An evolutionary process is reflected in the sequence of changes through time of any trait (e.g. morphological, molecular). Yet, a better understanding of evolution would be procured by characterizing correlated evolution, or when two or more evolutionary processes interact. A wide range of parametric methods have previously been proposed to detect correlated evolution but they often require significant computing time as they rely on the estimation of many parameters. Here we propose a minimal likelihood...
Sun Sep 06, 2020 03:00
What determines genetic diversity and how it connects to the various biological traits is unknown. In this work, we offer answers to these questions. By comparing genetic variation of 14,671 mammalian gene trees with thousands of individual genomes of human, chimpanzee, gorilla, mouse and dog/wolf, we found that intraspecific genetic diversity is determined by long-term molecular evolutionary rates, rather than de novo mutation rates. This relationship was established during the early stage of mammalian...
Sun Sep 06, 2020 03:00
While the majority of Drosophila species lay eggs onto fermented fruits, females of D. suzukii pierce the skin and lay eggs into ripening fruits using their serrated ovipositors. The changes of oviposition site preference must have accompanied this niche exploitation. In this study, we established an oviposition assay to investigate the effects of commensal microbes deposited by conspecific and heterospecific individuals, and showed that presence of microbes on the oviposition substrate enhances...
Sat Sep 05, 2020 03:00
Coral reefs are the epitome of species diversity rivaled only by tropical rainforests on land. Yet, the number of described scleractinian coral species, the framework-builders of coral reefs, remains moderate by comparison. DNA sequencing studies are challenging this notion by uncovering a wealth of "cryptic diversity", but the ecological relevance of this diversity remains largely unknown. Here, we present a comprehensive case study of one of the most geographically and environmentally ubiquitous...
Sat Sep 05, 2020 03:00
The Pleistocene glacial cycles had a profound impact on the ranges and genetic make-up of organisms. Whilst it is clear that the current contact zones between sister taxa are secondary and have formed during the last interglacial, it is unclear when the taxa involved began to diverge. Previous estimates are unreliable given the stochasticity of genetic drift and the contrasting effects of incomplete lineage sorting and gene flow on gene divergence. We use genome-wide transcriptome data to estimate...
Sat Sep 05, 2020 03:00
The rate at which plants grow is a major functional trait in plant ecology. However, little is known about its evolution in natural populations. Here, we investigate evolutionary and environmental factors shaping variation in the growth rate of Arabidopsis thaliana. We used plant diameter as a proxy to monitor plant growth over time in environments that mimicked latitudinal differences in the intensity of natural light radiation, across a set of 278 genotypes sampled within four broad regions, including...
Sat Sep 05, 2020 03:00
Environmental features can alter the behaviours and phenotypes of organisms and populations evolving within them including the dynamics between natural and sexual selection. Experimental environmental manipulation, particularly when conducted in experiments where the dynamics of the purging of deleterious alleles are compared, has demonstrated both direct and indirect effects on the strength and direction of selection. However, many of these experiments are conducted with fairly simplistic environments...
Sat Sep 05, 2020 03:00
Eutherian (placental) mammals exhibit great differences in the degree of placental invasion into the maternal endometrium, with humans being on the most invasive end. Previously, we have shown that these differences in invasiveness is largely controlled by the stromal fibroblasts of the maternal endometrium, with secondary effect on stroma of other tissues resulting in correlated differences in cancer malignancy. Here, we present a statistical investigation of the second dogma linking the phenotypic...
Sat Sep 05, 2020 03:00
New lineages can arise through mosaic evolution of conserved, ancestral traits, and newly evolved, derived traits. Unraveling the origin of molecular pathways underlying the evolution of adaptive traits is essential for understanding how new lineages emerge. Here, we investigated the evolutionary divergence of sex pheromone communication from moths (mostly nocturnal) to butterflies (mostly diurnal) that occurred ~98 million years ago. In moths, females typically emit pheromones to attract male mates,...
Sat Sep 05, 2020 03:00
Androdioecy (the coexistence of males and hermaphrodites) is a rare mating system for which the evolutionary dynamics are poorly understood. Here we study the only presumed case of androdioecy in insects, found in the cottony cushion scale, Icerya purchasi. In this species, female-like hermaphrodites have been shown to produce sperm and self-fertilize. However, rare males are sometimes observed too. In a large population-genetic analysis, we show for the first time that although self-fertilization...
Sat Sep 05, 2020 03:00
Reticulate evolutionary events are hallmarks of plant phylogeny, and are increasingly recognized as common occurrences in other branches of the Tree of Life. However, inferring the evolutionary history of admixed lineages presents a difficult challenge for systematists due to genealogical discordance caused by both incomplete lineage sorting (ILS) and hybridization. Methods that accommodate both of these processes are continuing to be developed, but they often do not scale well to larger numbers...
Fri Sep 04, 2020 03:00
X and Y chromosomes are usually derived from a pair of homologous autosomes, which then diverge from each other over time. Although Y-specific features have been characterized in sex chromosomes of various ages, the earliest stages of Y chromosome evolution remain elusive. In particular, we do not know whether early stages of Y chromosome evolution consist of changes to individual genes or happen via chromosome-scale divergence from the X. To address this question, we quantified divergence between...
