Read by QxMD icon Read

Evolution; International Journal of Organic Evolution

Frederico Henning, Gonzalo Machado-Schiaffino, Lukas Baumgarten, Axel Meyer
Genes of major phenotypic effects and strong genetic correlations can facilitate adaptation, direct selective responses and potentially lead to phenotypic convergence. However, the preponderance of this type of genetic architecture in repeatedly-evolved adaptations remains unknown. Using hybrids between Haplochromis chilotes (thick-lipped) and H. nyererei (thin-lipped) we investigated the genetics underlying hypertrophied lips and elongated heads, traits that evolved repeatedly in cichlids. At least 25 loci of small-to-moderate and mainly additive effects were detected...
February 17, 2017: Evolution; International Journal of Organic Evolution
Aleeza C Gerstein, Heekyung Lim, Judith Berman, Meleah A Hickman
Variation in baseline ploidy is seen throughout the tree of life, yet the factors that determine why one ploidy level is maintained over another remain poorly understood. Experimental evolution studies using asexual fungal microbes with manipulated ploidy levels intriguingly reveals a propensity to return to the historical baseline ploidy, a phenomenon that we term 'ploidy drive'. We evolved haploid, diploid, and polyploid strains of the human fungal pathogen Candida albicans under three different nutrient limitation environments to test whether these conditions, hypothesized to select for low ploidy levels, could counteract ploidy drive...
February 14, 2017: Evolution; International Journal of Organic Evolution
Nicholas J Kooyers, Brooke James, Benjamin K Blackman
Closely related species may evolve to coexist stably in sympatry through niche differentiation driven by in situ competition, a process termed character displacement. Alternatively, past evolution in allopatry may have already sufficiently reduced niche overlap to permit establishment in sympatry, a process called ecological sorting. The relative importance of each process to niche differentiation is contentious even though they are not mutually exclusive and are both mediated via multivariate trait evolution...
February 10, 2017: Evolution; International Journal of Organic Evolution
Piotr K Rowinski, Björn Rogell
Adaptive evolutionary responses are determined by the strength of selection and the amount of genetic variation within traits, however, both are known to vary across environmental conditions. As selection is generally expected to be strongest under stressful conditions, understanding how the expression of genetic variation changes across stressful and benign environmental conditions is crucial for predicting the rate of adaptive change. While theory generally predicts increased genetic variation under stress, previous syntheses of the field has found limited support for this notion...
February 10, 2017: Evolution; International Journal of Organic Evolution
Andrew A Crowl, Cody Myers, Nico Cellinese
The Mediterranean Basin harbors a remarkable amount of biodiversity, a high proportion of which is endemic to this region. Here we present an in-depth study of an angiosperm species complex, in which cryptic taxonomic diversity has been hypothesized. Specifically, we focus on four currently recognized species in the Roucela complex, a well-supported clade in the Campanulaceae/Campanuloideae: Campanula creutzburgii, C. drabifolia, C. erinus, and C. simulans. This study takes a phylogenomic approach, utilizing near-complete plastomes and 130 nuclear loci, to uncover cryptic diversity and test hypotheses regarding hybridization and polyploidy within this clade...
February 10, 2017: Evolution; International Journal of Organic Evolution
Michael S Reichert, Jonas Finck, Bernhard Ronacher
A major challenge in evolutionary biology is explaining the origins of complex phenotypic diversity. In animal communication, complex signals may evolve from simpler signals because novel signal elements exploit pre-existing biases in receivers' sensory systems. Investigating the shape of female preference functions for novel signal characteristics is a powerful, but underutilized, method to describe the adaptive landscape potentially guiding complex signal evolution. We measured female preference functions for characteristics of acoustic appendages added to male calling songs in the grasshopper Chorthippus biguttulus, which naturally produces only simple songs...
February 10, 2017: Evolution; International Journal of Organic Evolution
Josianne Lachapelle, Nick Colegrave
The adaptive function of sex has been extensively studied, while less consideration has been given to the potential downstream consequences of sex on evolution. Here we investigate one such potential consequence, the effect of sex on the repeatability of evolution. By affecting the repeatability of evolution, sex could have important implications for biodiversity, and for our ability to make predictions about the outcome of environmental change. We allowed asexual and sexual populations of Chlamydomonas reinhardtii to evolve in novel environments and monitored both their change in fitness and variance in fitness after evolution...
