Aim Although sharing many similarities in their vegetation types, South America and Africa harbour very dissimilar recent mammal faunas, not only taxonomically but also in terms of several faunistic patterns. However late Pleistocene and mid-Holocene faunas, albeit taxonomically distinct, presented many convergent attributes. Here we propose that the effects of the Holocene climatic change on vegetation physiognomy has played a crucial role in shaping the extant mammalian faunistic patterns.Location South America and Africa from the late Pleistocene to the present.Methods Data presented here have been compiled from many distinct sources, including palaeontological and neontological mammalian studies, palaeoclimatology, palynology, and publications on vegetation ecology. Data on Pleistocene, Holocene and extant mammal faunas of South America and Africa allowed us to establish a number of similar and dissimilar faunistic patterns between the two continents across time. We then considered what changes in vegetation physiognomy would have occurred under the late Pleistocene last glacial maximum (LGM) and the Holocene climatic optimum (HCO) climatic regimes. We have ordained these proposed vegetation changes along rough physiognomic seral stages according to assumptions based on current botanical research. Finally, we have associated our hypothesized vegetation changes in South America and Africa with mammalian faunistic patterns, establishing a putative causal relationship between them. ResultsThe extant mammal faunas of South America and Africa differ widely in taxonomical composition; the number of medium and large species they possess; behavioural and ecological characteristics related to herbivore herding, migration and predation; and biogeographical patterns. All such distinctions are mostly related to the open formation faunas, and have been completely established around the mid-Holocene. Considering that the mid-Holocene was a time of greater humidity than the late Pleistocene, vegetation cover in South America and Africa would have been dominated by forest or closed vegetation landscapes, at least for most of their lower altitude tropical regions. We attribute the loss of larger-sized mammal lineages in South America to the decrease of open vegetation area, and their survival in Africa to the existence of vast savannas in formerly steppic or desertic areas in subtropical Africa, north and south of the equator. Alternative explanations, mostly dealing with the disappearance of South American megamammals, are then reviewed and criticized. Main conclusionsThe reduction of open formation areas during the HCO in South America and Africa explains most of the present distinct faunistic patterns between the two continents. While South America would have lost most of its open formations within the 30°latitudinal belt, Africa would have kept large areas
Patterns of interspecific differentiation in saki monkeys (Pithecia) are quantitatively described and possible evolutionary processes producing them are examined. The comparison of species correlation matrices to expected patterns of morphological integration reveal significant and similar patterns of development‐based cranial integration among species. Aspects of the facial region are more heavily influenced by general size variation than features of the neural region. The comparison of pooled within‐ and between‐groups V/CV matrices suggests that genetic drift might be a sufficient explanation for saki cranial evolution. Differential natural selection gradients are also reconstructed because selection may also have caused population differentiation through evolutionary time. These gradients illustrate the inherent multivariate nature of selection, being a consequence of the interaction between existing morphological integration (correlation) among traits and the action of natural selection. Yet, our attempt to interpret selection gradients in terms of their functional significance did not result in any clear association between selection and function. Perhaps this is also an indication that morphological evolution in sakis was mostly neutral.
São Paulo harbors 231 mammal species until now. This is an estimate of its real diversity since many regions of the State continue poorly surveyed, and also reflects the lack of taxonomic work for certain mammal taxa. Nevertheless, our knowledge of the São Paulo mammals has increased in 20% in the last 12 years, especially in relation to bats and rodents. These new data are based in mammal inventories and also in the analysis of specimens housed in scientific collections associated with taxonomic revisions. We also know better about the mammal distribution in the distinct vegetation units present in the State, permitting us to divide the mammals in three distinct components: the most important one is the generalists, represented by species occurring in every landscape in the State, while the second one concentrates species inhabiting the open formations, and the third component the species associated with the forest formations. Besides, the number of studies dealing with the effect of fragmentation and the permeability of mammals in altered areas also has increased. Occurrence, abundance and vulnerability data were essential to raise strategies in order to choose priority areas and to indicate priority actions to conserve the mammals of the State, as well as to classify the species in the different proposed threaten categories, culminating in the List of the Threaten Species of the São Paulo State. However, there are many points yet poorly developed or poorly known, such as the limited number of zoological samples, and the lack of information about the ecology and natural history of many species, respectively. It's extremely important that we increase our samples in the scientific collections, especially in areas of Dense Ombrofilous Forests, in the Cerrado fragments, as well as in central and western areas of the State that continue poorly surveyed. The objective is to produce more taxonomic work in several mammalian groups, and also studies focusing in the phylogeography and in the population genetics in order to effectively diagnose the mammal richness of the State, as well as the evolutionary processes responsible for this diversification. Additionally, ecological data accompanying this information is needed in order to evaluate the conservation status of the São Paulo mammals to decide about the better strategies to manage and conserve these mammals.
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