Christopher J Bae | University of Hawaii at Manoa (original) (raw)
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Papers by Christopher J Bae
Nature Ecology & Evolution
Journal of Human Evolution
Pongo fossils with precise absolute age brackets are rare, limiting our understanding of their ta... more Pongo fossils with precise absolute age brackets are rare, limiting our understanding of their taxonomy and spatiotemporal distribution in southern China during the Late Pleistocene. Twenty-four isolated teeth of fossil orangutans were recently discovered during excavations at Yicun Cave in Guangxi Zhuang Autonomous Region, southern China. Here, we dated the fossil-bearing layer using Uranium-series dating of the associated flowstone and soda straw stalactites. Our results date the Yicun orangutan fossils to between 66 ± 0.32 ka and 57 ± 0.26 ka; thus, these fossils currently represent the last appearance datum of Pongo in southern China. We further conducted a detailed morphological comparison of the Yicun fossil teeth with large samples of fossil (n ¼ 2454) and extant (n ¼ 441) orangutans from mainland and island Southeast Asia to determine their taxonomic position. Compared to other fossil and extant orangutan samples, the Yicun Pongo assemblage has larger teeth and displays greater variation in occlusal structure. Based on the high frequency of cingular remnants and light to moderate enamel wrinkling of the molars, we assigned the Yicun fossils to Pongo weidenreichi, a species that was widespread in southern China throughout the Pleistocene. Lastly, we used published stable carbon isotope data of Early to Late Pleistocene mammalian fossil teeth from mainland Southeast Asia to reconstruct changes in the paleoenvironment and to interpret dental size variation of Pongo assemblages in a broader temporal and environmental context. The carbon isotope data show that dental size reduction in Pongo is associated with environmental changes. These morphological changes in Pongo appear to coincide with the expansion of savannah biomes and the contraction of forest habitats from the Middle Pleistocene onward. The variation in dental size of forest-dwelling Pongo in mainland Southeast Asia may have resulted from habitat differentiation during the Pleistocene.
Quaternary Science Reviews
Quaternary Geochronology, 2020
Abstract To extend the range of materials that can be used to provide chronological constraint in... more Abstract To extend the range of materials that can be used to provide chronological constraint in archaeological and palaeontological settings, we explore the use of cave pearls that form in shallow pools. Here, we present U-series dating results of cave pearls found in cave sediments with mammal fossils collected from systematic excavations at the Diaozhongyan Cave (“DZY”), located in Guangxi Zhuang Autonomous Region, southern China. Similar to soda straw stalactites, cave pearls can be transported after formation and subsequently incorporated into sediments. Thus, the U-series ages of the outermost layers of cave pearls are expected to be older than their host sediments and associated archaeological and paleontological materials. In conjunction with U-series dating of mammal teeth, which can provide a reliable minimum age, U-series ages of cave pearls can provide a maximum age limit of the deposits. Thus, dating of the mammal teeth and cave pearls from DZY reasonably constrains the first occurrence of the DZY Ailuropoda-Stegodon fauna to a period between 205.6 ± 1.4 ka and 231.0 ± 12.8 ka. These age constraints agree well with previous estimates for the time range of the late Middle Pleistocene Ailuropoda-Stegodon fauna in southern China. We propose that greater attention should be paid to cave pearls, which are commonly found in cave deposits that were laid down at least in part due to fluvial activity, and can be used for U-series dating to better constrain the age of the associated cave deposits.
