Accueil > Communication > Newsletter scientifique > Publications scientifiques

Publications scientifiques RSS des Publications scientifiques

Page(s) : < | 1 | ... | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | ... | 216 |

24 novembre 2017

Rapid hybrid speciation in Darwin’s finches [Science]

Subjects : genetics, evolution

Homoploid hybrid speciation in animals has been inferred frequently from patterns of variation, but few examples have withstood critical scrutiny. Here we report a directly documented example from its origin to reproductive isolation. An immigrant Darwin’s finch to Daphne Major in the Galápagos archipelago initiated a new genetic lineage by breeding with a resident finch (Geospiza fortis). Genome sequencing of the immigrant identified it as a G. conirostris male that originated on Española >100km from Daphne. From the second generation onwards the lineage bred endogamously, and despite intense inbreeding, was ecologically successful and showed transgressive segregation of bill morphology. This example shows that reproductive isolation, which typically develops over hundreds of generations, can be established in only three.

Lire la suite

24 novembre 2017

Networks of global bird invasion altered by regional trade ban [Science Advances]

Wildlife trade is a major pathway for introduction of invasive species worldwide. However, how exactly wildlife trade influences invasion risk, beyond the transportation of individuals to novel areas, remains unknown. We analyze the global trade network of wild-caught birds from 1995 to 2011 as reported by CITES (Convention on International Trade in Endangered Species of Wild Fauna and Flora). We found that before the European Union ban on imports of wild-caught birds, declared in 2005, invasion risk was closely associated with numbers of imported birds, diversity of import sources, and degree of network centrality of importer countries. After the ban, fluxes of global bird trade declined sharply. However, new trade routes emerged, primarily toward the Nearctic, Afrotropical, and Indo-Malay regions. Although regional bans can curtail invasion risk globally, to be fully effective and prevent rerouting of trade flows, bans should be global.

Lire la suite

24 novembre 2017

Temperature-dependent body size effects determine population responses to climate warming [Ecology Letters]

Keywords : allometric scaling, climate change, communities, consumer-resource dynamics, dynamic modelling, food webs, intraspecific competition, metabolic rate, predator–prey interactions, size structure

Current understanding of animal population responses to rising temperatures is based on the assumption that biological rates such as metabolism, which governs fundamental ecological processes, scale independently with body size and temperature, despite empirical evidence for interactive effects. Here, we investigate the consequences of interactive temperature- and size scaling of vital rates for the dynamics of populations experiencing warming using a stage-structured consumer-resource model. We show that interactive scaling alters population and stage-specific responses to rising temperatures, such that warming can induce shifts in population regulation and stage-structure, influence community structure and govern population responses to mortality. Analysing experimental data for 20 fish species,(...)

Lire la suite

24 novembre 2017

Lack of genetic population structure of slimy sculpin in a large, fragmented lake [Ecology of Freshwater Fish]

Keywords : barriers, gene flow, genetics, habitat fragmentation, microsatellites

Most of what is known about sculpin population structure comes from research in streams ; however, slimy sculpins are also a common benthic species in deep lakes. In streams, sculpins are considered to be a relatively inactive species, moving only small distances, and characteristically have high levels of genetic structure. We examined population genetic structure of slimy sculpin (Cottus cognatus) across multiple barriers and over distances up to 227 km in Lake Champlain (USA, Canada) and Lake Ontario (USA, Canada) to determine whether lake populations of sculpin are also highly structured.(...)

Lire la suite

23 novembre 2017

The architecture of mutualistic networks as an evolutionary spandrel [Nature Ecology & Evolution]

Keywords : ecological networks, theoretical ecology

Mutualistic networks have been shown to involve complex patterns of interactions among animal and plant species, including a widespread presence of nestedness. The nested structure of these webs seems to be positively correlated with higher diversity and resilience. Moreover, these webs exhibit marked measurable structural patterns, including broad distributions of connectivity, strongly asymmetrical interactions and hierarchical organization. Hierarchical organization is an especially interesting property, since it is positively correlated with biodiversity and network resilience, thus suggesting potential selection processes favouring the observed web organization. However, here we show that all these structural quantitative patterns—and nestedness in particular—can be properly explained by means of a very simple dynamical model of speciation and divergence with no selection-driven coevolution of traits. The agreement between observed and modelled networks suggests that the patterns displayed by real mutualistic webs might actually represent evolutionary spandrels.(...)

Lire la suite

Page(s) : < | 1 | ... | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | ... | 216 |