Campo Cerrado — forest or savanna?
Today it is undisputed that living systems contain information for the interpretation of the developmental history or the recent growth potential of an area. The decoding of this information, important for the research on landscapes, can only be managed by consequent clarification of the chorological, population-genetic and autecological particularities of the organisms in the landscapes (MÜLLER 1976, 1977). The importance of this biogeographical concept for the evaluation of our landscapes can be shown using the example of the Campos Cerrados, which are increasingly being considered for exploitation and which were defined either as “forest formations” or “savanna types” from the turn of the century until recent days.
Phytogeographic support tor the theory of Pleistocene forest refuges in the Amazon Basin, based on evidence from distribution patterns in Caryocaraceae, Chrysobalanaceae, Dichapetalaceae and Lecythidaceae
In recent years it has generally been accepted that Amazonia was subject to long dry periods in the late Pleistocene and post-Pleistocene which induced forest cover to a few limited areas or refuges. It has been proposed that the subsequent genetic isolation into separate populations is a mnjor factor in the evolution of the species diversity within the lowland forest of Amazonia. Most of the previous evidence for this theory is based on studies of animals, for example: lizards, butterflies, and birds. Here data are presented to confirm the theory of forest refuges using evidence from phytogeography. Distribution patterns of the lowland species of the woody plant families Caryocaraceae, Chrysobalanaceae, Dichapetalaceae and Lecythidaceae are discussed and concur with the possibility of forest refuges. A map is given of the refuge areas that seem most likely, based on evidence from species distribution of the above plant families. The refuges proposed here correspond closely with the refuge areas proposed by Haffer and Brown rather than the extremely reduced areas proposed by Vanzolini.
Evidence for the Evolution of Unpalatability Through Kin Selection in the Heliconinae (Lepidoptera)
The relative palatabilities of seven species of heliconiine butterflies from Trinidad studied by Brower, Brower, and Collins (1963) correlate with variables directly related to individual dispersal and presumably inbreeding. The more unpalatable a species, the greater the number of geographic races and the higher the probability that populations will form site-specific roosting aggregations indicative of home-range behavior and inbreeding. These correlations are expected if kin selection has been important in the evolution of unpalatability in the Heliconiinae, but not if individual selection has been of overriding importance. The evidence supports the hypothesis that genes responsible for the production of unpalatability gain their advantage in part by having individuals carrying genes identical by descent nearby, so that a predator attacking one of these individuals will learn subsequently to avoid attacking other related individuals in the same area.