November 7 2019
Early Farmer mobility: how to (and not to) integrate archaeology and genetics
In the last few years, many palaeogenomic papers have caught our interest and changed our view on prehistoric populations. Intuitively, it is assumed that significant changes in genetic signals are associated with historical processes at continental level such as ‘massive’ migrations, population replacement and admixture. However, it is not always clear whether and to what extent genetic alterations correlate with historical events (and were perceived as such by prehistoric populations). A not-hypothesis-based investigation of changes in genetic signals over space and time appears to be problematic as long as the relationship between genetic signal and historical process is not clarified. The mere description of patterns of allele frequency is not only idle, but tends to lead to imaginative narratives, of which archaeological research is already full. This contribution calls for ways to be found to distinguish clearly defined historical models using genetics – but not to use genetic data to generate all sorts of historical models.
Using one of the most pervasive questions in prehistoric archaeology as an example – namely the question of whether the spread of agriculture in Europe was mediated by migration of farmers (demic diffusion) or adoption by indigenous hunter-gatherers (cultural diffusion) – this paper will seek to show what sort of information can be gained from a more rigorous hypothesis-testing framework involving archaeology at all stages of the genetic inference process. Moving towards finer-scale population genetic inference at regional, site-specific or even household levels will not only require more palaeogenomes but archaeologically-informed population models, hypotheses and a deeper integration of archaeology and genetics.