72 research outputs found
The genome of the endangered dryas monkey provides new Insights into the evolutionary history of the vervets
Genomic data can be a powerful tool for inferring ecology, behaviour and conservation needs of highly elusive species, particularly when other sources of information are hard to come by. Here we focus on the dryas monkey, an endangered primate endemic to the Congo Basin with cryptic behaviour and possibly less than 250 remaining individuals. Using whole genome data we show that the dryas monkey represents a sister lineage to the vervet monkeys and has diverged from them at least 1 million years ago with additional bi-directional gene flow 590,000 – 360,000 years ago. After bonobo-chimpanzee admixture, this is the second reported case of gene flow that most likely involved crossing the Congo River, a strong dispersal barrier. As the demographic history of bonobos and dryas monkey shows similar patterns of population increase during this time period, we hypothesise that the fluvial topology of the Congo River might have been more dynamic than previously recognised. As a result of dryas monkey - vervet admixture, genes involved in resistance to the simian immunodeficiency virus (SIV) have been exchanged, possibly indicating adaptive introgression. Despite the presence of several homozygous loss-of-function mutations in genes associated with reduced sperm mobility and immunity, we find high genetic diversity and low levels of inbreeding and genetic load in the studied dryas monkey individual. This suggests that the current population carries sufficient genetic variability for the long-term survival of this species. We thus provide an example of how genomic data can directly improve our understanding of elusive species
Lesula: A New Species of Cercopithecus Monkey Endemic to the Democratic Republic of Congo and Implications for Conservation of Congo’s Central Basin
In June 2007, a previously undescribed monkey known locally as “lesula” was found in the forests of the middle Lomami Basin in central Democratic Republic of Congo (DRC). We describe this new species as Cercopithecus lomamiensis sp. nov., and provide data on its distribution, morphology, genetics, ecology and behavior. C. lomamiensis is restricted to the lowland rain forests of central DRC between the middle Lomami and the upper Tshuapa Rivers. Morphological and molecular data confirm that C. lomamiensis is distinct from its nearest congener, C. hamlyni, from which it is separated geographically by both the Congo (Lualaba) and the Lomami Rivers. C. lomamiensis, like C. hamlyni, is semi-terrestrial with a diet containing terrestrial herbaceous vegetation. The discovery of C. lomamiensis highlights the biogeographic significance and importance for conservation of central Congo’s interfluvial TL2 region, defined from the upper Tshuapa River through the Lomami Basin to the Congo (Lualaba) River. The TL2 region has been found to contain a high diversity of anthropoid primates including three forms, in addition to C. lomamiensis, that are endemic to the area. We recommend the common name, lesula, for this new species, as it is the vernacular name used over most of its known range
Pan paniscus (errata version published in 2016)
Due to high levels of illegal hunting, and habitat destruction and degradation,Pan paniscusis estimated to have experienced a significant population reduction in the last 15–20 years and it is thought that this reduction will continue for the next 60 years. Currently, by far the greatest threat to the Bonobo's survival is poaching for the commercial bushmeat trade. It has been estimated that nine tons of bushmeat are extracted daily from a 50,000-km² conservation landscape within the Bonobo’s range. Not only is there is a massive demand for bushmeat stemming from the cities, but rebel factions and poorly-paid government soldiers add to that demand, at the same time facilitating the flow of guns and ammunition (Fruthet al. 2013). In some areas, local taboos against eating Bonobo meat still exist, but in others, these traditions are disintegrating due to changing cultural values and population movements. Stricter enforcement of wildlife laws and more effective management are urgently needed. Habitat loss through deforestation and fragmentation ranks second. Much of the forest loss in this region is caused by slash-and-burn subsistence agriculture, which is most intense where human densities are high or growing. Logging and mining do not yet occur on an industrial scale in the Bonobo’s range, but in future, industrial agriculture is very likely to become a serious threat. Minimising the conversion of intact forest to human-dominated land uses, will be critical for the future survival of Bonobos. Countrywide factors contributing to the decline include the mobility of growing human populations, opening markets, commercial exploitation of natural resources and road construction. As in the past, the survival of Bonobos will be determined by the levels of poaching and forest loss—threats that have been shown to accompany rapid growth in human populations and political instability (Nackoneyet al. 2014). Due to their slow life history and a generation time estimated to be 25 years, Bonobo populations cannot withstand high levels of offtake. The population decline over a three-generation (75 year) period from 2003 to 2078 is likely to exceed 50%, hence qualifying this taxon as Endangered under criterion A
Allometry and Ecology of the Bilaterian Gut Microbiome.
