人骨考古、牙齒型態與DNA親緣關係：以花蓮嶺頂Ⅱ遺址為例

Human Bone Archaeology, Teeth Morphology and DNA Relatedness of Ling-Ting II Sites in Hualien

胡正恆(Hu, Cheng-Heng)

《華岡農科學報》 43期 (2019/06) Pp. 1-27

摘要

史前遺址內的人齒，其生物材料能經歷數千年而能耐久保存。在萃取牙根殘留細胞DNA判定親緣後，更值得探討牙齒表面的發育型態，進行完整的統計分析。花蓮嶺頂Ⅱ號遺址發掘所得的11具墓葬遺留，位處新石器時代中期的繩紋陶文化層，可應用第一手的田野資料分析其牙齒形質與墓葬空間關聯。本研究根據「牙齒再現血緣」假說推論：血緣親近者應反映出類似牙齒表面測量值。在顯微鏡下測量發掘所得之73枚牙齒，主成分分析的二維雙序圖合計解釋94.3%的變異度：第一主成分軸可解釋的變異度達89.0%，主要是正相關於牙齒類型，以及負相關於齒冠琺瑯質橫切面牙寬（BCD）與牙長（MCD）。第二主成分軸之特徵值可解釋的變異度為5.3%，整個模式最大解釋度的變數依序為：牙齒類型＞牙寬（BCD）＞牙長（MCD）＞左右側＞上下顎。驗證五具已知親緣的個體（B1,B2,B4,B5,B11），在近親間呈現較穩定一致的齒冠型態。此外，墓葬B1,B3,B5,B6都沒有拔齒，而牙齒的毀飾習俗只存於B11個體：其二枚下犬齒顯著外突，拔除上犬齒與鄰近一枚門牙，拔齒型態為CI2│CI2，拔牙時間應在青少年時期。相較史前西南台灣所廣泛傳承的拔齒慣俗，此一東台灣少數史前拔齒案例，結合墓葬空間分析、與體質DNA的生物考古學工作，未來可進一步評估當地社會被組織起來的環境生態特色。

關鍵字

東臺灣花蓮 ； 嶺頂II號遺址（LT II） ； 新石器時代中期 ； 墓葬 ； 牙齒 ； 拔齒習俗

並列摘要

Teeth are durable biological materials for thousand years that enable to confirm ancient DNA relatedness and crown morphology. The 11 sets of human remains at the Ling-Ting II site in Hualien were excavated, in which existed in the middle of the Neolithic Age, from 3450 to 3345 years ago (Cal. 1500-1395 BC).After extracting the teeth DNA of the residual cells, it is worthwhile to explore the developmental pattern of tooth surface for a complete statistical analysis. The first-hand field data were used to analyze the tooth measurement and burial space. The hypothesis of ＂DNA-crown association＂ predicts: the closer relatives, the more similar in terms of tooth morphology. In this study, 73 teeth across 10 ancient persons were measured under the high-resolution microscope, and the principal component analysis (PCA) was performed. The biplot totally explains 94.3% of variability: the first principal component axis accounts to 89.0%, mainly related to tooth type and the crown measurement, such as tooth width (BCD) and tooth length (MCD).The eigenvalue of the second axis can explain 5.3% of variability. The significant factors are the following: tooth type＞ tooth width (BCD) ＞ tooth length (MCD) ＞ left / right sides ＞ upper / lower jaws. Five individuals (B1, B2, B4, B5, B11) with known DNA relatedness were validated the hypothesis, showing a more consistent crown morphology among close relatives. In addition, individuals B1, B3, B5, and B6 have no teeth ablation; the tooth removed custom only occurred in the individual B11, when the upper canine tooth and the adjacent one incisor were removed in adolescence, and the tooth ablation type is CI2│CI2. Compared with the southwestern Taiwan since 4,500 years BP, it is worthy to note the similar custom of teeth ablation in East Taiwan during the middle of the Neolithic Age. Combining archaeological fieldwork, cultural analysis, ancient DNA and dental pathology, this study is essential to assess the environmental characteristics and local societal organization.

並列關鍵字

East Taiwan (Hualien) ； Ling-Ting Site (LTII) ； Middle Neolithic Age ； Burial Human Bones ； Teeth Morphology ； Ablation Custom