DESBIEZ, A.L.J.; SANTOS, S.A.; KEUROGHLIAN, A.; BODMER, R.E. 2009. Niche partitioning among white-lipped peccaries (Tayassu pecari), collared peccaries (Pecari tajacu), and feral pigs (Sus scrofa). Journal of Mammlogy 90(1):119-128.
Abstract. The introduction of a species into an ecosystem with species already occupying a similar trophic level is predicted to lead to a high degree of niche overlap. The feral pig (Sus scrofa), one of the world’s worst invasive species, was introduced to the Pantanal about 200 years ago and is thought to compete with the native whitelipped peccary (Tayassu pecari) and collared peccary (Pecari tajacu). Resource partitioning between the 3 species was examined, including analysis of fruit items and plants in fecal samples as well as encounter rates in different habitats, to help generate hypotheses about competitive interactions among the species. Overlaps in food resources and habitat use between feral pigs and peccaries were found to be lower than expected. In fact, niche overlap as highest between the native species. Results indicate that currently, feral pigs are not a direct threat to the native peccaries in the study area. Differences in morphology and behavior indicate possible mechanisms of niche partitioning between the species. Feral pigs may, nevertheless, impact the wildlife community in other ways as predators of eggs, by destruction of vegetation through rooting, or by functioning as disease reservoirs. Cattle-ranching activities may favor feral pigs and the current anthropogenic changes in the landscape could lead to changes in competitive dynamics between feral pigs and native species.
Mostrando postagens com marcador Artiodactyla. Mostrar todas as postagens
Mostrando postagens com marcador Artiodactyla. Mostrar todas as postagens
sábado, 10 de janeiro de 2015
sábado, 15 de novembro de 2014
The phylogeny of Cetartiodactyla: the importance of dense taxon sampling, missing data, and the remarkable promise of cytochrome b to provide realiable species-level phylogenies
AGNARSSON, I.; MAY-COLLADO, L.J. 2008. The phylogeny of Cetartiodactyla: the importance of dense taxon sampling, missing data, and the remarkable promise of cytochrome b to provide realiable species-level phylogenies. Molecular Phylogenetics and Evolution 48:964-985.
Abstract. We perform Bayesian phylogenetic analyses on cytochrome b sequences from 264 of the 290 extant cetartiodactyl mammals (whales plus even-toed ungulates) and two recently extinct species, the "Mouse Goad" and the "Irish Elk". Previous primary analyses have included only a small portion of the species diversity within Cetartiodactyla, while a complete supertree analysis lacks resolution and branch lenghts limiting its utility for comparative studies. The benefits of using a single-gene approach include rapid phylogenetic estimates for a large number of species. However, single-gene phylogenies often differ dramatically from studies involving multiple datasets suggesting that they often are unrealiable. However, based on recovery of banchmark clades - clades supported in prior studies based on multiple independent datasets - and recovery of undisputed traditional taxonomic groups, Cytb performs extraordinarily well in resolving cetartiodactyl phylogeny when taxon sampling is dense. Missing data, however, (taxa with partial sequences) can compromise phylogenetic accuracy, suggesting a tradeoff between the benefits of adding taxa and introducing question marks. In the full data, a fez species with a short sequences appear misplaced, however, sequence lenght alone seems a poor predictor of this phenomenon as other taxa with equally short sequences were not conspicuously misplaced. Although we recommend awaiting a better supported phylogenetic hypotheses provided here represent the currently best available tool for comparative species-level studies within this group. Cytb has been sequenced for a large percentage of mammals and appears to be a reliable phylogenetic marker as long as taxon sampling is dense. Therefore, an opportunity exists now to reconstruct detailed phylogenies of most of the major mammalian clades to rapidly provide much needed tools for species-level comparative studies.
Abstract. We perform Bayesian phylogenetic analyses on cytochrome b sequences from 264 of the 290 extant cetartiodactyl mammals (whales plus even-toed ungulates) and two recently extinct species, the "Mouse Goad" and the "Irish Elk". Previous primary analyses have included only a small portion of the species diversity within Cetartiodactyla, while a complete supertree analysis lacks resolution and branch lenghts limiting its utility for comparative studies. The benefits of using a single-gene approach include rapid phylogenetic estimates for a large number of species. However, single-gene phylogenies often differ dramatically from studies involving multiple datasets suggesting that they often are unrealiable. However, based on recovery of banchmark clades - clades supported in prior studies based on multiple independent datasets - and recovery of undisputed traditional taxonomic groups, Cytb performs extraordinarily well in resolving cetartiodactyl phylogeny when taxon sampling is dense. Missing data, however, (taxa with partial sequences) can compromise phylogenetic accuracy, suggesting a tradeoff between the benefits of adding taxa and introducing question marks. In the full data, a fez species with a short sequences appear misplaced, however, sequence lenght alone seems a poor predictor of this phenomenon as other taxa with equally short sequences were not conspicuously misplaced. Although we recommend awaiting a better supported phylogenetic hypotheses provided here represent the currently best available tool for comparative species-level studies within this group. Cytb has been sequenced for a large percentage of mammals and appears to be a reliable phylogenetic marker as long as taxon sampling is dense. Therefore, an opportunity exists now to reconstruct detailed phylogenies of most of the major mammalian clades to rapidly provide much needed tools for species-level comparative studies.
sábado, 15 de fevereiro de 2014
Variabilidade genética en géneros de ciervos neotropicales (Mammalia: Cervidae) según loci microsatelitales
RUIZ-GARCÍA, M.; MARTINEZ-AGÜERO, M.; ÁLVAREZ, D.; GOODMAN, S. 2009. Variabilidade genética en géneros de ciervos neotropicales (Mammalia: Cervidae) según loci microsatelitales. Revista de Biología Tropical 57(3):879-904.
