Cradles of diversity are unlikely relics of regional climate stability

The stability of regional climates on millennial timescales is theorised to be a primary determinant of nearby diversification 1, 2, 3, 4, 5. Using simulated patterns of past temperature change at monthly timescales [6], we show that the locations of climatically stable regions are likely to have varied considerably across and within millennia during glacial–interglacial cycles of the Late Quaternary. This result has important implications for the role of regional climate stability in theories of speciation, because long-term climate refugia are typically presumed to be 'cradles' of diversity (areas of high speciation) only if they remain stable across Milankovitch climate oscillations 1, 2, 3, 4, 5, which operate on multi-millennial time scales.