A global atmospheric general circulation model and an asynchronously coupled global atmosphere-biome model are used to simulate vegetation feedback at the mid-Pliocene approximately 3.3 to 3.0 million years ago.For th...A global atmospheric general circulation model and an asynchronously coupled global atmosphere-biome model are used to simulate vegetation feedback at the mid-Pliocene approximately 3.3 to 3.0 million years ago.For that period,the simulated vegetation differed from present conditions at 62% of the global ice-free land surface.Vegetation feedback had little overall impact on the global climate of the mid-Pliocene.At the regional scale,however,the interactive vegetation led to statistically significant increases in annual temperature over Greenland,the high latitudes of North America,the mid-high latitudes of eastern Eurasia,and westem Tibet,and reductions in most of the land areas at low latitudes,owing to vegetation-induced changes in surface albedo.展开更多
In the mid-latitude regions of the Asian continent, Zhuye Lake is located in the northwest margin of the Asian monsoon, where the modem climate is affected by the Asian monsoon and Westerlies. In this study, we invest...In the mid-latitude regions of the Asian continent, Zhuye Lake is located in the northwest margin of the Asian monsoon, where the modem climate is affected by the Asian monsoon and Westerlies. In this study, we investi- gated the absolutely dated Holocene records in Zhuye Lake for detecting the Holocene climate cycles. Totally, 14 14C dates and 6 optically simulated luminescence (OSL) dates are obtained from the QTH01 and QTH02 sections. The proxies of grain-size, total organic carbon content (TOC), C/N and 813C are used for wavelet analysis, and the results show obvious -256, -512 and -1024-year climate cycles, which are consistent with the Holocene millennial and cen- tennial scale climate cycles in the typical Asian summer monsoon domain. In different parts of the Zhuye Lake, the Holocene sediments show variable climate cycles that are affected by the lake basin topography. In the Zhuye Lake, the Holocene climate cycles are mainly correlated with the solar-related Asian summer monsoon variability and the North Atlantic ice-rafting events.展开更多
Mummified fossils are extraordinarily important for understanding both biotic evolution and ecology in the geological time,by uniquely providing a far more detailed source of information in comparison to impression ma...Mummified fossils are extraordinarily important for understanding both biotic evolution and ecology in the geological time,by uniquely providing a far more detailed source of information in comparison to impression materials.However,mummified fossils are extremely rare because of the inevitable requirement of unusual preservation conditions during fossilization,including the lithological features and deposition rate of surrounding rocks,and moisture and temperature conditions(Taylor et al.,2009).To date,only a few Cenozoic sites have been reported to yield mummified plant fossils around the world,展开更多
The geographical and climatic patterning in craniofacial morphology among recent hominids has been regarded as relatively reliable evidence of environmental adaptation and natural selection,which is largely attributed...The geographical and climatic patterning in craniofacial morphology among recent hominids has been regarded as relatively reliable evidence of environmental adaptation and natural selection,which is largely attributed to thermoregulation.However,the relative influence of genetic and environmental factors on craniofacial features is unclear.Our study employed 3D laser scanning techniques to evaluate the association between geographical(latitude),climatic(annual temperature)factors,and 3D craniofacial measurements in 18 recent populations through bivariate correlation analysis.Significant correlations were found among braincase surface area,zygomatic bone surface area,cranial-facial index(facial surface area relative to braincase surface area)and local temperature,and a clear latitudinal gradient was also found in variation of braincase surface area.No significant correlations were found between zygomatic bone surface area,cranial-facial index and latitude.Our analysis supports the idea that the braincase functions as a radiator and is closely related to direct sunlight.We also suggest that absolute/relative craniofacial surface area varies consistently with predictions derived from Bergmann’s Rule.The mosaic craniofacial traits of American Indians may reflect retention of cold-derived,ancestral features,as well as a response to a slightly warmer climate.Because different craniofacial regions preserve environmental/genetic signatures differentially,caution is suggested when craniofacial anatomy is used for phylogenetic reconstruction and functional-morphological analysis.展开更多
基金supported by the Knowledge Innovation Program of the Chinese Academy of Sciences(KZCX2-EW-QN202)the National Natural Science Foundation of China(40975050 and41175072)
文摘A global atmospheric general circulation model and an asynchronously coupled global atmosphere-biome model are used to simulate vegetation feedback at the mid-Pliocene approximately 3.3 to 3.0 million years ago.For that period,the simulated vegetation differed from present conditions at 62% of the global ice-free land surface.Vegetation feedback had little overall impact on the global climate of the mid-Pliocene.At the regional scale,however,the interactive vegetation led to statistically significant increases in annual temperature over Greenland,the high latitudes of North America,the mid-high latitudes of eastern Eurasia,and westem Tibet,and reductions in most of the land areas at low latitudes,owing to vegetation-induced changes in surface albedo.
