Although we have a good understanding of how phenotypic plasticity evolves in response to abiotic environments, we know comparatively less about responses to biotic interactions. We experimentally tested how competition and mutualism affected trait and plasticity evolution of pairwise communities of genetically modified brewer's yeast. We quantified evolutionary changes in growth rate, resource use efficiency (RUE), and their plasticity in strains evolving alone, with a competitor, and with a mutualist.
View Article and Find Full Text PDFFunctional traits fall along a continuum from resource conservative to acquisitive and are powerful predictors of the ecological settings necessary for a species to persist and establish. As a consequence, a major problem that functional trait analysis could address is understanding the ecological contexts necessary for the persistence of polyploid plants, because early generation polyploids, or "neopolyploids," are at a high extinction risk. Because neopolyploidy could increase nutrient limitation, growth strategies should shift to accommodate the increased need for resources, but this prediction is untested.
View Article and Find Full Text PDFSpecies interactions shape the evolution of traits, life histories and the pattern of speciation. What is less clear is whether certain types of species interaction are more or less likely to lead to phenotypic divergence among species. We used the brood pollination mutualism between yuccas and yucca moths to test how mutualistic (pollination) and antagonistic (oviposition) traits differ in the propensity to increase phenotypic divergence among pollinator moths.
View Article and Find Full Text PDFThe obligate pollination mutualism between Yucca and yucca moths is a classical example of coevolution. Oviposition and active pollination by female yucca moths occur at night when Yucca flowers are open and strongly scented. Thus, floral volatiles have been suggested as key sensory signals attracting yucca moths to their host plants, but no bioactive compounds have yet been identified.
View Article and Find Full Text PDFBackground: Altica (Coleoptera: Chrysomelidae) is a highly diverse and taxonomically challenging flea beetle genus that has been used to address questions related to host plant specialization, reproductive isolation, and ecological speciation. To further evolutionary studies in this interesting group, here we present a draft genome of a representative specialist, Altica viridicyanea, the first Alticinae genome reported thus far.
Results: The genome is 864.
Insect mutualisms are essential for reproduction of many plants, protection of plants and other insects, and provisioning of nutrients for insects. Disruption of these mutualisms by global change can have important implications for ecosystem processes. Here, we assess the general effects of global change on insect mutualisms, including the possible impacts on mutualistic networks.
View Article and Find Full Text PDFUnderstanding how mutualisms persist over time requires investigations of how mutualist species coevolve and adapt to the interaction. In particular, the key factors in the evolution of mutualisms are the costs and benefits mutualists experience during the interaction. Here, we used a yeast nutritional mutualism to test how mutualists coevolve and adapt in an obligate mutualism.
View Article and Find Full Text PDFMutualisms, or reciprocally beneficial interspecific interactions, constitute the foundation of many ecological communities and agricultural systems. Mutualisms come in different forms, from pairwise interactions to extremely diverse communities, and they are continually challenged with exploitation by nonmutualistic community members (exploiters). Thus, understanding how mutualisms persist remains an essential question in ecology.
View Article and Find Full Text PDFHost plant shifts are a common mode of speciation in herbivorous insects. Although insects can evolve adaptations to successfully incorporate a new host plant, it is becoming increasingly recognized that the gut bacterial community may play a significant role in allowing insects to detoxify novel plant chemical defenses. Here, we examined differences in gut bacterial communities between Altica flea beetle species that feed on phylogenetically unrelated host plants in sympatry.
View Article and Find Full Text PDFPremise: Although polyploidy has been studied since the early 1900s, fundamental aspects of polyploid ecology and evolution remain unexplored. In particular, surprisingly little is known about how newly formed polyploids (neopolyploids) become demographically established. Models predict that most polyploids should go extinct within the first few generations as a result of reproductive disadvantages associated with being the minority in a primarily diploid population (i.
View Article and Find Full Text PDFPremise: Variation in pollen-ovule ratios is thought to reflect the degree of pollen transfer efficiency-the more efficient the process, the fewer pollen grains needed. Few studies have directly examined the relationship between pollen-ovule ratio and pollen transfer efficiency. For active pollination in the pollination brood mutualisms of yuccas and yucca moths, figs and fig wasps, senita and senita moths, and leafflowers and leafflower moths, pollinators purposefully collect pollen and place it directly on the stigmatic surface of conspecific flowers.
View Article and Find Full Text PDFPremise: Polyploidy is known to cause physiological changes in plants which, in turn, can affect species interactions. One major physiological change predicted in polyploid plants is a heightened demand for growth-limiting nutrients. Consequently, we expect polyploidy to cause an increased reliance on the belowground mutualists that supply these growth-limiting nutrients.
