Humans, hyenas, and cats: does human evolution in Europe reflect turnovers in carnivore Mammal communities?

In 1994, the discovery of fossil evidence antedating the Matuyama- Brunhes boundary, in sites such as Atapuerca-TD (Spain) and Ceprano (Italy), gave new and unexpected vigour to the hypothesis of a “long chronology” for the earliest dispersal of hominins in Europe. At the turn of the century, the first crania unearthed at Dmanisi (Republic of Georgia), reinforced the idea that early representatives of the genus Homo were capable to reach the “gates of Europe” as early as about 1.75 Ma. More recently, further fossil evidence from Dmanisi and the discovery of very ancient sites with Mode 1 Palaeolithic assemblages both in Italy (e.g., Pirro Nord) and Spain (e.g., Sima del Elefante, Ata- puerca, and sites in the Orce basin) fixed provisionally the earliest Eu- ropean settlements at the mid of the Early Pleistocene. At the same time, our knowledge about human evolution in Europe after the first dispersal and settlements, that is during the Middle and Late Pleisto- cene, greatly benefit from new discoveries and analytical approaches, as well as from the combination between paleontological and paleoge- netic data. Thus, although a number of arguments remains controver- sial, we are now able to depict a scenario of human evolution during the Pleistocene viewed from a European perspective – with its continu- ities and discontinuities, from the earliest inhabitants of the continent up to the Neanderthals and their interaction with modern humans of ultimate African origin. From this scenario, interesting hypothesis may be put forward about the biogeographical interactions with other con- tinental areas, including south-western Asia, Africa, and the Far East. Humans have to be viewed, especially in the Early Pleistocene, as an element of terrestrial ecosystems, and their dispersals have to be con- sidered in the framework of the dispersal events that concerned Mam- mal communities during the Plio-Pleistocene. The interactions with carnivores are of special interest from this perspective, because of the close ecological relationships between humans and predators like hy- enas and large felids. Carnivores are important elements of the disper- sal events from Africa to Europe occurred at the Plio-Pleistocene transition (about 1.8 Ma), with Pachycrocuta brevirostris, Panthera gombaszoegensis and Megantereon whitei, and at the Early-Middle Pleistocene transition (about 0.8 Ma), with Crocuta crocuta, lion and leopard. The latter species replaced the Early Pleistocene top preda- tors, constituting a carnivore guild that characterized Mid-to-Late Pleistocene faunas. The paper is aimed to discuss this composite scenario and evaluate which light can be thrown on both sides of the matter.