Mechanisms for Speciation inGalago andTarsius

Abstract

Patterson's Recognition Concept of Species has profound implications for the way we analyze the process of species formation. It emphasizes absolute rather than relativistic mechanisms, and concentrates on adaptive processes within population isolates rather than competitive exclusion or competition. Environmental change is seen as a major force initiating speciation. In the case of two species ofGalago, environmental degradation and the breakup of forest blocks is likely to have been the major initiator; while changes in sea-level may have lead to the fragmentation of populations ofTarsius. In both cases, however, the relationships of body size, energetics, heterochrony and species strategies most likely provided the engine for further behavioural and morphological divergence.