Modelos ecológicos e extinção da megafauna no pleistoceno

Abstract

The extinction of megafauna in the pleistocene has been traditionally explained by environmental changes or overexploitation by human hunting (overkill). Despite difficulties in choosing between these alternative (and not mutually exclusive) scenarios, the plausibility of overkill hypothesis can be established by ecological models os predator-prey interactions. In this paper, we developed a macroecological model for overkill hypothesis, in which prey population dynamic parameters, including abundance, geographic extent and food suply for hunters, we derived by empirical allometric relationship with body mass. The final output correct predicts the final destiny (survival or extinction) for 73% of the species, a value only slight smaller than those obtained by more complex models based on more detailed archeological and ecological data for each species. This illustrated the high selectivity os Plestiocene extinction in relation to body mass and gives more plausibility for the overkill scenario.