Can sexual selection theory inform genetic management of captive populations? A review

International audienceCaptive breeding for conservation purposes presents a serious practical challenge because several conflicting genetic processes (i.e., inbreeding depression, random genetic drift and genetic adaptation to captivity) need to be managed in concert to maximize captive population persistence and reintroduction success probability. Because current genetic management is often only partly successful in achieving these goals, it has been suggested that management insights may be found in sexual selection theory (in particular, female mate choice). We review the theoretical and empirical literature and consider how female mate choice might influence captive breeding in the context of current genetic guidelines for different sexual selection theories (i.e., direct benefits, good genes, compatible genes, sexy sons). We show that while mate choice shows promise as a tool in captive breeding under certain conditions, for most species, there is currently too little theoretical and empirical evidence to provide any clear guidelines that would guarantee positive fitness outcomes and avoid conflicts with other genetic goals. The application of female mate choice to captive breeding is in its infancy and requires a goal-oriented framework based on the needs of captive species management, so researchers can make honest assessments of the costs and benefits of such an approach, using simulations, model species and captive animal data

Does recognized genetic management in supportive breeding prevent genetic changes in life-history traits?

International audienceSupportive 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 as evidenced by an increase in breeding values for all traits. These changes resulted from selection acting on gamete production and to a lesser extent on courtship display. Selection decreased over years for female gametes, emphasizing the effort of managers to increase the contribution of poor breeders to offspring recruited in the captive breeding. Our results shed light on very fast genetic changes in an exemplary captive programme that follows worldwide used recommendations and emphasizes the need of more empirical evidence of the effects of genetic guidelines on the prevention of genetic changes in supportive breeding

Quantitative Genetics of the Aging of Reproductive Traits in the Houbara Bustard

International audienceDo all traits within an organism age for the same reason? Evolutionary theories of aging share a common assumption: the strength of natural selection declines with age. A corollary is that additive genetic variance should increase with age. However, not all senescent traits display such increases suggesting that other mechanisms may be at play. Using longitudinal data collected from more than 5400 houbara bustards (Chlamydotis undulata) with an exhaustive recorded pedigree, we investigated the genetics of aging in one female reproductive trait (egg production) and three male reproductive traits (courtship display rate, ejaculate size and sperm viability), that display senescence at the phenotypic level. Animal models revealed an increase in additive genetic variance with age for courtship display rate and egg production but an unexpected absence of increased additive genetic variance for ejaculate size and no additive genetic variance for sperm viability. Our results suggest that the mechanisms behind the senescence of some traits are linked with a change in genetic expression, whereas for some other traits, aging may result from the constraints associated with physiological wear and tear on the organism throughout the life of the individual

Adaptive responses of animals to climate change are most likely insufficient

Biological responses to climate change have been widely documented across taxa and regions, but it remains unclear whether species are maintaining a good match between phenotype and environment, i.e. whether observed trait changes are adaptive. Here we reviewed 10,090 abstracts and extracted data from 71 studies reported in 58 relevant publications, to assess quantitatively whether phenotypic trait changes associated with climate change are adaptive in animals. A meta-analysis focussing on birds, the taxon best represented in our dataset, suggests that global warming has not systematically affected morphological traits, but has advanced phenological traits. We demonstrate that these advances are adaptive for some species, but imperfect as evidenced by the observed consistent selection for earlier timing. Application of a theoretical model indicates that the evolutionary load imposed by incomplete adaptive responses to ongoing climate change may already be threatening the persistence of species

Archiving primary data: solutions for long-term studies

The recent trend for journals to require open access to primary data included in publications has been embraced by many biologists, but has caused apprehension amongst researchers engaged in long-term ecological and evolutionary studies. A worldwide survey of 73 principal investigators (Pls) with long-term studies revealed positive attitudes towards sharing data with the agreement or involvement of the PI, and 93% of PIs have historically shared data. Only 8% were in favor of uncontrolled, open access to primary data while 63% expressed serious concern. We present here their viewpoint on an issue that can have non-trivial scientific consequences. We discuss potential costs of public data archiving and provide possible solutions to meet the needs of journals and researchers