View Article and Find Full Text PDFPremise Of The Study: Polyploidy, or whole genome duplication (WGD), is common in plants despite theory suggesting that polyploid establishment is challenging and polyploids should be evolutionarily transitory. There is renewed interest in understanding the mechanisms that could facilitate polyploid establishment and explain their pervasiveness in nature. In particular, premating isolation from their diploid progenitors is suggested to be a crucial factor.
View Article and Find Full Text PDFThe hydrocarbon pattern in the floral scent of Yucca species was found to comprise a group of unbranched, mid-chain alkanes, alkenes, and an alkadiene. In Y. reverchonii, highly dominant (Z)-8-heptadecene is accompanied by (6Z,9Z)-6,9-heptadecadiene and heptadecane as minor components and by traces of other saturated and unsaturated hydrocarbons with similar chain length.
View Article and Find Full Text PDFDivergence in chemosensory traits has been posited as an important component of chemosensory speciation in insects. In particular, chemosensory genes expressed in the peripheral sensory neurons are likely to influence insect behaviors such as preference for food, oviposition sites, and mates. Despite their key role in insect behavior and potentially speciation, the underlying genetic basis for divergence in chemosensory traits remains largely unexplored.
View Article and Find Full Text PDFPolyploidy is a common mode of speciation that can have far-reaching consequences for plant ecology and evolution. Because polyploidy can induce an array of phenotypic changes, there can be cascading effects on interactions with other species. These interactions, in turn, can have reciprocal effects on polyploid plants, potentially impacting their establishment and persistence.
View Article and Find Full Text PDFCovariation among organismal traits is nearly universal, occurring both within and among species (static and evolutionary allometry, respectively). If conserved developmental processes produce similarity in static and evolutionary allometry, then when species differ in development, it should be expressed in discordance between allometries. Here, we investigate whether rapidly evolving developmental processes result in discordant static and evolutionary allometries attributable to trade-offs in resource acquisition, allocation, or growth across 30 species of aquatic beetles.
View Article and Find Full Text PDFHost shifts and subsequent adaption to novel host plants are important drivers of speciation among phytophagous insects. However, there is considerably less evidence for host plant-mediated speciation in the absence of a host shift. Here, we investigated divergence of two sympatric sister elm leaf beetles, Pyrrhalta maculicollis and P.
View Article and Find Full Text PDFMoyamoya disease is a rare progressive cerebrovascular disorder that can be congenital or acquired and involves progressive stenosis and occlusion of cerebral arteries. The brain through compensatory angeogenesis then attempts to compensate for ischemia by producing a local network of tiny blood vessels, which appear cloud-like on angiograms. Consistent with multifocal or diffuse areas of ischemia, people with moyamoya often have multiple areas of cognitive impairment.
View Article and Find Full Text PDFWhole-genome duplication (polyploidy) occurs frequently and repeatedly within species, often forming new lineages that contribute to biodiversity, particularly in plants. Establishment and persistence of new polyploids may be thwarted by competition with surrounding diploids; however, climatic niche shifts, where polyploids occupy different niches than diploid progenitors, may help polyploids overcome this challenge. We tested for climatic niche shifts between cytotypes using a new ordination approach and an unprecedentedly large data set containing young, conspecific diploids and polyploids.
View Article and Find Full Text PDFTrends Ecol Evol
February 2014
Coevolutionary diversification is cited as a major mechanism driving the evolution of diversity, particularly in plants and insects. However, tests of coevolutionary diversification have focused on elucidating macroevolutionary patterns rather than the processes giving rise to such patterns. Hence, there is weak evidence that coevolution promotes diversification.
View Article and Find Full Text PDFThe Test of Memory Malingering (TOMM) is a measure of test-taking effort that has traditionally been utilized with adults but more recently has demonstrated utility with children. The purpose of this study was to investigate whether commonly used neuropsychological measures can be used as embedded measures in detecting effort during testing. Participants (N = 75) who completed neuropsychological evaluations including the TOMM, Wechsler Intelligence Scale for Children-Fourth Edition (WISC-IV) Digit Span, Children's Memory Scale (CMS) Verbal Memory, and other neuropsychological measures were divided into two groups: Optimal Effort and Suboptimal Effort, based on their TOMM Trial 2 scores.
View Article and Find Full Text PDFFlorivores are present in many pollination systems and can have direct and indirect effects on both plants and pollinators. Although the impact of florivores are commonly examined in facultative pollination mutualisms, their effects on obligate mutualism remain relatively unstudied. Here, we used experimental manipulations and surveys of naturally occurring plants to assess the effect of florivory on the obligate pollination mutualism between yuccas and yucca moths.
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