February 9, 2017: Evolution; International Journal of Organic Evolution
Duong T Nguyen, Jennifer L Morrow, Robert N Spooner-Hart, Markus Riegler
Cardinium and Wolbachia are common maternally inherited reproductive parasites that can co-infect arthropods, yet interactions between both bacterial endosymbionts are rarely studied. For the first time, we report their independent expression of complete cytoplasmic incompatibility (CI) in a co-infected host, and CI in a species of the haplodiploid insect order Thysanoptera. In Pezothrips kellyanus, Cardinium-induced CI resulted in a combination of male development (MD) and embryonic female mortality (FM) of fertilised eggs...
February 9, 2017: Evolution; International Journal of Organic Evolution
Allison J Shultz, Kevin J Burns
Males and females can be under different evolutionary pressures if sexual and natural selection is differentially operating in each sex. As a result, many species have evolved sexual dichromatism, or differences in coloration between sexes. Although sexual dichromatism is often used as an index of the magnitude of sexual selection, sexual dichromatism is a composite trait. Here, we examine the evolution of sexual dichromatism in one of the largest and most ecologically diverse families of birds, the tanagers, using the avian visual perspective and a species-level phylogeny...
February 7, 2017: Evolution; International Journal of Organic Evolution
Johanna Chemnitz, Nadiia Bagrii, Manfred Ayasse, Sandra Steiger
Studying the relationship between parental and mating effort helps us to understand the evolution of parental care and, consequently, has been the subject of many theoretical and empirical investigations. Using burying beetles as a model, we found no correlation between the intensity of a sexual signal (sex pheromone quantity) and the amount of care provided by males. However, males that were given the opportunity to breed and care for young went on to produce a higher amount of their sexual signal and attracted three times more females in the field than control males that were not given the opportunity to breed...
February 1, 2017: Evolution; International Journal of Organic Evolution
Paola Laiolo
Crows, rooks and ravens (Corvus spp.) display marked morphological and voice similarities that have been hypothesised to stem from competitive interactions, as a case of non-aposematic mimicry. Here, I test predictions of the mimicry hypothesis at the macrovolutionary scale, examining whether species morphological and acoustic traits covary with those of coexisting congeners, and whether phenotypic similarity has facilitated the coexistence of related species after secondary contact. Body size and the temporal patterns of the commonest call display high levels of similarity among sympatric species, even after controlling for the effect of shared climate and habitat, and phylogenetic constraints in the production of variation...
February 1, 2017: Evolution; International Journal of Organic Evolution
Hildegard Uecker
Severe environmental change can drive a population extinct unless the population adapts in time to the new conditions ("evolutionary rescue"). How does bi-parental sexual reproduction influence the chances of population persistence compared to clonal reproduction or selfing? In this paper, we set up a one-locus two-allele model for adaptation in diploid species, where rescue is contingent on the establishment of the mutant homozygote. Reproduction can occur by random mating, selfing, or clonally. Random mating generates and destroys the rescue mutant; selfing is efficient at generating it but at the same time depletes the heterozygote, which can lead to a low mutant frequency in the standing genetic variation...
January 31, 2017: Evolution; International Journal of Organic Evolution
Thomas G Aubier, Marianne Elias, Violaine Llaurens, Nicolas Chazot
Species richness varies among clades, yet the drivers of diversification creating this variation remain poorly understood. While abiotic factors likely drive some of the variation in species richness, ecological interactions may also contribute. Here, we examine one class of potential contributors to species richness variation that is particularly poorly understood: mutualistic interactions. We aim to elucidate large-scale patterns of diversification mediated by mutualistic interactions using a spatially-explicit population-based model...
