Abstract

This paper presents a non-reductionist framework of eight nested modes of evolution that have successively emerged to organize the reproduction of all organisms, from the blue-green algae to our societies. The processes of biological, "Darwinian," evolution are those of drift during reproduction, and of selection. The key unit of evolutionary time is the generation, and its locus is the organisms' life-cycle setup. Different life-cycle setups support different mechanisms of reproduction, and therefore different modes of evolution. By tracing the different life-cycle setups attested throughout Life's History, we are able to characterize the successive modes of evolution with which they are associated. The present attempt has led to a characterization of the following eight nested modes of evolution: Basic; Reptilian; Archaic Mammalian; Progressive Mammalian; Socio-cultural; Extrasomatically Enhanced Socio-cultural; Tinkering; and finally Para-biological. These successively emerging modes govern a progressively reduced number of life-forms. The first four modes are "Darwinian" in the strict sense. The fifth, or socio-cultural mode, which governs whale and elephant societies in addition to hominoids, is already not "Darwinian" in the traditional sense. The last three modes have emerged with the genus homo, through the progressive extension of its life-cycle setups. The present framework is to be used heuristically, as a prism with which to separate the evolutionary spectrum of the constituent elements of human behavior. An example of such a behavioral evolutionary spectrum is presented in the conclusion, and is used to compare the present framework with those recently proposed by Maynard Smith and Szathmáry and by Foley