Size variation in Tachyoryctes splendens (East African mole-rat) and its implications for late Quaternary temperature change in equatorial East Africa

摘要: Abstract This study develops a new proxy for Quaternary temperature change in tropical Africa through analysis of size variation East African mole-rat (Tachyoryctes splendens). In modern mole-rats, mandibular alveolar length is unrelated to annual precipitation, precipitation seasonality, or primary productivity. However, it inversely correlated with mean temperature, agreement Bergmann's rule. relationship observed at temperatures below ∼17.3 °C, but not higher temperatures. We apply these observations late mole-rats from Wakondo (∼100 ka) and Kisaaka (∼50 ka) the Lake Victoria region Enkapune ya Muto (EYM; ∼7.2–3.2 ka) Kenya's central rift. The are larger than expected populations warm climates typical area today, implying cooler past. magnitude decline needed drive shift substantial (∼4–6 °C), similar degree between Last Glacial Maximum Holocene, consistent regional records scenarios linking equatorial northern hemisphere summer insolation. Size changes time EYM indicate that rising during middle Holocene accompanied potentially contributed Naivasha expansion grassland vegetation.