1.2 Symbiogenesis, constraint and evolutionary theory

Ecology and evolutionary biology parted company in the 1940s and many developments in the former have had little impact on the latter. Symbiogenesis, for example, the theory that multicellular organisms evolved by a creative synergy between different classes of micro-organism (Margulis 1970), implies that evolutionary synergetics and inter-species co-operation played a crucial role in the evolution of all life-forms with nucleated cells and mitochondria. The systems revolution also focused attention on synergetic processes, agency and self-organisation, developments that proved difficult to reconcile to the gene-centred model.

In order to bridge this gap, we must extend the modern synthesis in ways that accommodate two types of dynamic process. The first is a catastrophic winnowing of failures that drives rapid, directional change; the second takes place in stable attractors. Independent research on natural and human activity systems suggests that complex systems, when they become unstable, can flip from one attractor to another rather quickly, but may dwell in a stable attractor for extended periods. These 'stick-slip' or non-linear dynamics can only become manifest in situations where competitive and synergetic dynamics are both possible and systems can move from one type of dynamic to the other.

For many decades biologists and palaeoanthropologists have been trying to understand fitness in terms of competitive superiority and genes, a model that can accommodate directional change but struggles to represent co-operative synergy. Social anthropologists and archaeologists have often challenged that worldview by equating it with cultural imperialism and drawing attention to the ethical dimensions of eugenic research. This critique misfired because relatively few biologists have imperialistic ambitions and most are frankly baffled by the suggestion that they have. They often dismiss critique as the product of cultural relativism and/or professional jealousy (see, for example, Wilson 1998, chapter 9). The strongest reason for embracing gene-centred, competitive models of natural selection is that competitive constraints, where they occur, would reduce systemic complexity and present the scientist with a tractable research problem.

In general, disciplines tend to preserve simplistic theories as long as the corresponding problem-lode holds out. Often they hold onto them a little longer, while pressure builds for reform, power struggles are resolved and scientific institutions are restructured (Kuhn 1962). Archaeology and social anthropology ran out of problems that could be solved by the heroic model rather early, but the reserves of tractable problems were rather richer in zoology and microbiology. Recurrent arguments about the modern synthesis itself (Gould 1982; Tattersall 2000; Foley 2001), sociobiology (responding to Wilson 1975), dual inheritance (Boyd and Richersen 1982) and studies of human uniqueness (Cartmill et al. 1986; Cartmill 1990) all suggest a paradigmatic tension between the heroic and synergetic models in biological anthropology - a tension that centres on the interface of ecology and evolution.

There is now growing evidence of a paradigmatic realignment in mainstream biology, where the modern synthesis is increasingly presented as a 'special' theory that has been generalised to situations where the evidence doesn't line up. We need a more general, extended synthesis (Pigliucci and Muller 2010) that gives proper weight to agency, co-operation, emergence, trait-mosaics, non-adaptive change, epigenetics and reticulated evolution (Jablonka and Lamb 2005; Arnold 2009; Kivell et al. 2011; Nei and Nozawa 2011). At least two special issues of scientific journals have reviewed the changing state of the art (Noble et al. 2013; Vane-Wright 2014, see also the following, more philosophical discussion). It is not necessary to re-state the case for an extended synthesis here.

This article about complexity, compassion and self-organisation in human activity systems has been written for two purposes. The first is to brief archaeologists about the extent and nature of the paradigmatic revolution in evolutionary biology. We believe that many of the most challenging barriers to integrating the humanities and biology are weakening, and a window of opportunity has opened for co-operative research that did not exist a decade ago. Every prehistorian, whether or not they wish to be involved in this integrative revolution, should be aware of these developments because they change the way we interpret the results of genetic studies in archaeology. Our second reason for writing is to formulate an alternative model of human evolution as a self-organising process, shaped by agency, co-operation and compassion. This article will look for the antecedents of the extended synthesis in early evolutionary literature. The paradigmatic fault lines of evolutionary anthropology can be traced back to the 19th and early 20th centuries. By revisiting older work we can sidestep many of the technicalities of molecular science and focus on the complex relationship between synergetic and heroic processes.