While the Earth is about 4.54 billion years old, all of human civilization has been compressed into a single geological epoch: the Holocene. This has been ongoing for about 11,500 years, predating the first Mesopotamian civilizations for which we have any evidence. Prior to the Holocene was the Pleistocene, which ended with the Younger Dryas cold spell. Actually, the Holocene exists more as a demarcation for the period of geologic time that has included human civilization than as an epoch with an independent definition.
Our best ice core samples extend back 650,000 years: about a third of the way into the Pleistocene, but just a tiny foray into geologic time. Pollen from Lake Tanganyika might take us through the Pliocene (Greek for ‘more new’) and into the Miocene (‘less new’). Perhaps some yet-unanticipated data source will be able to take us further still.
It is amazing what scientists are able to determine from inference and the meticulous collection of data: from the age of the universe to the evolutionary history of the planet.