists and blurring the distinction between them.

Swarm intelligence in plant roots, Trends in Ecology & Evolution

Excerpt: (...) swarm intelligence occurs when two or more individuals independently, or at least partly independently, acquire information that is processed through social interactions and is used to solve a cognitive problem in a way that would be impossible for isolated individuals. We propose at least one example of swarm intelligence in plants: coordination of individual roots in complex root systems.

  • Source: Swarm intelligence in plant roots, František Baluška, Simcha Lev-Yadun, Stefano Mancuso, DOI: 10.1016/j.tree.2010.09.003, Trends in Ecology & Evolution, Volume 25, Issue 12, 682-683, 2010/12

Primitive agriculture in a social amoeba, Nature

Excerpt: Here we show that the social amoeba Dictyostelium discoideum has a primitive farming symbiosis that includes dispersal and prudent harvesting of the crop. About one-third of wild-collected clones engage in husbandry of bacteria. Instead of consuming all bacteria in their patch, they stop feeding early and incorporate bacteria into their fruiting bodies. They then carry bacteria during spore dispersal and can seed a new food crop, which is a major advantage if edible bacteria are lacking at the new site.

Infectious moods: How bugs control your mind, New Scientist

Excerpt: Now it seems the immune system, and infections that stimulate it, can influence our moods, memory and ability to learn. Some strange behaviours, such as obsessive compulsive disorder, may be triggered by infections, and the immune system may even shape our basic personalities, such as how anxious or impulsive we are.

Morphological change in machines accelerates the evolution of robust behavior, PNAS

Excerpt: Most animals exhibit significant neurological and morphological change throughout their lifetime. No robots to date, however, grow new morphological structure while behaving. This is due to technological limitations but also because it is unclear that morphological change provides a benefit to the acquisition of robust behavior in machines. Here I show that in evolving populations of simulated robots, if robots grow from anguilliform into legged robots during their lifetime in the early stages of evolution, and the anguilliform body plan is gradually lost during later stages of evolution, gaits are evolved for the final, legged form of the robot more rapidly"and the evolved gaits are more robust"compared to evolving populations of legged robots that do not transition through the anguilliform body plan.

Complexity through Recombination: From Chemistry to Biology, Entropy

Abstract: Recombination is a common event in nature, with examples in physics, chemistry, and biology. This process is characterized by the spontaneous reorganization of structural units to form new entities. Upon reorganization, the complexity of the overall system can change. In particular the components of the system can now experience a new response to externally applied selection criteria, such that the evolutionary trajectory of the system is altered. The link between chemical and biological forms of recombination is explored. (...) The results underscore the importance of recombination in the origins of life on the Earth and its subsequent evolutionary divergence.

Mating strategies in primates: A game theoretical approach to infanticide, Journal of Theoretical Biology

Excerpt: Infanticide by newly immigrated or newly dominant males is reported among a variety of taxa, such as birds, rodents, carnivores and primates. Here we present a game theoretical model to explain the presence and prevalence of infanticide in primate groups. We have formulated a three-player game involving two males and one female and show that the strategies of infanticide on the males' part and polyandrous mating on the females' part emerge as Nash equilibria that are stable under certain conditions [...] These conclusions are confirmed by observations in the wild. These conclusions are confirmed by observations in the wild.

Peer review: Trial by Twitter, Nature

Summary: Blogs and tweets are ripping papers apart within days of publication, leaving researchers unsure how to react.

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