Paleoclimate during Neandertal and anatomically modern human occupation at Amud and Qafzeh, Israel: the stable isotope data.

The δ(13)C(en) and δ(18)O(en) values of goat and gazelle enamel carbonate indicate that Neandertals at Amud Cave, Israel (53-70 ka) lived under different ecological conditions than did anatomically modern humans at Qafzeh Cave, Israel (approximately 92 ka). During the Last Glacial Period, Neandertals at Amud Cave lived under wetter conditions than those in the region today. Neither faunal species ate arid-adapted C(4) plants or drought-stressed C(3) plants. The variation in gazelle δ(18)O(en) values suggests multiple birth seasons, which today occur under wetter than normal conditions. The magnitude and pattern of intra-tooth variation in goat δ(18)O(en) values indicate that rain fell throughout the year unlike today. Anatomically modern humans encountered a Qafzeh Cave region that was more open and arid than Glacial Period Amud Cave, and more open than today's Upper Galilee region. Goat δ(13)C(en) values indicate feeding on varying amounts of C(4) plants throughout the year. The climate apparently ameliorated higher in the sequence; but habitats remained more open than at Amud Cave. Both gazelles and goats fed on C(3) plants in brushy habitats without any inclusion of C(4) plants. The magnitude of intra-tooth variation in goat δ(18)O(en) values, however, suggest that some rain fell throughout the year, and the relative representation of woodland dwelling species indicates the occurrence of woodlands in the region. Climate differences affecting the distribution of plants and animals appear to be the significant factor contributing to behavioral differences previously documented between Neandertals and anatomically modern humans in the region. Climate forcing probably affected the early appearances of anatomically modern humans, although not the disappearance of Neandertals from the Levant.