Global dynamics of stationary solutions of the extended Fisher-Kolmogorov equation

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Patch-size and isolation effects in the Fisher-Kolmogorov equation

We examine the classical problem of the existence of a threshold size for a patch to allow for survival of a given population in the case where the patch is not completely isolated. The surrounding habitat matrix is characterized by a non-zero carrying capacity. We show that a critical patch size cannot be strictly defined in this case. We also obtain the saturation density in such a patch as a function of the size of the patch and the relative carrying capacity of the outer region. We argue that this relative carrying capacity is a measure of the isolation of the patch. Our results are then compared with conclusions drawn from observations of the population dynamics of understorey birds in fragments of the Amazonian forest and shown to qualitatively agree with them, offering an explanation for the importance of dispersal and isolation in these observations. Finally, we show that a generalized critical patch size can be introduced resorting to threshold densities for the observation of a given species.

Amphibia, Anura, Centrolenidae, Hyalinobatrachium carlesvilai Castroviejo-Fisher, Padial, Chaparro, Aguayo and de la Riva, 2009: First country record, Brazil

We present the first Brazilian record of the recently-described glassfrog Hyalinobatrachium carlesvilai Castroviejo-Fisher, Padial, Chaparro, Aguayo and de la Riva, 2009. This species, previously known in Peru and Bolivia, was collected at two localities at the municipality of Aripuanã, northern state of Mato Grosso, Brazil. © 2010 Check List and Authors.

Desenvolvimento de aplicativo para o método de discriminação de Fisher e seu uso na experimentação agronômica: Carlos Roberto Pereira Padovani. -

Pós-graduação em Agronomia (Energia na Agricultura) - FCA

Khoisan hunter-gatherers have been the largest population throughout most of modern-human demographic history

The Khoisan people from Southern Africa maintained ancient lifestyles as hunter-gatherers or pastoralists up to modern times, though little else is known about their early history. Here we infer early demographic histories of modern humans using whole-genome sequences of five Khoisan individuals and one Bantu speaker. Comparison with a 420 K SNP data set from worldwide individuals demonstrates that two of the Khoisan genomes from the Ju/'hoansi population contain exclusive Khoisan ancestry. Coalescent analysis shows that the Khoisan and their ancestors have been the largest populations since their split with the non-Khoisan population similar to 100-150 kyr ago. In contrast, the ancestors of the non-Khoisan groups, including Bantu-speakers and non-Africans, experienced population declines after the split and lost more than half of their genetic diversity. Paleoclimate records indicate that the precipitation in southern Africa increased similar to 80-100 kyr ago while west-central Africa became drier. We hypothesize that these climate differences might be related to the divergent-ancient histories among human populations.

Modelo de Fisher-Kolmogorov em dinâmica populacional com capacidade de suporte espacialmente dependente

Pós-graduação em Física - IFT