What’s wrong with a little sex?

In many species, most (or all) offspring are produced by sexual means. However, theory suggests that selection should often favour the evolution of species in which a small fraction of offspring are produced sexually, and the rest are produced asexually. Here, we present the analysis of a model that may help to resolve this paradox. We show that, when heterozygote advantage is in force, members of species in which sex is rare will tend to produce poorly adapted offspring when they mate. This problem should be less severe in species where most offspring are produced by sexual means. As a consequence, once the rate of sexual reproduction becomes sufficiently rare, the benefits of sex may vanish, leading to the evolution of obligate asexuality. Substantial benefits of sexual reproduction may tend to accrue only if a large proportion of offspring are produced sexually. We suggest that similar findings are likely in the case of epistatic interactions between loci.     

What's wrong with correlative experiments?

Here, we make a case for multivariate measurements in cell biology with minimal perturbation. We discuss how correlative data can identify cause-effect relationships in cellular pathways with potentially greater accuracy than conventional perturbation studies.     

What's wrong with novel ecosystems,really?

The novel ecosystems concept has gained much traction in the restoration community. It has also drawn the ire of several prominent ecologists and is the focus of an ongoing debate. We consider three key aspects of this debate: irreversible thresholds, non‐native species, and the hybrid state. Irreversible thresholds have been acknowledged in restoration for years, but predicting when a threshold will be crossed and the degree of reversibility is problematic. Oftentimes reversibility is a function of multiple factors, such as cost and public support. In this sense, a novel ecosystem is not an alternate state but a decision. The need for pragmatism regarding control of non‐natives has also long been recognized in restoration circles. Proponents of the novel ecosystem idea adopt this pragmatism by recommending that management decisions be based on impacts conferred by species in altered ecosystems, regardless of their origin. The concept of a hybrid state has proven difficult to operationalize. We suggest that rather than trying to identify the boundary between hybrid and novel states, ecosystems exist on a gradient of alteration. We offer a decision tree for restoration action that integrates aspects of novel ecosystems with other perspectives in modern restoration ecology. We conclude that the idea of novel ecosystems, though not perfect, deserves a place under the “big tent” of restoration that includes efforts to return fully to a reference state, as well as strategies for reinstating lost ecological processes and enhancing ecosystem services in transformed landscapes where such a return is deemed infeasible.     

PtdIns5P: a little phosphoinositide with big functions?

Phosphoinositides are minor constituents of cell membranes playing a critical role in the regulation of many cellular functions. Recent discoveries indicate that mutations in several phosphoinositide kinases and phosphatases generate imbalances in the levels of phosphoinositides, thereby leading to the development of human diseases. Although the roles of phosphoinositide 3-kinase products and PtdIns(4,5)P2 were largely studied these last years, the potential role of phosphatidylinositol monophosphates as direct signalling molecules is just emerging. PtdIns5P, the least characterized phosphoinositide, appears to be a new player in cell regulation. This review will summarize the current knowledge on the mechanisms of synthesis and degradation of PtdIns5P as well as its potential roles.