Publication Date


Document Type


First Advisor

Orlosky, Frank James, 1943-

Degree Name

M.A. (Master of Arts)

Legacy Department

Department of Anthropology


Natural selection; Primates--Evolution


In this thesis the utility of the r- K-selection continuum model and the punctuated equilibria model of evolution is considered. Both of these concepts are of relatively recent origin and have challenged traditional scientific beliefs by presenting theories of alternative mechanisms operating in nature. Both models are significant for their heuristic effects on evolutionary epistemologies. In the r- K-selection continuum model, originated by Mac Arthur and Wilson (1967), the various processes of natural selection are considered. Natural selection operates through differential fertility and mortality of organisms. It can function in any organism to maximize the amount of energy and resources invested in either reproduction or survival. Therefore, organisms survive and reproduce under relatively different selection regimes. The recognition of different strategies along the r- K-selection continuum among living taxa is presumed to facilitate prediction of potential speciation modes and tempos. In the punctuated equilibria model, originated by Eldredge and Gould (1972), the modes and tempos of speciation are addressed. The model originated as a challenge to a perceived domination of the phyletic gradualism concept in traditional evolutionary thought. Through the punctuated equilibria model, the course of evolution is believed to be one of predominant stasis through time which is sporadically interrupted by rapid evolutionary change through allopatric speciation. The utility of the r- K-selection and punctuated equilibria models is investigated through their application to extant primate taxa. The literature on extant primates is surveyed to reveal expressions of various facets of relative r- to K-strategies. Documented biological, ecological and behavioral data for several primate species are reviewed. A detailed strategic examination of extant Lemur and Papio species is also presented. From these reviews it is asserted that both models can be utilized in formulating hypotheses about primate speciation. Relatively K-selected primates are believed to experience slow speciation; relatively r-selected primates undergo a more rapid, punctuated tempo of speciation. Therefore, with respect to the primates, it is concluded that speciation probably is not a uniform process for all taxa.


Includes bibliographical references.


v, 112 pages




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