How many ribs do humans have?
The latest chapter of human evolution begins with the emergence of Homo sapiens. The anatomy of Homo sapiens is unique among hominin species and appears first in East Africa, dating to roughly 160 thousand years ago (ka). These unique features—including changes in the skull and postcranial skeleton (skeleton minus skull)—suggest changes in brain size and architecture and an adaptation to tropical environments. These anatomical changes are linked to cognitive and behavioral changes that are equally unique among hominin species. In particular, the archaeological evidence of behaviors thought to be unique to Homo sapiens, which appear first in Africa around 170 ka, highlight the importance of symbolism, complex cognitive behaviors, and a broad subsistence strategy (the strategy used to procure food). The evolution of Homo sapiens is vitally important to defining our species in the broader context of human evolution and also has key to understanding the human condition, past and present.