Abstract. Genetic variability in Neotropical deer genera (Mammalia: Cervidae) according to DNA
microsatellite loci. Species conservation programs are highly based on analyses of population genetics. We compared eight Neotropical Cervidae (Mazama americana, M. gouzaoubira, M. rufina, Odocoileus virginianus, Hippocamelus antisensis, Pudu mephistopholes, Ozotoceros bezoarticus and Blastoceros dichotomus) and some European and Asian Cervidae (Cervus elaphus, C. nippon, Capreolus capreolus, C. pygargus and Dama dama). The European species C. elaphus was our standard for a high degree of genetic variability: we used a Scottish population originated in the mix of diverse Western European subspecies. On the contrary, Cervus nippon (a population from Scotland with a founder effect) was our standard for a depauperated population. The M. americana, M. gouzaoubira and O. virginianus samples had high diversity values close to our C. elaphus population (H= 0.64, 0.70 and 0.61, respectively), while M. rufina was very low, close to C. nippon. Several sample sets of Mazama and Odocoileus yielded a homozygote excess, probably due to the Wahlund (subdivison) effect. There was no evidence of recent bottleneck events.
Abstract. Genetic variability in Neotropical deer genera (Mammalia: Cervidae) according to DNA
microsatellite loci. Species conservation programs are highly based on analyses of population genetics. We compared eight Neotropical Cervidae (Mazama americana, M. gouzaoubira, M. rufina, Odocoileus virginianus, Hippocamelus antisensis, Pudu mephistopholes, Ozotoceros bezoarticus and Blastoceros dichotomus) and some European and Asian Cervidae (Cervus elaphus, C. nippon, Capreolus capreolus, C. pygargus and Dama dama). The European species C. elaphus was our standard for a high degree of genetic variability: we used a Scottish population originated in the mix of diverse Western European subspecies. On the contrary, Cervus nippon (a population from Scotland with a founder effect) was our standard for a depauperated population. The M. americana, M. gouzaoubira and O. virginianus samples had high diversity values close to our C. elaphus population (H= 0.64, 0.70 and 0.61, respectively), while M. rufina was very low, close to C. nippon. Several sample sets of Mazama and Odocoileus yielded a homozygote excess, probably due to the Wahlund (subdivison) effect. There was no evidence of recent bottleneck events.
sábado, 20 de agosto de 2011
A complete phylogeny of the whales, dolphins and even-toed hoofed mammals (Cetartiodactyla)
PRICE, S.A.; BININDA-EMONDS, O.R.P.; GITTLEMAN, J.L. 2005. A complete phylogeny of the whales, dolphins and even-toed hoofed mammals (Cetartiodactyla). Biology Review 80:445-473.
Abstract. Despite the biological and economic importance of the Cetartiodactyla, the phylogeny of this clade remains controversial. Using the supertree approach of matrix representation with parsimony, we present the first phylogeny to include all 290 extant species of the Cetacea (whales and dolphins) and Artiodactyla (even-toed hoofed mammals). At the family-level, the supertree is fully resolved. For example, the relationships among the Ruminantia appear as (((Cervidae, Moschidae) Bovidae) (Giraffidae, Antilocapridae) Tragulidae). However, due to either lack of phylogenetic study or contradictory information, polytomies occur within the clades Sus, Muntiacus, Cervus, Delphinidae, Ziphiidae and Bovidae. Complete species-level phylogenies are necessary for both illustrating and analysing biological, geographical and ecological patterns in an evolutionary framework. The present species-level tree of the Cetartiodactyla provides the first opportunity to examine comparative hypotheses across entirely aquatic and terrestrial species within a single mammalian order.
Abstract. Despite the biological and economic importance of the Cetartiodactyla, the phylogeny of this clade remains controversial. Using the supertree approach of matrix representation with parsimony, we present the first phylogeny to include all 290 extant species of the Cetacea (whales and dolphins) and Artiodactyla (even-toed hoofed mammals). At the family-level, the supertree is fully resolved. For example, the relationships among the Ruminantia appear as (((Cervidae, Moschidae) Bovidae) (Giraffidae, Antilocapridae) Tragulidae). However, due to either lack of phylogenetic study or contradictory information, polytomies occur within the clades Sus, Muntiacus, Cervus, Delphinidae, Ziphiidae and Bovidae. Complete species-level phylogenies are necessary for both illustrating and analysing biological, geographical and ecological patterns in an evolutionary framework. The present species-level tree of the Cetartiodactyla provides the first opportunity to examine comparative hypotheses across entirely aquatic and terrestrial species within a single mammalian order.
Assinar:
Postagens (Atom)