This topic is a bit tangential to gene-environment interactions. However, it must be kept in mind that climatic periods have always had an important impact on the genome of Homo sapiens during the multiple human migrations “Out of Africa” (i.e. The Great Human Diaspora) during the past ~800,000 years. From ~780,000 to ~12,000 years ago — was the Middle and Late Pleistocene Era, during which anatomically modern humans first evolved. The last Glacial Maximum was ~30,000 years ago, and the last glacial period was 18,000 to 15,000 years ago.
Scientists in July 2o18 announced a new name for the past 4,200 years of geologic history: the Meghalayan age. The declaration by the International Commission on Stratigraphy divides the Holocene (our current, warm, human-dominated epoch) into three ages, based on global changes: the Greenlandian, which started as glaciers retreated 11,700 years ago; the Northgrippian, marked by a cooling trend 8,300 years ago; and the Meghalayan, which began 4,200 years ago with a mysterious drought and cooling trend that coincided with the decline of several civilizations.
Agricultural-based societies that developed in several regions after the end of the last Ice Age were impacted severely by the 200-year climatic event that resulted in the collapse of civilizations and human migrations [in Egypt, Greece, Syria, Palestine, Mesopotamia, the Indus Valley (northwestern regions of South Asia), and Yangtze River Valley, and the west coast of what is now Bolivia and Peru). The Meghalayan’s marker in the rock record — called the “golden spike” — comes from oxygen isotopes found in a stalagmite from the Meghalaya plateau in northeast India. The newly defined age names and dates provide standardized versions of divisions that scholars had long drawn between an early, middle, and late Holocene.
The commission has not yet finished a study of whether the planet, by about the 1950s, left the Holocene and entered a new geological epoch — proposed to be the Anthropocene (because it has been suggested by some to be ‘dominated by human influence’). This remains controversial.
Science 27 Jul 2o18; 361: 315