The Pleistocene ( /ˈplaɪstəsiːn/) (symbol P_S) is the geological epoch which lasted from about 2,588,000 to 11,700 years ago, spanning the world's recent period of repeated glaciations. The name Pleistocene is derived from the Greek πλεῖστος (pleistos "most") and καινός (kainos "new").

The Pleistocene epoch follows the Pliocene epoch and is followed by the Holocene epoch. The Pleistocene is the first epoch of the Quaternary Period or sixth epoch of the Cenozoic Era. The end of the Pleistocene corresponds with the end of the last glacial period. It also corresponds with the end of the Paleolithic age used in archaeology.

In the ICS timescale, the Pleistocene is divided into four stages or ages, the Gelasian, Calabrian, Ionian and Tarantian. All of these stages were defined in southern Europe. In addition to this international subdivision, various regional subdivisions are often used.

Before a change finally confirmed in 2009 by the International Union of Geological Sciences, the boundary between the Pleistocene and the preceding Pliocene was regarded as being at 1.806 not 2.588 million years BP; publications from the preceding years may use either definition of the period.

Beth A. Shapiro (born 1976) is an American evolutionary molecular biologist. She has been an Assistant Professor in the Department of Biology at the Pennsylvania State University since 2007. Shapiro's work has centered on the analysis of ancient DNA. She was awarded a MacArthur Fellowship in 2009.

Shapiro was born in Allentown, Pennsylvania and grew up in Rome, Georgia, where she served as the local news anchor while still in high school. She graduated from the University of Georgia in 1999 with both a B.A. and an M.A. in ecology. The same year she was awarded a Rhodes Scholarship. In 2003 Shapiro received a D.Phil. in biology from Oxford University.

Shapiro became a Wellcome Trust Research Fellow at Oxford in 2004. The same year she was appointed director of the Henry Wellcome Biomolecules Centre at Oxford. A position she held until 2007. In 2006 she was awarded a University Research Fellowship by the Royal Society. While at the Biomolecules Centre Shapiro carried out mitochondrial DNA analysis of the dodo.