To be or not to be in the nucleolus

Compartmentalization has long been known to have a key role in regulation of cellular processes. By keeping enzymes and regulatory complexes in compartments where the delivery of substrate or exit of product is controlled, competing reactions can occur simultaneously in different parts of the cell. Moreover, spatial confinement facilitates the working of molecules participating in reaction chains and is crucial for coupling unfavourable with energetically favourable chemical reactions. Although in many cases intracellular compartmentalization relies on boundaries imposed by membranes, several non-membrane-bounded compartments exist in eukaryotic cells. One of these, the nucleolus, has recently attracted much attention. The emerging view is that molecular confinement in the nucleolus actively contributes to the control of cellular survival and proliferation.     

To be or not to be a good social partner?

Cooperation based in mutual benefit provides a perfect scenario to start selfish behaviors aimed to obtain greater benefit at the expense of the partner. Here we investigate if mutual benefit cooperation can be stable between individuals that cooperate with kindness (good partners) or if they will be displaced by other individuals that try to obtain more benefit with less cost (bad partners). Our model assumes an asymmetry between partners in such a way that one of them (actor) proposes the cooperation whereas the other (receiver) always accepts the offer. It also assumes that actors can choose the partner on the basis of their past experiences with the potential partners. With the help of a simple two-locus mathematical model we show that not only the gene that conditions the actor preference to choose good partners can increase in frequency but also the gene responsible of the good partner behavior.     

To be or not to be a hamlet pair in sympatry

Recent adaptive radiations, such as the fringillid finches on the Galapagos archipelago or the cichlid fishes in the East African Great Lakes, are invaluable model systems for evolutionary and ecological research. Puebla et al. , in this issue of Molecular Ecology , have established a group of colourful coral reef fishes from the Caribbean sea for studying the early phases of species formation in a marine adaptive radiation. It appears that local evolutionary processes are important in this system, which might have even triggered in situ speciation.     

Invading a mutualistic network: to be or not to be similar

Biological invasion remains a major threat to biodiversity in general and a disruptor to mutualistic interactions in particular. While a number of empirical studies have directly explored the role of invasion in mutualistic pollination networks, a clear picture is yet to emerge and a theoretical model for comprehension still lacking. Here, using an eco‐evolutionary model of bipartite mutualistic networks with trait‐mediated interactions, we explore invader trait, propagule pressure, and network features of recipient community that contribute importantly to the success and impact of an invasion. High level of invasiveness is observed when invader trait differs from those of the community average, and level of interaction generalization equals to that of the community average. Moreover, multiple introductions of invaders with declining propagules enhance invasiveness. Surprisingly, the most successful invader is not always the one having the biggest impact on the recipient community. The network structure of recipient community, such as nestedness and modularity, is not a primary indicator of its invasibility; rather, the invasibility is best correlated with measurements of network stability such as robustness, resilience, and disruptiveness (a measure of evolutionary instability). Our model encompasses more general scenarios than previously studied in predicting invasion success and impact in mutualistic networks, and our results highlight the need for coupling eco‐evolutionary processes to resolve the invasion dilemma.