基金Under the auspices of National Natural Science Foundation of China (No. 41001116)Fundamental Research Funds for the Central Universities (No. LZUJBKY-2010-99)
文摘In the mid-latitude regions of the Asian continent, Zhuye Lake is located in the northwest margin of the Asian monsoon, where the modem climate is affected by the Asian monsoon and Westerlies. In this study, we investi- gated the absolutely dated Holocene records in Zhuye Lake for detecting the Holocene climate cycles. Totally, 14 14C dates and 6 optically simulated luminescence (OSL) dates are obtained from the QTH01 and QTH02 sections. The proxies of grain-size, total organic carbon content (TOC), C/N and 813C are used for wavelet analysis, and the results show obvious -256, -512 and -1024-year climate cycles, which are consistent with the Holocene millennial and cen- tennial scale climate cycles in the typical Asian summer monsoon domain. In different parts of the Zhuye Lake, the Holocene sediments show variable climate cycles that are affected by the lake basin topography. In the Zhuye Lake, the Holocene climate cycles are mainly correlated with the solar-related Asian summer monsoon variability and the North Atlantic ice-rafting events.
基金the National Natural Science Foundation of China (Grant Nos. 41210001, 41372002 & 41528201)National Basic Research Program of China (Grant No. 2012CB822003)
文摘Mummified fossils are extraordinarily important for understanding both biotic evolution and ecology in the geological time,by uniquely providing a far more detailed source of information in comparison to impression materials.However,mummified fossils are extremely rare because of the inevitable requirement of unusual preservation conditions during fossilization,including the lithological features and deposition rate of surrounding rocks,and moisture and temperature conditions(Taylor et al.,2009).To date,only a few Cenozoic sites have been reported to yield mummified plant fossils around the world,
基金supported by the Chinese Academy of Sciences (Grant Nos. KZZD-EW-03, XDA05130100, GJHZ201314)the National Natural Science Foundation of China (Grant No. 41272034)
文摘The geographical and climatic patterning in craniofacial morphology among recent hominids has been regarded as relatively reliable evidence of environmental adaptation and natural selection,which is largely attributed to thermoregulation.However,the relative influence of genetic and environmental factors on craniofacial features is unclear.Our study employed 3D laser scanning techniques to evaluate the association between geographical(latitude),climatic(annual temperature)factors,and 3D craniofacial measurements in 18 recent populations through bivariate correlation analysis.Significant correlations were found among braincase surface area,zygomatic bone surface area,cranial-facial index(facial surface area relative to braincase surface area)and local temperature,and a clear latitudinal gradient was also found in variation of braincase surface area.No significant correlations were found between zygomatic bone surface area,cranial-facial index and latitude.Our analysis supports the idea that the braincase functions as a radiator and is closely related to direct sunlight.We also suggest that absolute/relative craniofacial surface area varies consistently with predictions derived from Bergmann’s Rule.The mosaic craniofacial traits of American Indians may reflect retention of cold-derived,ancestral features,as well as a response to a slightly warmer climate.Because different craniofacial regions preserve environmental/genetic signatures differentially,caution is suggested when craniofacial anatomy is used for phylogenetic reconstruction and functional-morphological analysis.