Search results for "Reproductive Isolation"
showing 10 items of 72 documents
Sex-pairing pheromones and reproductive isolation in three sympatric Cornitermes species (Isoptera, Termitidae, Syntermitinae)
2011
International audience; The species-specificity of pairing has been studied in three sympatric Neotropical termites: Cornitermes bequaerti, Cornitermes cumulans and Cornitermes silvestrii (Termitidae, Syntermitinae). Bioassays showed that sex attraction was highly species-specific between C. bequaerti and C cumulans but not between C. cumulans and C. silvestrii. The sex-pairing pheromone of the three species is secreted by the tergal glands of female alates. It consists of a common compound (3Z,6Z,8E)-dodeca-3,6,8-trien-1-ol. In C. bequaerti, this polyunsaturated alcohol is the only compound of the sex-pairing pheromone, whereas it is associated with the oxygenated sesquiterpene (E)-nerolid…
Sexual and postmating reproductive isolation between allopatric Drosophila montana populations suggest speciation potential
2011
This work was funded by a European Commission Research Training Grant RTN2-2001-00049, the Centre of Excellence for Evolutionary Research at the University of Jyväskylä and a Marie Curie Initial Training Network, ‘Understanding the evolutionary origin of biological diversity’ (ITN-2008-213780 SPECIATION) Background: Widely distributed species with populations adapted to different environmental conditions can provide valuable opportunities for tracing the onset of reproductive incompatibilities and their role in the speciation process. Drosophila montana, a D. virilis group species found in high latitude boreal forests in Nearctic and Palearctic regions around the globe, could be an excellen…
Size‐selective harvesting fosters adaptations in mating behaviour and reproductive allocation, affecting sexual selection in fish
2019
The role of sexual selection in the context of harvest-induced evolution is poorly understood. However, elevated and trait-selective harvesting of wild populations may change sexually selected traits, which in turn can affect mate choice and reproduction. We experimentally evaluated the potential for fisheries-induced evolution of mating behaviour and reproductive allocation in fish. We used an experimental system of zebrafish (Danio rerio) lines exposed to large, small or random (i.e. control) size-selective mortality. The large-harvested line represented a treatment simulating the typical case in fisheries where the largest individuals are preferentially harvested. We used a full factoria…
Influence of microbial symbionts on insect pheromones
2018
Covering: up to 2018 Pheromones serve as chemical signals between individuals of the same species and play important roles for mate localization and mate choice as well as other social interactions in insects. A growing body of literature indicates that microbial symbionts can modulate their hosts' chemical profiles, mate choice decisions and social behavior. This modulation can occur by the direct biosynthesis of pheromone components or the provisioning of precursors, or through general changes in the metabolite pool of the host and its resource allocation into pheromone production. Here we review and discuss the contexts in which microbial modulation of intraspecific communication in inse…
Reproductive isolation among allopatric Drosophila montana populations
2014
An outstanding goal in speciation research is to trace the mode and tempo of the evolution of barriers to gene flow. Such research benefits from studying incipient speciation, in which speciation between populations has not yet occurred, but where multiple potential mechanisms of reproductive isolation (RI: i.e., premating, postmating-prezygotic (PMPZ), and postzygotic barriers) may act. We used such a system to investigate these barriers among allopatric populations of Drosophila montana. In all heteropopulation crosses we found premating (sexual) isolation, which was either symmetric or asymmetric depending on the population pair compared. Postmating isolation was particularly strong in c…
DNA content in nine species of Nematocera with special reference to the sibling species of the Anopheles maculipennis group and the Culex pipiens gro…
1972
DNA values were determined for the nine species: Telmatoscopus meridionalis (family Psychodidae), Dixa obscura (family Dixidae), and Culiseta litorea, Culex pipiens, Aedes caspius, Anopheles labranchiae, Anopheles atroparvus, Anopheles stephensi, and Anopheles freeborni (family Culicidae). The DNA content indicated that the species could be divided into three categories: The Culex group with Culex pipiens, Culiseta litorea and Aedes caspius containing 1.02, 0.92 and 0.99 pg DNA in the haploid set, the Anopheles group including the four Anopheles species A. labranchiae, A. atroparvus, A. stephensi, A. freeborni and Telmatoscopus meridionalis with 0.23, 0.24, 0.24, 0.29 and 0.24 pg DNA and th…
Incipient speciation in Drosophila melanogaster involves chemical signals.
2012
WOS: 000300572900001; International audience; The sensory and genetic bases of incipient speciation between strains of Drosophila melanogaster from Zimbabwe and those from elsewhere are unknown. We studied mating behaviour between eight strains - six from Zimbabwe, together with two cosmopolitan strains. The Zimbabwe strains showed significant sexual isolation when paired with cosmopolitan males, due to Zimbabwe females discriminating against these males. Our results show that flies' cuticular hydrocarbons (CHs) were involved in this sexual isolation, but that visual and acoustic signals were not. The mating frequency of Zimbabwe females was highly significantly negatively correlated with t…
The benefits of interpopulation hybridization diminish with increasing divergence of small populations.
2012
Interpopulation hybridization can increase the viability of small populations suffering from inbreeding and genetic drift, but it can also result in outbreeding depression. The outcome of hybridization can depend on various factors, including the level of genetic divergence between the populations, and the number of source populations. Furthermore, the effects of hybridization can change between generations following the hybridization. We studied the effects of population divergence (low vs. high level of divergence) and the number of source populations (two vs. four source populations) on the viability of hybrid populations using experimental Drosophila littoralis populations. Population v…
1993
Biology tells us about the processes and mechanisms which are able to explain effectively the changes occurring in organisms and species. Palaeontology, with the temporal dimension at its disposal, adds to this data which are indispensable for our understanding of speciation and of the patterns and rhythms of evolutionary change. Only through this we are able to observe the historical development of the evolution, of the living world as it took place through geological time. Based on data obtained from other branches of the earth sciences, palaeontology is able to evaluate the external constraints which frequently act at random on the living organism and which control the formation of new s…
1993
The history of life may be compared to a huge cable enclosing as many strands as there are fossil and present species. The biosphere, with its 2 million species, would then correspond to a transverse section through this cable.