Palaeogeography, Palaeoclimatology, Palaeoecology, 2018
Quaternary International, 2020
Abstract A number of important early Late Pleistocene human fossils have been found in southern C... more Abstract A number of important early Late Pleistocene human fossils have been found in southern China. These new data have contributed to a major revision of the traditional Out of Africa model that argues modern humans did not disperse out of Africa until after 60 ka. At the same time, these findings have attracted increased attention by paleoclimate specialists (e.g., vertebrate paleontologists, sedimentologists) interested in identifying the characteristics and understanding the living environment of the region in which these early Late Pleistocene modern humans lived in. Unfortunately, research focused on the reconstruction of the Late Pleistocene paleoenvironment in southern China is still very limited. Here, we present an analysis of the clay mineral assemblage and geochemical characteristics of the sedimentary deposits from Luna Cave, one of these important early Late Pleistocene modern human sites in southern China. The results from the sedimentological analyses are consistent with previous paleontological and geological studies that showed the paleoclimate was strongly influenced by the East Asian monsoon and that the Late Pleistocene environment was relatively stable warm and humid. Further studies of coeval sites from the region are necessary to determine whether this is a consistent pattern across southern China or specific to the Bubing Basin.
FIGURE 1 Asimplified model for the evolution of the genus Homo over the last 2 million years, wit... more FIGURE 1 Asimplified model for the evolution of the genus Homo over the last 2 million years, with Homo bodoensis sp. nov. positioned as the ancestral (mostly African) form of Homo sapiens
Evolutionary Anthropology: Issues, News, and Reviews, 2021
Palaeogeography, Palaeoclimatology, Palaeoecology, 2018
Anthropological Science, 2007
Quaternary International, 2014
Radiocarbon: An International Journal of Cosmogenic Isotope Research, 2010
Radiocarbon: An International Journal of Cosmogenic Isotope Research, 2010
Alleged differences between Palaeolithic assemblages from eastern Asia and the west have been the... more Alleged differences between Palaeolithic assemblages from eastern Asia and the west have been the focus of controversial discussion for over half a century, most famously in terms of the so-called ‘Movius Line’. Recent discussion has centered on issues of comparability between handaxes from eastern Asian and ‘Acheulean ’ examples from western portions of the Old World. Here, we present a multivariate morphometric analysis in order to more fully document how Mid-Pleistocene (i.e.,803 Kyr) handaxes from Bose Basin, China compare to examples from the west, as well as with additional (Mode 1) cores from across the Old World. Results show that handaxes from both the western Old World and Bose are significantly different from the Mode 1 cores, suggesting a gross comparability with regard to functionally-related form. Results also demonstrate overlap between the ranges of shape variation in Acheulean handaxes and those from Bose, demonstrating that neither raw material nor cognitive factor...
China Review International, 2015
지난 반 세기동안 척추 동물을 이용한 화석형성학 연구는 고인류학의 복잡하고도 다양한 쟁점에 대한 해결의 실마리를 제공해 왔다. 이러한 학문적 발전 덕에 이제는 유적을 발견했을... more 지난 반 세기동안 척추 동물을 이용한 화석형성학 연구는 고인류학의 복잡하고도 다양한 쟁점에 대한 해결의 실마리를 제공해 왔다. 이러한 학문적 발전 덕에 이제는 유적을 발견했을 때 1) 그 유적이 집자리 유적인지, 2) 석기가 출토되지 않았다고 해서 유적에서 발견된 부러진 뼈나 뿔 그리고 치아가 도구로 사용되었다고 볼 수 있는지, 3) 그 유적에 예술과 상징행위의 증거가 있는지와 같은 질문에 보다 설득력 있는 답을 할 수 있게 되었다. 이 논문에서는 한국의 구석기 고고학 자료를 통해 이러한 여구 주제에 대해 동물고고학 분석이 해 온 역할에 대해 리뷰를 해 보았다. 한국의 경우, 이미 동물고고학계에서 표준으로 인정받고 있는 화석형성학적 방법론이 제대로 적용되지 않은 채 동물뼈에 대한 분석이 이루어진 경우가 많아 이를 통한 과거 인류의 행위 추론 및 해석에 의문이 제기 되어 왔다. 이 리뷰를 통해 필자는 한국의 플라이스토세 동물뼈 자료가 학문적인 중요성을 지니며, 고인류학적 논쟁에 기여를 하기 위해서는 무엇보다도 제대로 된 화석형성학적 이론과 방법론의 적용이 선행되어야 한다고 주장한다.
