The ecology of social transitions in human evolution

Abstract

We know that there are fundamental differences between humans and living apes, and also between living humans and their extinct relatives. It is also probably the case that the most significant and divergent of these differences relate to our social behaviour and its underlying cognition, as much as to fundamental differences in physiology, biochemistry or anatomy. In this paper, we first attempt to demarcate what are the principal differences between human and other societies in terms of social structure, organization and relationships, so that we can identify what derived features require explanation. We then consider the evidence of the archaeological and fossil record, to determine the most probable context in time and taxonomy, of these evolutionary trends. Finally, we attempt to link five major transitional points in hominin evolution to the selective context in which they occurred, and to use the principles of behavioural ecology to understand their ecological basis. Critical changes in human social organization relate to the development of a larger scale of fission and fusion; the development of a greater degree of nested substructures within the human community; and the development of intercommunity networks. The underlying model that we develop is that the evolution of 'human society' is underpinned by ecological factors, but these are influenced as much by technological and behavioural innovations as external environmental change.

Mosaic evolution and the pattern of transitions in the hominin lineage

“…This could be summed up as the evolution of H. sapiens, but as some of the traits are shared by the Neanderthal lineage, then it may be a phase that covers both the shift to an ancestor of all larger brained Homo, and uniquely to modern humans, depending on the traits [82]. This Late Quaternary transition is centred on major behavioural, cognitive and cultural changes [83,84] (and references therein). There is a substantial increase in brain size across the period, and changes in cranial morphology and overall robusticity, but compared with the physical changes taking place in the earlier transitions, these are relatively minor.…”

Male tolerance and male–male bonds in a multilevel primate society

“…Strikingly, men from different family groups may form long-term alliances within the community, resulting in cooperative relationships among individuals who often are not genetic relatives (3). The advent of such exceptional cooperative relationships within human societies has been linked to their multilevel organization (4). However, what are the evolutionary dynamics that give rise to multilevel systems in the first place, and how do social organization and cooperative tendencies stabilize each other?…”

Use wear analysis of quartzite lithic implements from the Middle Palaeolithic site of Lagoa do Bando (Central Portugal)

“…This data may suggest a long term occupation. On the other hand, if the hearths were social spaces and the center of the activities (Foley & Gamble 2009;Rosell et al 2012;Vallverdú et al 2012;Vaquero & Pastó 2001), their absence in Lagoa do Bando together with the small quantity of lithic artifacts found, could suggest that the site is an ephemeral occupation site (such consideration remains to be confirmed through future excavations). Considering the available data in our opinion, the Lagoa do Bando remains might be related to two (or more) ephemeral and specialized occupations of the site (Stiner 2013).…”