Big History seeks to understand the integrated history of the Cosmos, Earth, Life, and Humanity, using the best available empirical evidence and scholarly methods.
Beginning about 13.8 billion years ago, the story of the past is a coherent record that includes a series of great thresholds. Beginning with the Big Bang, Big History is an evidence-based account of emergent complexity, with simpler components combining into new units with new properties and greater energy flows.
The Beginning and Development of Culture
Through our culture, humans shaped some of the natural forces from which we emerged. We added hunting to scavenging and gathering. Beginning about 70,000 years ago, we left our African home and migrated throughout the globe, crossing Beringia into the Americas some 20,000 years ago (though the precise date is still heavily debated). We formed bands, kinship groups, villages, chiefdoms, cities, nations, and empires. Our species crossed other major thresholds with the emergence of agricultural states, the burning of fossil fuels, and the recent entrance into an information-rich, digital era.
We have fought many wars among ourselves and brought about environmental degradation and resource depletion. These and other problems threaten the quality and even survival of our species. We face a current crisis and a possible loss of complexity. Over 99% of the species that have ever existed are now extinct. No complex species is likely to survive intact for more than a few million years; we will be lucky if we survive that long.