Adaptive responses of animals to climate change are most likely insufficient

Biological responses to climate change have been widely documented across taxa and regions, but it remains unclear whether species are maintaining a good match between phenotype and environment, i.e. whether observed trait changes are adaptive. Here we reviewed 10,090 abstracts and extracted data from 71 studies reported in 58 relevant publications, to assess quantitatively whether phenotypic trait changes associated with climate change are adaptive in animals. A meta-analysis focussing on birds, the taxon best represented in our dataset, suggests that global warming has not systematically affected morphological traits, but has advanced phenological traits. We demonstrate that these advances are adaptive for some species, but imperfect as evidenced by the observed consistent selection for earlier timing. Application of a theoretical model indicates that the evolutionary load imposed by incomplete adaptive responses to ongoing climate change may already be threatening the persistence of species. © 2019, The Author(s)

Evolutionary consequences of climate change in birds

International audienc

Sensibilité des défenses induites à différentes modalités de prédation (cas des têtards d'anoures)

La variabilité de l'environnement (spatiale ou temporelle) nécessite que les organismes développent des adaptations telles que sélection de l'habitat, polymorphisme génétique, hétéroblastie ou encore plasticité phénotypique. La gamme de la variabilité nécessite de développer différents phénotypes et la fréquence de variabilité détermine quelle est la réponse la plus adaptée. Lorsque l'échelle de variation de l'environnement est inférieure à la durée de vie de l'organisme et supérieure à ses capacités de dispersion, une réponse plastique sera avantagée. La théorie prévoit que plus l'environnement est variable (en termes de gamme de variation ou de fréquence de variation), plus la réponse plastique devrait être importante, soit en termes d'intensité de réponse soit en termes de nombre de traits impliqués. La variabilité des interactions biotiques constitue un cadre idéal pour tester cette prédiction. Le cas de réponses plastiques à la prédation a été particulièrement bien étudié, sous le terme de défenses induites. Le but de cette thèse a été d'étudier l'impact de la variabilité de la présence de prédateurs (en termes de type de prédateurs ou de densité de prédateurs) sur les défenses induites des têtards d'anoures (Rana dalmatina, R. ridibunda et H. arborea). Je me suis principalement intéressée à un prédateur actif (épinoche, Gasterosteus aculeatus) que j'ai également comparé aux prédateurs de type "à l'affût" (Aeshne, Aeshna sp.) .Les principaux résultats sont: (1)La fréquence de variabilité de l'environnement joue sur le nombre de traits impliqués dans la réponse. (2)La gamme de variation de l'environnement joue sur le degré de plasticité par le biais (1) de la densité de prédateurs qui résulte en un investissement plus important dans les défenses et (2) du type de prédateur qui sélectionne des défenses spécifiques à un mode d'attaque du fait de mécanismes de réponses différents. En réponse à un prédateur actif, les têtards développent une musculature plus importante, qui permet une vitesse de fuite plus élevée. En réponse à un prédateur a l'affût, les têtards développent une nageoire plus haute, ce qui est supposé provoquer un effet de leurre.(3)Lorsque les deux types de prédateurs sont simultanément présents, les têtards répondent hiérarchiquement en développant la réponse spécifique adaptée au prédateur le plus dangereux (ici l'Aeshne). (4)Les réponses induites par les prédateurs actifs présentent un bénéfice. En présence directe de prédateurs, la survie des têtards ayant une musculature plus importante est plus élevée. (5)Les coûts des défenses s'expriment par une diminution du taux de croissance. Cette étude contribue à démontrer la sensibilité des réponse plastiques à la fréquence et la gamme de variations de l'environnement et suggère que des facteurs autre que la prédation (e. g. structure de l'habitat, quantité de nourriture, perturbation anthropiques) peuvent jouer sur le développement des défenses induites.LYON1-BU.Sciences (692662101) / SudocSudocFranceF