The Amazon basin is host to numerous arthropod-borne viral pathogens that cause febrile disease in humans. Among these, Oropouche orthobunyavirus (OROV) is a relatively understudied member of the Peribunyavirales that causes periodic outbreaks in human populations in Brazil and other South American countries. Although several studies have described the genetic diversity of the virus, the evolutionary processes that shape the viral genome remain poorly understood. Here we present a comprehensive study...
Wed Jun 26, 2019 03:00
Errors in gene transcription can be costly, and organisms have evolved to prevent their occurrence or mitigate their costs. The simplest interpretation of the drift barrier hypothesis suggests that species with larger population sizes would have lower transcriptional error rates. However, Escherichia coli seems to have a higher transcriptional error rate than species with lower effective population sizes, e.g. Saccharomyces cerevisiae. This could be explained if selection in E. coli were strong enough...
Wed Jun 26, 2019 03:00
Male genital structures are among the most rapidly evolving morphological traits and are often the only features that can distinguish closely related species. This process is thought to be driven by sexual selection and may reinforce species separation. However, while the genetic basis of many phenotypic differences have been identified, we still lack knowledge about the genes underlying evolutionary differences in male genital organs and organ size more generally. The claspers (surstyli) are periphallic...
Wed Jun 26, 2019 03:00
Standard models of sex chromosome evolution propose that recombination suppression leads to the degeneration of the heterogametic chromosome, as is seen for the Y chromosome in mammals and the W chromosome in most birds. Unlike other birds, paleognaths (ratites and tinamous) possess large non- degenerate regions on their sex chromosomes (PARs or pseudoautosomal regions). It remains unclear why these large PARs are retained over more than 100 MY, and how this retention impacts the evolution of sex...
Wed Jun 26, 2019 03:00
Major shifts in life history evolution often coincide with other evolutionary phenomena, such as changes in sexual selection, parent-offspring conflict, and speciation. However, we rarely understand the causative links between correlated patterns of diversification or the tipping points that initiate changes with cascading effects. We investigated livebearing fishes with repeated transitions from pre- to post-fertilization maternal provisioning and correlated mating system evolution to identify the...
Wed Jun 26, 2019 03:00
Since its inception in 1973 the slightly deleterious model of molecular evolution, aka the Nearly Neutral Theory of molecular evolution, remains a central model to explain the main patterns of DNA polymorphism in natural populations. This is not to say that the quantitative fit to data is perfect. In a recent study Castellano et al. (2018) used polymorphism data from D. melanogaster to test whether, as predicted by the Nearly Neutral Theory, the proportion of effectively neutral mutations depends...
Wed Jun 26, 2019 03:00
BackgroundIn separate literatures, biologists have marshaled theoretical and empirical support for theories that a variant can be selected to (1) induce suicide by moribund or otherwise stressed holders; (2) induce suicide by a holder with low productive or reproductive potential; (3) impose senescence upon a chronologically old holder; and (4) reduce the yield of a holder with low genetic heterozygosity. High stress, moribundity, low productive and reproductive potential, high chronological age,...
Wed Jun 26, 2019 03:00
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