Search results for " Systematics"
showing 10 items of 6576 documents
Strategic adjustments in sperm production within and between two island populations of house mice
2012
Sperm production is physiologically costly. Consequently, males are expected to be prudent in their sperm production, and tailor their expenditure according to prevailing social conditions. Differences in sperm production have been found across island populations of house mice that differ in the level of selection from sperm competition. Here, we determined the extent to which these differences represent phenotypic plasticity and/or population divergence in sperm production. We sourced individuals from two populations at the extreme levels of sperm competition, and raised them under common-garden conditions while manipulating the social experience of developing males. Males from the high-sp…
Incorporating spatial structure and stochasticity in endangered Bonelli’s eagle’s population models: implications for conservation and management
2008
Population models have played a chief role informing management decisions for the endangered Bonelli’s eagle (Aquila fasciata) in Spain. In this paper, we incorporate spatial structure and stochasticity in the construction of individual-based metapopulation models, and use these models to explore the effects of possible management actions on the persistence of the species in Spain. To build the models we used data on seven sub-populations that have experienced different trends in the last decades, and we introduced new estimates of pre-adult survival rate. The elasticity analysis of our models showed that when the interchange of individuals among sub-populations is taken into account, pre-a…
The effects of grazing history, soil properties and stand structure on the communities of saprotrophic fungi in wood-pastures
2022
Wood-pastures are threatened anthropogenic biotopes that provide habitat for an extensive group of species. Here we studied the effect of management, grazing intensity, time since abandonment, historical land-use intensity, soil properties and stand conditions on communities of saprotrophic fungi in wood-pastures in Central Finland. We found that the proportion of broadleaved trees and soil pH are the major drivers in the communities of saprotrophic fungi in these boreal wood-pastures. In addition, tree species richness, soil moisture, historical land-use intensity and time since abandonment affected the communities of saprotrophic fungi. Current management or grazing intensity did not have…
The Inactivation Principle: Mathematical Solutions Minimizing the Absolute Work and Biological Implications for the Planning of Arm Movements
2008
An important question in the literature focusing on motor control is to determine which laws drive biological limb movements. This question has prompted numerous investigations analyzing arm movements in both humans and monkeys. Many theories assume that among all possible movements the one actually performed satisfies an optimality criterion. In the framework of optimal control theory, a first approach is to choose a cost function and test whether the proposed model fits with experimental data. A second approach (generally considered as the more difficult) is to infer the cost function from behavioral data. The cost proposed here includes a term called the absolute work of forces, reflecti…
Next-generation cophylogeny: unravelling eco-evolutionary processes
2021
A fundamental question in evolutionary biology is how microevolutionary processes translate into species diversification. Cophylogeny provides an appropriate framework to address this for symbiotic associations, but historically has been primarily limited to unveiling patterns. We argue that it is essential to integrate advances from ecology and evolutionary biology into cophylogeny, to gain greater mechanistic insights and transform cophylogeny into a platform to advance understanding of interspecific interactions and diversification more widely. We discuss key directions, such as incorporating trait reconstruction and considering multiple scales of network organization, and highlight rece…
The phylogeny of the European high mountain genus Adenostyles (Asteraceae-Senecioneae) reveals that edaphic shifts coincide with dispersal events.
2013
UNLABELLED PREMISE OF THE STUDY Heterogeneity of edaphic conditions plays a large role in driving the diversification of many plant groups. In the Alps and other European high mountains, many closely related calcicole and calcifuge plant taxa exist. To better understand patterns and processes of edaphic differentiation, the phylogeny of the edaphically variable genus Adenostyles was studied. The genus contains three species, of which A. alpina has five subspecies. Each species and subspecies is largely confined to either calcareous or noncalcareous substrates. • METHODS We analyzed the phylogeny of Adenostyles using DNA sequences of nrITS, nrETS, nuclear chalcone synthase, and three plastid…
New records and observations to the Characean flora (Charales, Charophyceae) of Sicily (Italy)
2019
New records to the Characean flora of Sicily are presented. Five species (Chara baltica, C. conimbrigensis, C. oedophylla, Nitella gracilis, Tolypella salina) are new to Sicily, two of them being also new to Italy (Chara conimbrigensis, C. oedophylla). Two species are confirmed for Sicily (Chara aspera, Nitella opaca), three (Chara braunii, C. canescens, Nitella capillaris) are rare taxa. The Characean flora of Sicily, updated with these records, currently includes 25 species, distributed in four genera: Chara (13 species), Nitella (eight species), Tolypella (three species) and Lamprothamnium (one species).
Taxonomic investigations on Psoralea palaestina (Fabaceae), a critical species of Mediterranean flora
2016
Psoralea palaestina is a critical and unappreciated species described from Palestinian territories, and currently treated as synonym of P. bituminosa, nowadays known as Bituminaria bituminosa. Nomenclatural investigations allowed to ascertain that it was validly described for the first time by Bassi (1768) and not by Gouan (1773), as previously thought. Extensive taxonomic investigations revealed that this very peculiar legume is morphologically well differentiated from the other allied known species. Therefore, it has to be properly treated at specific level and transferred to the genus Bituminaria, thus proposing a new combination: Bituminaria palaestina. Based on literature, herbarium an…
Lectotypification of the Linnaean name Dianthus virgineus (Caryophyllaceae) and its taxonomic consequences
2021
A lectotype is designated for the name Dianthus virgineus. The relationships between D. virgineus, D. caryophyllus var. caryophyllus, and D. caryophyllus var. inodorus are analyzed. Dianthus virgineus is the oldest available name that applies to a species complex that is often referred to as D. sylvestris or a broad circumscription of the cultivated ornamental D. caryophyllus. The taxonomic consequences are discussed, and the need for further studies is highlighted.
Influence of female moulting status on pairing decisions and size‐assortative mating in amphipods
2012
8 pages; International audience; Precopulatory mate guarding is a common strategy, which has evolved in species where the female receptivity (and thus egg fertilization) is predictable, but also limited to a short period. Although males are larger than females in many amphipods, the largest males pair with the largest females, leading to a positive sizeassortative pairing. Size-assortative pairing has received much attention but how moulting physiology could affect pairing decisions has rarely been studied. Here, we tested the hypothesis that the size-assortative pairing in the freshwater amphipod Gammarus pulex is closely related to the female moult cycle. We characterized moulting status …