The Handbook of Mummy Studies
Nature Ecology & Evolution
Journal of Human Evolution
Pongo fossils with precise absolute age brackets are rare, limiting our understanding of their ta... more Pongo fossils with precise absolute age brackets are rare, limiting our understanding of their taxonomy and spatiotemporal distribution in southern China during the Late Pleistocene. Twenty-four isolated teeth of fossil orangutans were recently discovered during excavations at Yicun Cave in Guangxi Zhuang Autonomous Region, southern China. Here, we dated the fossil-bearing layer using Uranium-series dating of the associated flowstone and soda straw stalactites. Our results date the Yicun orangutan fossils to between 66 ± 0.32 ka and 57 ± 0.26 ka; thus, these fossils currently represent the last appearance datum of Pongo in southern China. We further conducted a detailed morphological comparison of the Yicun fossil teeth with large samples of fossil (n ¼ 2454) and extant (n ¼ 441) orangutans from mainland and island Southeast Asia to determine their taxonomic position. Compared to other fossil and extant orangutan samples, the Yicun Pongo assemblage has larger teeth and displays greater variation in occlusal structure. Based on the high frequency of cingular remnants and light to moderate enamel wrinkling of the molars, we assigned the Yicun fossils to Pongo weidenreichi, a species that was widespread in southern China throughout the Pleistocene. Lastly, we used published stable carbon isotope data of Early to Late Pleistocene mammalian fossil teeth from mainland Southeast Asia to reconstruct changes in the paleoenvironment and to interpret dental size variation of Pongo assemblages in a broader temporal and environmental context. The carbon isotope data show that dental size reduction in Pongo is associated with environmental changes. These morphological changes in Pongo appear to coincide with the expansion of savannah biomes and the contraction of forest habitats from the Middle Pleistocene onward. The variation in dental size of forest-dwelling Pongo in mainland Southeast Asia may have resulted from habitat differentiation during the Pleistocene.
Quaternary Science Reviews
Quaternary Geochronology, 2020
Abstract To extend the range of materials that can be used to provide chronological constraint in... more Abstract To extend the range of materials that can be used to provide chronological constraint in archaeological and palaeontological settings, we explore the use of cave pearls that form in shallow pools. Here, we present U-series dating results of cave pearls found in cave sediments with mammal fossils collected from systematic excavations at the Diaozhongyan Cave (“DZY”), located in Guangxi Zhuang Autonomous Region, southern China. Similar to soda straw stalactites, cave pearls can be transported after formation and subsequently incorporated into sediments. Thus, the U-series ages of the outermost layers of cave pearls are expected to be older than their host sediments and associated archaeological and paleontological materials. In conjunction with U-series dating of mammal teeth, which can provide a reliable minimum age, U-series ages of cave pearls can provide a maximum age limit of the deposits. Thus, dating of the mammal teeth and cave pearls from DZY reasonably constrains the first occurrence of the DZY Ailuropoda-Stegodon fauna to a period between 205.6 ± 1.4 ka and 231.0 ± 12.8 ka. These age constraints agree well with previous estimates for the time range of the late Middle Pleistocene Ailuropoda-Stegodon fauna in southern China. We propose that greater attention should be paid to cave pearls, which are commonly found in cave deposits that were laid down at least in part due to fluvial activity, and can be used for U-series dating to better constrain the age of the associated cave deposits.
