New immature hominin fossil from European Lower Pleistocene shows the earliest evidence of a modern human dental development pattern
New immature hominin fossil from European Lower Pleistocene shows the earliest evidence of a modern human dental development pattern
复制标题
DOI：
10.1073/pnas.1006772107
复制
发表时间：
2010-06-29
影响因子：
11.1
通讯作者：
Carbonell, Eudald
中科院分区：
文献类型：
--
作者：
Bermudez de Castro, Jose Maria;Martinon-Torres, Maria;Carbonell, Eudald
在这里，我们提供了有关牙齿发育模式的数据，这些数据来自对最近发现的未成熟的人类下颌骨的显微计算机断层扫描 (microCT) 研究，该下颌骨具有混合牙列，该下颌骨是从西班牙北部阿塔普埃尔卡山脉的格兰多利纳下更新世洞穴遗址的 TD6 水平恢复的。这些数据证实了我们之前的结果，即近 100 万年前，至少一种欧洲古人类物种具有完全现代的牙齿发育模式，前牙区的磨牙区发育明显放缓。此外，利用关于黑猩猩、早期人类和现代人类牙釉质形成时间和牙根延伸率的现有信息，我们估计TD6个体5（H5）的上下第一磨牙的形成时间在5.3至6.6年之间，该个体在死亡时刚刚萌出。因此，TD6古人类第一恒磨牙（M1）的萌出时间在现代人类群体的变异范围内。由于灵长类动物 M1 爆发的时间是生命史的有力标志，因此作为一个可行的假设，我们认为这些古人类在现代人类的变异范围内拥有较长的童年期。如果这一假设成立，则意味着人类这种重要的发育生物学特征的出现以及相关的大脑尺寸的增加先于新皮质区域的发育，从而产生了被认为是智人独有的认知能力。
Here we present data concerning the pattern of dental development derived from the microcomputed tomography (microCT) study of a recently discovered immature hominin mandible with a mixed dentition recovered from the TD6 level of the Gran Dolina Lower Pleistocene cave site in Sierra de Atapuerca, northern Spain. These data confirm our previous results that nearly 1 million years ago at least one European hominin species had a fully modern pattern of dental development with a clear slowdown in the development of the molar field regarding the anterior dental field. Furthermore, using available information about enamel formation times and root extension rates in chimpanzees, early hominins, and modern humans, we have estimated that the formation time of the upper and lower first molars of individual 5 (H5) from TD6, which had just erupted at the time of the death of this individual, ranges between 5.3 and 6.6 y. Therefore, the eruption time of the first permanent molars (M1) in the TD6 hominins was within the range of variation of modern human populations. Because the time of M1 eruption in primates is a robust marker of life history, we suggest, as a working hypothesis, that these hominins had a prolonged childhood in the range of the variation of modern humans. If this hypothesis is true, it implies that the appearance in Homo of this important developmental biological feature and an associated increase in brain size preceded the development of the neocortical areas leading to the cognitive capabilities that are thought to be exclusive to Homo sapiens.