Lasting from about 3 million to 10,000 years ago, the Pleistocene is both a geological epoch and an idea, write science historians Stephen Pyne (Voyager: Exploration, Space, and the Third Great Age of Discovery, 2011, etc.) and his daughter Lydia, who proceed to deliver a perceptive account of both.
The geological story opens as the unusually wet, warm and homogenized Earth of the Miocene and Pliocene epochs segued into a cooler, drier and more fragmented Pleistocene. Rising mountains and new land bridges (Panama, the Bering Strait) forced a realignment of planetary climate. Ice ages waxed and waned. Many hominid species wandered Africa; several wandered north, but by 50,000 years ago, all except ours had vanished. The idea of the Pleistocene began in the 17th century with the first natural philosophers (“scientist” was a 19th-century invention). Rocks and fossils had been known for millennia, but these men looked with a critical eye. By the 1700s it was obvious that the Earth was old. During the 1800s, this age lengthened and subdivisions proliferated as scientists deciphered sedimentary rock strata, precisely classified fossils, and uncovered the effects of glaciation. After 1900, they argued over African climate change and proliferating hominid species, reveling in a flood of new information from fossil discoveries, plate tectonics, deep ocean cores and vastly improved chemical and radiometric dating. The idea is still evolving.
Readers with a good introduction to the subject under their belt—e.g., Ian Tattersall’s Masters of the Planet (2012)—will be best prepared to absorb this rich but often dense flood of geologic, geographic, anthropologic and philosophical analyses of recent evolution.