Classical ecology provides principles for construction and function of biological communities, but to what extent these apply to the animal-associated microbiota is just beginning to be assessed. Here, we investigated the influence of several well-known ecological principles on animal-associated microbiota by characterizing gut microbial specimens from bilaterally symmetrical animals (Bilateria) ranging from flies to whales. A rigorously vetted sample set containing 265 specimens from 64 species was assembled. Bacterial lineages were characterized by 16S rRNA gene sequencing. Previously published samples were also compared, allowing analysis of over 1,098 samples in total. A restricted number of bacterial phyla was found to account for the great majority of gut colonists. Gut microbial composition was associated with host phylogeny and diet. We identified numerous gut bacterial 16S rRNA gene sequences that diverged deeply from previously studied taxa, identifying opportunities to discover new bacterial types. The number of bacterial lineages per gut sample was positively associated with animal mass, paralleling known species-area relationships from island biogeography and implicating body size as a determinant of community stability and niche complexity. Samples from larger animals harbored greater numbers of anaerobic communities, specifying a mechanism for generating more-complex microbial environments. Predictions for species/abundance relationships from models of neutral colonization did not match the data set, pointing to alternative mechanisms such as selection of specific colonists by environmental niche. Taken together, the data suggest that niche complexity increases with gut size and that niche selection forces dominate gut community construction.IMPORTANCEThe intestinal microbiome of animals is essential for health, contributing to digestion of foods, proper immune development, inhibition of pathogen colonization, and catabolism of xenobiotic compounds. How these communities assemble and persist is just beginning to be investigated. Here we interrogated a set of gut samples from a wide range of animals to investigate the roles of selection and random processes in microbial community construction. We show that the numbers of bacterial species increased with the weight of host organisms, paralleling findings from studies of island biogeography. Communities in larger organisms tended to be more anaerobic, suggesting one mechanism for niche diversification. Nonselective processes enable specific predictions for community structure, but our samples did not match the predictions of the neutral model. Thus, these findings highlight the importance of niche selection in community construction and suggest mechanisms of niche diversification
Comparing tropical forest tree size distributions with the predictions of metabolic ecology and equilibrium models
Tropical forests vary substantially in the densities of trees of different sizes and thus in above-ground biomass and carbon stores. However, these tree size distributions show fundamental similarities suggestive of underlying general principles. The theory of metabolic ecology predicts that tree abundances will scale as the -2 power of diameter. Demographic equilibrium theory explains tree abundances in terms of the scaling of growth and mortality. We use demographic equilibrium theory to derive analytic predictions for tree size distributions corresponding to different growth and mortality functions. We test both sets of predictions using data from 14 large-scale tropical forest plots encompassing censuses of 473 ha and \u3e 2 million trees. The data are uniformly inconsistent with the predictions of metabolic ecology. In most forests, size distributions are much closer to the predictions of demographic equilibrium, and thus, intersite variation in size distributions is explained partly by intersite variation in growth and mortality. © 2006 Blackwell Publishing Ltd/CNRS
Testing metabolic ecology theory for allometric scaling of tree size, growth and mortality in tropical forests
The theory of metabolic ecology predicts specific relationships among tree stem diameter, biomass, height, growth and
mortality. As demographic rates are important to estimates of carbon fluxes in forests, this theory might offer important insights into
the global carbon budget, and deserves careful assessment. We assembled data from 10 old-growth tropical forests encompassing
censuses of 367 ha and > 1.7 million trees to test the theory's predictions. We also developed a set of alternative predictions
that retained some assumptions of metabolic ecology while also considering how availability of a key limiting resource, light, changes
with tree size. Our results show that there are no universal scaling relationships of growth or mortality with size among trees in tropical
forests. Observed patterns were consistent with our alternative model in the one site where we had the data necessary to evaluate it,
and were inconsistent with the predictions of metabolic ecology in all forests
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