What about causal mechanisms promoting early hominin dispersal in Eurasia? A research agenda for answering a hotly debated question

Mode and time of the first hominin diffusion in Eurasia, dispersal routes along geographical gradients, and factors promoting such dispersal are a hotly debated matter. Despite the growing amount of data, researchers are still far from deciphering the multifaceted relationships between climate changes and vegetation, fauna, and human evolutionary dynamics during the latest Cenozoic. A number of evidence suggests that it was not only climate, which shaped the evolutionary history of our own genus and affected hominin behaviour and dispersals, and that hominin movements cannot always be placed in the wider context of roughly contemporaneous changes of range of large mammalian taxa. In order to develop a more comprehensive understanding of the generality and underlying causal mechanisms for this complex scenario, a new, more integrated research agenda is recommended which requires the cultural and methodological support of disciplines of apparently remote, specialized sectors, such as geochemistry, sedimentology, geodynamics, palaeontology, palaeoecology, palaeonthropology, palinology, palaeobiology, and phylogeography. As all hypotheses about the environmental effects on evolution depend on temporal correlation, the central challenges should be: to finely resolve the chronological framework, to understand the nature of diachroneity among bioevents across geographical and ecological boundaries, to be able to make correlations between distant sequences, as well as to remove the sometimes confusing taxonomical treatments of some mammalian species, to improve understanding of the ecological settings where hominins evolved through advanced palaeoecological approaches (including both classic ecomorphological analysis and new biological and chemical techniques), and to provide high-resolution and integration of discontinuous climatic data, by developing a large, multidisciplinary database.