Search results for "10.03"

Novel sexual dimorphism in a new genus of Bathynellidae from Russia, with a revision of phylogenetic relationships

2019

Bathynellidae is the neglected family of Bathynellacea, a groundwater group of crus- taceans with 33 genera and 107 species described and almost half of them included in the `catch-all¿ genus Bathynella. Due to the morphological homogeneity of the spe- cies, the taxonomic uncertainties have accumulated over time. Therefore, to explore the phylogenetic relationships among taxa, a combined approach using morphologi- cal and molecular data is needed. In this paper, we performed a phylogenetic analysis based on partial sequences of COI and 18S including 30 species of Bathynellidae. This data set represents the most updated one, including a new genus and a new spe- cies (Altainella calcarata gen…

2021

Climate change is having a serious impact on many ecosystems. In the summer of 2018 and 2019, around two thirds of European beech trees were damaged or killed by extreme drought. It is critical to keep these beech woods healthy, as they are central to the survival of over 6,000 other species of animals and plants. The level of damage caused by the drought varied between forests. However, not all the trees in each forest responded in the same way, with severely damaged trees often sitting next to fully healthy ones. This suggests that the genetic make-up of each tree determines how well it can adapt to drought rather than its local environment. To investigate this further, Pfenninger et al. …

Ant recognition cue diversity is higher in the presence of slavemaker ants

2015

Social insect colonies defend themselves from intruders through nestmate recognition, yet the evolution and maintenance of recognition cue diversity is still poorly understood. We compared the recognition cue diversity of 9 populations of Temnothorax longispinosus ant colonies, including populations that harbored the socially parasitic slavemaker ant, Protomognathus americanus. Although ants recognize friends from foe based on recognition cues encoded in their cuticular hydrocarbon profile, which specific compounds are involved in recognition is unknown for most species. We therefore started by statistically identifying 9 putative recognition compounds involved in worker and colony aggressi…

SPECIES RICHNESS WITHIN FAMILIES OF FLOWERING PLANTS

1994

Variation in species and genus richness among families of flowering plants was examined with respect to four classification variables: geographical distribution, growth form, pollination mode, and dispersal mode. Previous studies have estimated rates of species proliferation from age and contemporary diversity. Here we found that the earliest appearances in the fossil record are correlated with contemporary familial species richness, abundance in the fossil record, and the independent variables considered in this analysis. Thus, we believe that the fossil record does not provide reasonable estimates of the ages of families and that the rate of species proliferation cannot be calculated from…

Cuticular hydrocarbon profiles differ between ant body parts: implications for communication and our understanding of CHC diffusion.

2020

Abstract Insect cuticular hydrocarbons (CHCs) serve as communication signals and protect against desiccation. They form complex blends of up to 150 different compounds. Due to differences in molecular packing, CHC classes differ in melting point. Communication is especially important in social insects like ants, which use CHCs to communicate within the colony and to recognize nestmates. Nestmate recognition models often assume a homogenous colony odor, where CHCs are collected, mixed, and redistributed in the postpharyngeal gland (PPG). Via diffusion, recognition cues should evenly spread over the body surface. Hence, CHC composition should be similar across body parts and in the PPG. To te…

Effects of acclimation time and epigenetic mechanisms on growth of Neurospora in fluctuating environments

2017

AbstractReaction norms or tolerance curves have often been used to predict how organisms deal with fluctuating environments. A potential drawback is that reaction norms measured in different constant environments may not capture all aspects of organismal responses to fluctuating environments. We examined growth of the filamentous fungusNeurospora crassain fluctuating temperatures and tested if growth in fluctuating temperatures can be explained simply by growth in different constant temperatures or if more complex models are needed. In addition, as previous studies on fluctuating environments have revealed that past temperatures that organisms have experienced can affect their response to c…

Ecological genomics of adaptation to unpredictability in experimental rotifer populations

2019

AbstractElucidating the genetic basis of phenotypic variation in response to different environments is key to understanding how populations evolve. Facultatively sexual rotifers can develop adaptive responses to fluctuating environments. In a previous evolution experiment, diapause-related traits changed rapidly in response to two selective regimes (predictable vs unpredictable) in laboratory populations of the rotifer Brachionus plicatilis. Here, we investigate the genomic basis of adaptation to environmental unpredictability in these experimental populations. We identified and genotyped genome-wide polymorphisms in 169 clones from both selective regimes after seven cycles of selection usi…

Use of DNA barcoding in the assignment of commercially valuable fish species from Romania

2017

DNA barcoding is a molecular technique frequently used either for biodiversity monitoring and fish conservation or in the identification of the species of origin for raw and processed food from restaurants or fish markets. The most important aspect of this technique is that it works for all stages of life and can be used to distinguish between closely related taxa. Also, the technique has been used to unmask attempts of frauds in fish markets where more desirable and expensive fish are sometimes substituted with lower valued species. Our study aims to test the utility of the COI barcoding gene in the correct identification of several economically and ecologically valuable fish species, and …

Behavioural, ecological, and evolutionary aspects of diversity in frog colour patterns

2016

The role of colours and colour patterns in behavioural ecology has been extensively studied in a variety of contexts and taxa, while almost overlooked in many others. For decades anurans have been the focus of research on acoustic signalling due to the prominence of vocalisations in their communication. Much less attention has been paid to the enormous diversity of colours, colour patterns, and other types of putative visual signals exhibited by frogs. With the exception of some anecdotal observations and studies, the link between colour patterns and the behavioural and evolutionary ecology of anurans had not been addressed until approximately two decades ago. Since then, there has been eve…

Hierarchy is Detrimental for Human Cooperation

2015

Studies of animal behavior consistently demonstrate that the social environment impacts cooperation, yet the effect of social dynamics has been largely excluded from studies of human cooperation. Here, we introduce a novel approach inspired by nonhuman primate research to address how social hierarchies impact human cooperation. Participants competed to earn hierarchy positions and then could cooperate with another individual in the hierarchy by investing in a common effort. Cooperation was achieved if the combined investments exceeded a threshold, and the higher ranked individual distributed the spoils unless control was contested by the partner. Compared to a condition lacking hierarchy, c…