Palaeogeography, Palaeoclimatology, Palaeoecology, 2018
Quaternary International, 2020
Abstract A number of important early Late Pleistocene human fossils have been found in southern C... more Abstract A number of important early Late Pleistocene human fossils have been found in southern China. These new data have contributed to a major revision of the traditional Out of Africa model that argues modern humans did not disperse out of Africa until after 60 ka. At the same time, these findings have attracted increased attention by paleoclimate specialists (e.g., vertebrate paleontologists, sedimentologists) interested in identifying the characteristics and understanding the living environment of the region in which these early Late Pleistocene modern humans lived in. Unfortunately, research focused on the reconstruction of the Late Pleistocene paleoenvironment in southern China is still very limited. Here, we present an analysis of the clay mineral assemblage and geochemical characteristics of the sedimentary deposits from Luna Cave, one of these important early Late Pleistocene modern human sites in southern China. The results from the sedimentological analyses are consistent with previous paleontological and geological studies that showed the paleoclimate was strongly influenced by the East Asian monsoon and that the Late Pleistocene environment was relatively stable warm and humid. Further studies of coeval sites from the region are necessary to determine whether this is a consistent pattern across southern China or specific to the Bubing Basin.
FIGURE 1 Asimplified model for the evolution of the genus Homo over the last 2 million years, wit... more FIGURE 1 Asimplified model for the evolution of the genus Homo over the last 2 million years, with Homo bodoensis sp. nov. positioned as the ancestral (mostly African) form of Homo sapiens
Evolutionary Anthropology: Issues, News, and Reviews, 2021
Palaeogeography, Palaeoclimatology, Palaeoecology, 2018
Anthropological Science, 2007
Quaternary International, 2014
Radiocarbon: An International Journal of Cosmogenic Isotope Research, 2010
Radiocarbon: An International Journal of Cosmogenic Isotope Research, 2010
Alleged differences between Palaeolithic assemblages from eastern Asia and the west have been the... more Alleged differences between Palaeolithic assemblages from eastern Asia and the west have been the focus of controversial discussion for over half a century, most famously in terms of the so-called ‘Movius Line’. Recent discussion has centered on issues of comparability between handaxes from eastern Asian and ‘Acheulean ’ examples from western portions of the Old World. Here, we present a multivariate morphometric analysis in order to more fully document how Mid-Pleistocene (i.e.,803 Kyr) handaxes from Bose Basin, China compare to examples from the west, as well as with additional (Mode 1) cores from across the Old World. Results show that handaxes from both the western Old World and Bose are significantly different from the Mode 1 cores, suggesting a gross comparability with regard to functionally-related form. Results also demonstrate overlap between the ranges of shape variation in Acheulean handaxes and those from Bose, demonstrating that neither raw material nor cognitive factor...
China Review International, 2015
지난 반 세기동안 척추 동물을 이용한 화석형성학 연구는 고인류학의 복잡하고도 다양한 쟁점에 대한 해결의 실마리를 제공해 왔다. 이러한 학문적 발전 덕에 이제는 유적을 발견했을... more 지난 반 세기동안 척추 동물을 이용한 화석형성학 연구는 고인류학의 복잡하고도 다양한 쟁점에 대한 해결의 실마리를 제공해 왔다. 이러한 학문적 발전 덕에 이제는 유적을 발견했을 때 1) 그 유적이 집자리 유적인지, 2) 석기가 출토되지 않았다고 해서 유적에서 발견된 부러진 뼈나 뿔 그리고 치아가 도구로 사용되었다고 볼 수 있는지, 3) 그 유적에 예술과 상징행위의 증거가 있는지와 같은 질문에 보다 설득력 있는 답을 할 수 있게 되었다. 이 논문에서는 한국의 구석기 고고학 자료를 통해 이러한 여구 주제에 대해 동물고고학 분석이 해 온 역할에 대해 리뷰를 해 보았다. 한국의 경우, 이미 동물고고학계에서 표준으로 인정받고 있는 화석형성학적 방법론이 제대로 적용되지 않은 채 동물뼈에 대한 분석이 이루어진 경우가 많아 이를 통한 과거 인류의 행위 추론 및 해석에 의문이 제기 되어 왔다. 이 리뷰를 통해 필자는 한국의 플라이스토세 동물뼈 자료가 학문적인 중요성을 지니며, 고인류학적 논쟁에 기여를 하기 위해서는 무엇보다도 제대로 된 화석형성학적 이론과 방법론의 적용이 선행되어야 한다고 주장한다.
The Handbook of Mummy Studies