Final answer:
The first hominin species to leave Africa and then successfully spread through Asia and Europe was Homo erectus, beginning around 1.89 million years ago. The fossil site of Dmanisi complicates this narrative, with evidence suggesting earlier migrations and interconnections between Homo erectus and Homo ergaster.
Step-by-step explanation:
The first hominin species to successfully spread through Asia and Europe after leaving Africa was Homo erectus. This species began migrating out of Africa around 1.89 million years before present and managed to settle in areas of Northern Africa, the Near East, Europe, and East and South Asia over the course of hundreds of thousands of years. Their migrations were possibly driven by climate changes and the pursuit of prey, adapting to different environmental conditions which led to a plethora of human species.
The fossil site of Dmanisi in Georgia presents a complex picture of these migrations. It is believed that by 1.85 million years ago, Dmanisi might have been settled by hominins who possibly represent another link between Homo erectus and Homo ergaster, complicating the narrative of hominin evolution and migration. This discovery leads to reevaluations of settlement dates and raises questions about the migratory sequences within and beyond Africa.