INTRODUCTION

In this chapter, I will review the course of human evolution, and examine possible interactions between hominids and their environments, as these are affected by climatic change, at five important stages:

1. The origin of hominines;

2. The origins of the genera Homo and Paranthropus;

3. The dispersal of early humans to Eurasia;

4. The evolution of the Neanderthals;

5. The origin and dispersal of modern humans.

The basic course of human evolution as understood today is represented in Fig. 25.1. An Early Pliocene radiation of bipedal, but ape-like, australopithecines was followed by the Late Pliocene evolution of two more derived clades, perhaps under the influence of drier environments produced by increasing glaciation, or uplift in East Africa. The ‘robust australopithecines’ (genus Paranthropus) underwent gnathic and dental specialization, probably for small hard object feeding (e.g. seeds, nuts), while the other clade became more omnivorous and encephalized, leading to the origin of the genus Homo. An early Homo species dispersed from Africa, probably during the terminal Pliocene, and its descendants are represented by the Homo erectus fossils of eastern Asia and Indonesia. However, the colonization of Europe may have been a Pleistocene event accompanied by amplification of the glacial–interglacial cycles, and while erectus persisted in the East, a new species, Homo heidelbergensis, evolved in Europe and/or Africa during the Mid Pleistocene.