The Theory
During the current ice age, the Pleistocene Epoch, which began 2 million years ago, and can be expected to last another 26 million years; there have been 7 glacial periods averaging 56,000 years apiece. Each of these glacial periods has been followed by an interglacial period averaging 44,000 years apiece, except for the last and current interglacial, called the Holocene, which only began 18,000 years ago.

Glacial periods are not to be confused with Ice ages. All 5 ice ages prior to the Pleistocene lasted anywhere from 140 to 190 million years in duration, making it ludicrous to think that the Pleistocene began 2 million years ago and ended 18,000 years ago.