Newell Elizabeth A, Guatelli-Steinberg Debbie, Field Michelle, Cooke Catherine, Feeney Robin N M
Department of Sociology and Anthropology, Elizabethtown College, Pennsylvania 17022, USA.
Am J Phys Anthropol. 2006 Oct;131(2):252-60. doi: 10.1002/ajpa.20436.
Linear enamel hypoplasia (LEH), a developmental defect of enamel, increases in frequency from prosimian to monkey to lesser ape to great ape grades (Guatelli-Steinberg 2000 Am. J. Phys. Anthropol. 112:395-410, [2001] Evol. Anthropol. 10:138-151; Newell 1998 Ph.D. dissertation, Temple University). This taxonomic pattern in the distribution of LEH is closely related to maturation length across the primate order (Newell 1998 Ph.D. dissertation, Temple University, 2000 Am. J. Phys. Anthropol. [Suppl.] 30:236). Longer maturation periods are associated with higher LEH frequencies; they appear to provide greater opportunity for defects to form. The present study explores the relationship between maturation length and LEH frequency within the Ceboidea. Because of its prolonged period of growth, Cebus is predicted to manifest LEH at a higher frequency than the more rapidly maturing ceboid genera. To test this hypothesis, two separate researchers (E.A.N. and D.G.-S.) examined LEH in nonoverlapping museum series of ceboids. The results support the hypothesis: in 13 genera (n = 1,276), E.A.N. found that LEH frequencies ranged from 0% in Callicebus, Cebuella, and Saimiri to 20% in Cebus. D.G.-S. found similar frequencies among five genera (n = 107), from 0% in Saimiri to 32% in Cebus. Thus, the broad pattern of LEH distribution evident across major taxonomic groups of primates is repeated within the Ceboidea. We also examined a related hypothesis linking the spacing of perikymata, which is influenced by enamel extension rates (Shellis 1998 J. Hum. Evol. 35:387-400), to LEH. The most likely areas of tooth crowns to exhibit LEH in human teeth are those in which perikymata are most closely spaced (Hillson and Bond 1997 Am. J. Phys. Anthropol. 104:89-103). We hypothesized that the longer-maturing Cebus, with its elevated LEH frequency, will also exhibit more closely spaced perikymata than other ceboids. Analysis of a small microscopic subsample (n = 8) lends limited support to this second hypothesis.
线性釉质发育不全（LEH）是一种釉质发育缺陷，其出现频率从原猴到猴、再到小猿和大猿逐渐增加（瓜泰利 - 斯坦伯格，2000年，《美国体质人类学杂志》112:395 - 410，[2001年]《进化人类学》10:138 - 151；纽厄尔，1998年，坦普尔大学博士论文）。LEH分布的这种分类模式与灵长目动物的成熟时长密切相关（纽厄尔，1998年，坦普尔大学博士论文；2000年，《美国体质人类学杂志》[增刊]30:236）。较长的成熟期与较高的LEH频率相关；它们似乎为缺陷形成提供了更多机会。本研究探讨了阔鼻猴超科中成熟时长与LEH频率之间的关系。由于僧帽猴的生长周期较长，预计其表现出LEH的频率会高于成熟速度更快的阔鼻猴属。为了验证这一假设，两位独立的研究人员（E.A.N.和D.G.-S.）检查了阔鼻猴博物馆收藏中不重叠的样本的LEH情况。结果支持了这一假设：在13个属（n = 1276）中，E.A.N.发现LEH频率从伶猴属、侏狨属和松鼠猴属的0%到僧帽猴属的20%不等。D.G.-S.在5个属（n = 107）中发现了类似的频率，从松鼠猴属的0%到僧帽猴属的32%。因此，在灵长目主要分类群体中明显的LEH分布广泛模式在阔鼻猴超科中也有体现。我们还检验了一个相关假设，该假设将受釉质延伸率影响的釉面横纹间距（谢利斯，1998年，《人类进化杂志》35:387 - 400）与LEH联系起来。人类牙齿中最有可能出现LEH的牙冠区域是釉面横纹间距最紧密的区域（希尔森和邦德，1997年，《美国体质人类学杂志》104:89 - 103）。我们假设成熟时间较长、LEH频率较高的僧帽猴，其釉面横纹间距也会比其他阔鼻猴更紧密。对一个小的微观子样本（n = 8）的分析为这第二个假设提供了有限的支持。