Fri Sep 04, 2020 03:00
Given the importance of DNA methylation in protection of the genome against transposable elements and transcriptional regulation in other taxonomic groups, the diversity in both levels and patterns of DNA methylation in the insects raises questions about its function and evolution. We show that the maintenance DNA methyltransferase, DNMT1, affects meiosis and is essential to fertility in milkweed bugs, Oncopeltus fasciatus, while DNA methylation is not required in somatic cells. Our results support...
Fri Sep 04, 2020 03:00
Independent origins of sociality in bees and ants are associated with independent expansions of the odorant receptor (OR) gene family. In ants, one clade within the OR gene family, the 9-exon subfamily, has dramatically expanded. These receptors detect cuticular hydrocarbons (CHCs), key social signaling molecules in insects. It is unclear to what extent 9-exon OR subfamily expansion is associated with the independent evolution of sociality across Hymenoptera, warranting studies of taxa with independently...
Fri Sep 04, 2020 03:00
Many enveloped viruses such as HIV have evolved to transmit by two infection modes: cell-free infection and cell-to-cell spread. Cell-to-cell spread is highly efficient as it involves directed viral transmission from the infected to the uninfected cell. In contrast, cell-free infection relies on chance encounters between the virion and cell. Despite the higher efficiency of cell-to-cell spread, there is substantial transmission by cell-free infection in conjunction with cell-to-cell spread. A possible...
Fri Sep 04, 2020 03:00
Insects and other arthropods utilise external sensory structures for mechanosensory, olfactory and gustatory reception. These sense organs have characteristic shapes related to their function, and in many cases are distributed in a fixed pattern so that they are identifiable individually. In Drosophila melanogaster, the identity of sense organs is regulated by specific combinations of transcription factors. In other arthropods, however, sense organ subtypes cannot be linked to the same code of gene...
Fri Sep 04, 2020 03:00
Sponges live in symbioses with microbes that allow the hosts to exploit otherwise inaccessible resources. Given the potential of microbiomes to unlock new niche axes for the hosts, microbiomes may facilitate evolutionary innovation in the ecology of sponges. However, the hypothesis that ecological diversification evolves via the microbiome among multiple, closely related sponge species living in sympatry is yet untested. Here, we provide the first test of this hypothesis within Ircinia, a genus possessing...
Fri Sep 04, 2020 03:00
Molecular analyses of closely related taxa have increasingly revealed the importance of higher-order genetic interactions in explaining the observed pattern of reproductive isolation between populations. Indeed, both empirical and theoretical studies have linked the process of speciation to complex genetic interactions. Gene Regulatory Networks (GRNs) capture the inter-dependencies of gene expression and encode information about an individuals phenotype and development at the molecular level. As...
Fri Sep 04, 2020 03:00
Inferring the demographic history of species is one of the greatest challenges in populations genetics. This history is often represented as a history of size changes, thus ignoring population structure. Alternatively, structure is defined a priori as a population tree and not inferred. Here we propose a framework based on the IICR (Inverse Instantaneous Coalescence Rate), which can be estimated using the PSMC method of Li and Durbin (2011) for a single diploid individual. For an isolated population,...
Fri Sep 04, 2020 03:00
Deeply divergent mitochondrial genomes can reveal hidden diversity within species, however robust assessments of diversity require corroborative divergence in the nuclear genome. Previous phylogeographic analysis of the Common Blue butterfly (Polyommatus icarus) revealed a deeply divergent mitotype in Europe. Here, we reconstruct the phylogeography of this butterfly in the British Isles using both mitochondrial and nuclear DNA. We found strong geographical structuring of three distinct CO1 mitotypes...
Sun Sep 06, 2020 03:00
BackgroundWe compare life histories and selection forces among chimpanzees and human subsistence societies in order to identify the age-specific vital rates that best explain fitness variation, selection pressures and species divergence. MethodsWe employ Life Table Response Experiments that quantify vital rate contributions to population growth rate differences. Although widespread in ecology, these methods have not been applied to human populations or to look at species differences among humans...
Sun Sep 06, 2020 03:00
Selection against severe mitochondrial mutations is facilitated by germline processes, lowering the risk of genetic diseases. How selection works is disputed: experimental data are conflicting and previous modelling work has not clarified the issues. Here we develop computational and evolutionary models that compare the outcome of selection at the level of individuals, cells and mitochondria. Using realistic de novo mutation rates and germline development parameters, the evolutionary model accurately...
Thu Sep 03, 2020 03:00
The novel Coronavirus from Wuhan China discovered in December 2019 (nCOV-2019) has since developed into a global epidemic with major concerns about the possibility of the virus evolving into something even more sinister. In the present study we constructed the phylo-geo-network of nCOV-2019 genomes from across India to understand the viral evolution in the country. A total of 611 genomes full length genomes were extracted from different states of India from the EpiCov repository of GISAID initiative...
Thu Sep 03, 2020 03:00
Hybridization of closely related plant species is frequently connected to endosperm arrest and seed failure, for reasons that remain to be identified. In this study, we investigated the molecular events accompanying seed failure in hybrids of the closely related species pair Capsella rubella and C. grandiflora. Mapping of QTLs for the underlying cause of hybrid incompatibility in Capsella revealed three QTLs that were close to pericentromeric regions. This prompted us to investigate whether there...
Thu Sep 03, 2020 03:00
Δεν υπάρχουν σχόλια:
Δημοσίευση σχολίου