Interesting paper by Dr. Stephen Lycett, of the University of Kent, UK, from which the following extract is taken:

In recent years it has been increasingly recognized that the manufacture of artefacts such as handaxes results from the process of social transmission of knowledge between individuals and across generations [18][21]. It is also been increasingly recognized that social transmission may be modeled as a mechanism of inheritance broadly analogous to that of genetic transmission [22][27]. This is not to say that these two inheritance mechanisms are identical in all respects.

One obvious difference is that in the case of social transmission the ability to acquire information is not limited solely to copying biological parents; there is also the opportunity to copy more distantly related kin and unrelated individuals. Nevertheless, attention has increasingly been drawn to the fact that the evolution of cultural traditions involves a process of social inheritance, variation in the details of practice, and differential representation of given variants in subsequent generations (i.e. sorting due to various selection processes and cultural drift) (e.g.[28], [29]). One outcome resulting from recognition of this analogous process has been an increase in the application of population genetic and phylogenetic methods drawn from biology in order to understand the evolution of cultural phenomena, including artefacts (e.g.[10], [30][43]).

The gist of the author’s proposals is that dispersals from Africa dating from the early Pleistocene are thought to have taken place, but there is very little in the way of preserved human fossil remains to confirm this – instead, he suggests that stone hand-axes can to some extent be relied upon as evidence for these dispersals. For a long-term tradition of making hand-axes to exist, some kind of social transmission is assumed, whereby information about how to source material and modify it in order to make stone hand-axes (and other tools/artefacts) would likely be passed on down the generations through time, (as well as across contemporary communities), and this knowledge would gradually spread over geographical space as migrating populations left their homelands and spread from Africa into Europe, the Near East and much of Asia. And although the raw materials often differed across sites, this factor doesn’t appear to have placed a significant constraint on the spread of  Acheulean lithic industry.

However, it is noted that in some locations such as Elveden in England (+Guba video link) and South Asia, the data don’t always conform to the underlying hypothesis, implying that not all tool-makers far from Africa derived their knowledge from ancestral sources, but in some cases invented ostensibly identical technologies themselves. For example the discovery of Acheulean technologies appearing in India where no contemporary human fossils have been found makes it unclear whether this represents a colonisation event, or if instead there was an independent and localised innovation on the part of the unidentified individuals residing there in the Early Pleistocene.

As with all PLoS ONE papers featured here, readers have free and unlimited access to the text and supplementary materials. Comments and ratings of the numerous papers at the PLoS site are encouraged.

Reference: Lycett SJ (2009) Understanding Ancient Hominin Dispersals Using Artefactual Data: A Phylogeographic Analysis of Acheulean Handaxes. PLoS ONE 4(10): e7404. doi:10.1371/journal.pone.0007404

Advertisements