Trails and Rhythms

Terra 0 is a tentative hominin world. The fossil evidence is sparse and especially fragmentary. Not until its last days is any technology found and then only through the proxies of cut marks on bones rather than tools. It is, as we saw in Chapter 2, a changing Terra where tectonic activity played a major role in forming potent evolutionary landscapes, and climate progressively became cooler and drier.

By contrast, Terra 1 seems positively sunny – much richer in hominin fossils and archaeological evidence for stone technology and diet change. But drawing up the limits to this Terra is not easy. A burst of climatic variability marks its opening, while it ends with changes to the circulation patterns that drive the low-latitude monsoons. This end point coincides with the current evidence for settlement in Asia 1.8Ma.

Terra 0 was a bigger world than Terra 1 (Figure 4.1a and b). Due to higher temperatures and precipitation, the ecologically productive low latitudes extended further north, providing conditions for the dispersal of apes and monkeys. Terra 0 belonged to the Miocene apes who radiated throughout the expanded arboreal habitats. But, beginning in Terra 0, and exacerbated in subsequent Terrae, the primates saw their ranges shrink due to environmental changes in temperature and moisture. This trend has resulted in today’s distribution of apes and monkeys that are mostly restricted to a tropical refuge zone, a pattern which also holds true in the New World.