Search results for "game"
showing 10 items of 1663 documents
The “unguarded-X” and the genetic architecture of lifespan: Inbreeding results in a potentially maladaptive sex-specific reduction of female lifespan…
2018
Sex differences in ageing and lifespan are ubiquitous in nature. The "unguarded-X" hypothesis (UXh) suggests they may be partly due to the expression of recessive mutations in the hemizygous sex chromosomes of the heterogametic sex, which could help explain sex-specific ageing in a broad array of taxa. A prediction central to the UX hypothesis is that inbreeding will decrease the lifespan of the homogametic sex more than the heterogametic sex, because only in the former does inbreeding increase the expression of recessive deleterious mutations. In this study, we test this prediction by examining the effects of inbreeding on the lifespan and fitness of male and female Drosophila melanogaster…
Intensive Management and Natural Genetic Variation in Red Deer (Cervus elaphus)
2017
The current magnitude of big-game hunting has outpaced the natural growth of populations, making artificial breeding necessary to rapidly boost hunted populations. In this study, we evaluated if the rapid increase of red deer (Cervus elaphus) abundance, caused by the growing popularity of big-game hunting, has impacted the natural genetic diversity of the species. We compared several genetic diversity metrics between 37 fenced populations subject to intensive management and 21 wild free-ranging populations. We also included a historically protected population from a national park as a baseline for comparisons. Contrary to expectations, our results showed no significant differences in geneti…
Debating Sexual Selection and Mating Strategies
2006
Published at full length with the title 'Reproductive behaviour: sexual selection remains the best explanation' in Science E-letters, 6 April 2006
A Tale of Big Game and Small Bugs
1999
Animal populations undergo repetitive cycles of rising and falling numbers. In a Perspective, [Ranta and colleagues][1] discuss the value of time-series analyses for examining the changing dynamics of animal populations. A large time series gathered by the Hudson Bay Company based on the fur trade has provided invaluable data on the rise and fall of the Canadian lynx population from 1821 to the present. Analysis of this time series reveals that climate as well as factors influencing birth and death rates are important in regulating the lynx population ([ Stenseth et al .][2]). In a separate study, mathematical modeling combined with fieldwork revealed the importance of predators in determin…
Adaptive strategies of territory formation
2003
How do territorial animals gain ownership of an area? Early modelling has considered the evolution of fighting when the winner can claim the right to the resource. Recently, alternative hypotheses have been offered where repeated interactions lead to division of space through 'nagging' instead of one decisive fight. However, these models assume that animals avoid areas in which they have taken part in aggressive interactions, but do not consider whether avoidance itself is adaptive. We aim to bridge this gap between mechanistic and adaptive explanations, by presenting a game-theory model where individuals choose whether to return to an area after a fight with a specific outcome (win, loss, …
Cytological and molecular characterization of three gametoclones of Citrus clementina
2013
Abstract Background Three gametoclonal plants of Citrus clementina Hort. ex Tan., cv. Nules, designated ESP, FRA, and ITA (derived from three labs in Spain, France, and Italy, respectively), were selected for cytological and molecular characterization in order to elucidate genomic rearrangements provoked by haploidization. The study included comparisons of their ploidy, homozygosity, genome integrity, and gene dosage, using chromosome counting, flow cytometry, SSR marker genotyping, and array-Comparative Genomic Hybridization (array-CGH). Results Chromosome counting and flow cytometry revealed that ESP and FRA were haploid, but ITA was tri-haploid. Homozygous patterns, represented by a sing…
Does recognized genetic management in supportive breeding prevent genetic changes in life-history traits?
2014
International audience; Supportive breeding is one of the last resort conservation strategies to avoid species extinction. Management of captive populations is challenging because several harmful genetic processes need to be avoided. Several recommendations have been proposed to limit these deleterious effects, but empirical assessments of these strategies remain scarce. We investigated the outcome of a genetic management in a supportive breeding for the Houbara Bustard. At the phenotypic level, we found an increase over generations in the mean values of gamete production, body mass and courtship display rate. Using an animal model, we found that phenotypic changes reflected genetic changes…
Cross inhibition improves activity selection when switching incurs time costs
2015
Abstract We consider a behavioural model of an animal choosing between two activities, based on positive feedback, and examine the effect of introducing cross inhibition between the motivations for the two activities. While cross-inhibition has previously been included in models of decision making, the question of what benefit it may provide to an animal’s activity selection behaviour has not previously been studied. In neuroscience and in collective behaviour cross-inhibition, and other equivalent means of coupling evidence-accumulating pathways, have been shown to approximate statistically-optimal decision-making and to adaptively break deadlock, thereby improving decision performance. Sw…
Factors affecting population dynamics of Eurasian woodcocks wintering in France: assessing the efficiency of a hunting-free reserve
2005
International audience; The Eurasian woodcock Scolopax rusticola is a migratory bird of major importance for hunting, which is susceptible to habitat loss and the stochastic effects of severe winter weather. Conservation issues mostly concerned regulation of hunting, but the efficiency of hunting-free reserves has never been investigated. We studied causes of mortality and survival probabilities of 98 radio-tagged woodcocks in a reserve with no hunting and in an adjoining hunting area in Brittany (France). Predation, mostly by mammalian predators on fields at night, was similar among adults and yearlings, while hunting mortality was more important in yearlings. Overall winter survival proba…
Precision, Applicability, and Economic Implications: A Comparison of Alternative Biodiversity Offset Indexes
2021
AbstractThe rates of ecosystem degradation and biodiversity loss are alarming and current conservation efforts are not sufficient to stop them. The need for new tools is urgent. One approach is biodiversity offsetting: a developer causing habitat degradation provides an improvement in biodiversity so that the lost ecological value is compensated for. Accurate and ecologically meaningful measurement of losses and estimation of gains are essential in reaching the no net loss goal or any other desired outcome of biodiversity offsetting. The chosen calculation method strongly influences biodiversity outcomes. We compare a multiplicative method, which is based on a habitat condition index develo…