January 27, 2017: Evolution; International Journal of Organic Evolution
Peter C Zee, Gregory J Velicer
Epistatic interactions can greatly impact evolutionary phenomena, particularly the process of adaptation. Here, we leverage four parallel experimentally evolved lineages to study the emergence and trajectories of epistatic interactions in the social bacterium Myxococcus xanthus. A social gene (pilA) necessary for effective group swarming on soft agar had been deleted from the common ancestor of these lineages. During selection for competitiveness at the leading edge of growing colonies, two lineages evolved qualitatively novel mechanisms for greatly increased swarming on soft agar, whereas the other two lineages evolved relatively small increases in swarming...
January 27, 2017: Evolution; International Journal of Organic Evolution
Laurel R Yohe, Ramatu Abubakar, Christina Giordano, Elizabeth Dumont, Karen Sears, Stephen J Rossiter, Liliana M Dávalos
Comparative methods are often used to infer loss or gain of complex phenotypes, but few studies take advantage of genes tightly linked with complex traits to test for shifts in the strength of selection. In mammals vomerolfaction detects chemical cues mediating many social and reproductive behaviors and is highly conserved, but all bats exhibit degraded vomeronasal structures with the exception of two families (Phyllostomidae and Miniopteridae). These families either regained vomerolfaction after ancestral loss, or there were many independent losses after diversification from an ancestor with functional vomerolfaction...
January 27, 2017: Evolution; International Journal of Organic Evolution
Jennifer N Lohr
Aging is a complex phenotype, and the future of our understanding its nature and pathology requires an interdisciplinary approach. Evolutionary biology and theory starting with Fisher, Medawar, Williams and Hamilton provided a solid base for the understanding of how and why aging evolves, based on a decreasing selection pressure with age (Charlesworth 2000). Further theoretical models by Charlesworth and others in the 1990s then generated a deeper understanding of aging as well as solid predictions that could be tested empirically...
January 25, 2017: Evolution; International Journal of Organic Evolution
Valerie J Morley, Paul E Turner
Understanding the dynamics of molecular adaptation is a fundamental goal of evolutionary biology. While adaptation to constant environments has been well characterized, the effects of environmental complexity remain seldom studied. One simple but understudied factor is the rate of environmental change. Here we used experimental evolution with RNA viruses to investigate whether evolutionary dynamics varied based on the rate of environmental turnover. We used whole-genome next-generation sequencing to characterize evolutionary dynamics in virus populations adapting to a sudden versus gradual shift onto a novel host cell type...
January 25, 2017: Evolution; International Journal of Organic Evolution
Caroline E Thomson, Florian Bayer, Nicholas Crouch, Samantha Farrell, Elizabeth Heap, Elizabeth Mittell, Mar Zurita-Cassinello, Jarrod D Hadfield
There is abundant evidence in many taxa for positive directional selection on body size, and yet little evidence for microevolutionary change. In many species, variation in body size is partly determined by the actions of parents, so a proposed explanation for stasis is the presence of a negative genetic correlation between direct and parental effects. Consequently, selecting genes for increased body size would result in a correlated decline in parental effects, reducing body size in the following generation...
January 20, 2017: Evolution; International Journal of Organic Evolution
Adam M Siepielski, Jeremy M Beaulieu
Most species have evolved adaptations to reduce the chances of predation. In many cases adaptations to coexist with one predator generate tradeoffs in the ability to live with other predators. Consequently, the ability to live with one predator may limit the geographic distributions of species, such that adaptive evolution to coexist with novel predators may facilitate range shifts. In a case study with Enallagma damselflies, we used a comparative phylogenetic approach to test the hypothesis that adaptive evolution to live with a novel predator facilitates range size shifts...
January 17, 2017: Evolution; International Journal of Organic Evolution
Alexander Skeels, Marcel Cardillo
The causes of exceptionally high plant diversity in Mediterranean-climate biodiversity hotspots are not fully understood. We asked whether a mechanism similar to the tropical niche conservatism hypothesis could explain the diversity of four large genera (Protea, Moraea, Banksia, and Hakea) with distributions within and adjacent to the Greater Cape Floristic Region (South Africa) or the Southwest Floristic Region (Australia). Using phylogenetic and spatial data we estimated the environmental niche of each species, and reconstructed the mode and dynamics of niche evolution, and the geographic history, of each genus...
January 17, 2017: Evolution; International Journal of Organic Evolution
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"