Punctuated equilibria, rates of change and large-scale entities in evolutionary systems

Abstract

Introduction Archaeology and palaeontology, often confused in the public’s mind, do in fact share more than a common source of data in the earth beneath our feet. Both are charged with documenting the actual results of history-be that history the fruits of the evolutionary process as preserved in the sequence of faunas and floras in the fossil record, or the history of human sociocultural evolution as preserved in the archaeological record. In this paper I wish to seek a still deeper analogy between the two disciplines: as I see it, both archaeology and palaeontology are poised and ready to enter the ranks of what, for want of a better term, we might call ‘functional’ science-conferring an alternative status to their traditional perception as purely ‘historical’ sciences. Asked what is unique and potentially powerful about their data, both archaeologists and palaeontologists generally respond with the simple word ‘time’. As skimpy and scantily incomplete as their data generally are, both disciplines are unique within their larger fields of evolutionary and sociocultural enquiry in providing the exact temporal backdrop against which the actual course of historical events have been played out. Yet it is so that, at least until recently, relatively little in terms of actual contributions to an understanding of evolutionary mechanisms (or simply processes of history) have been forthcoming from these disciplines. This is because the actual processes of change (or, for that matter, of that vastly more common pattern, stasis, meaning stability or virtual lack of change) are commonly held to be understood solely in the short-term phenomena of currently functioning systems. This epistemological assertion-that we can understand processes of stasis and change in both biological and sociocultural systems only by studying the structure and function of currently existing systems (e.g. Dobzhansky, 1937; Carson, 1981, for evolutionary biology)-is usually not distinguished from the ontological claim that those processes and phenomena observed in the short term are both necessary and entirely suficient to account for all historically observed phenomena-including those of the palaeontological and archaeological records. Thus the role of archaeology as well as of palaeontology has been simply to document the actual events of history-leaving to evolutionary biologists (mainly, in the past 50 years, geneticists) and sociocultural theorists working with various aspects of human behaviour and sociocultural organization the task of actually elucidating the mechanisms of stasis and change in those systems.