全新世中国人脑形态的微观演化研究

The microevolution of Chinese human brain during the Holocene

目的对比分析不同时代人类颅内模的表面形态,探讨全新世人类脑形态特征的微观进化。方法本实验首先获得592例现代中国人和81例新石器时代人类颅骨的三维CT数据,然后运用Amira软件对这些三维CT数据进行分割,进而三维重建颅骨和颅内模;为了保证颅内模的标准测量,颅骨的空间位置与法兰克福平面一致;颅内模的测量指标代表脑的形态和结构,主要测量值和指数包括脑高、脑宽、脑长、颅容积和额叶高、额叶弦长、额叶宽、大脑高、顶叶弦长以及高宽比值、高长比值、宽长比值和额叶宽与脑宽比值。测量数据运用SPSS17.0软件进行统计分析。结果13项测量指标中,现代人的额叶宽、脑长、额叶宽与脑宽比值大于新石器时代人类,新石器时代人类的颅容积、脑高、额叶高、额叶弦长、顶叶弦长(女性此项相反)、高长比值和高宽比值大于现代人,余指标没有明显差异。结论从新石器时代到现代,人类脑的结构发生了明显的改变。

Objective To reveal the microevolution of human brain during Holocene by comparing threedimensional computed tomographic reconstructions of endocasts taken from both Neolithic and modern-day humans. Methods To address this issue,we collected the cranial computed tomography images of 592 modern adult humans and 81 Neolithic skulls. All the original CT data were imported into Amira software to obtain the three-dimensional skull and endocasts,which were placed in the standard position. The standardized measurements and indices were taken to provide quantification of the overall endocast shape,including cranial capacity,the length,breadth,height,frontal breadth and so on. All data were analyzed with SPSS 17. 0statistical software. Results Various changes in the thirteen measurements and indices of the endocasts between our two samples were observed. The differences were statistically significant for cranial capacity,height,frontal breadth,length,the ratios of frontal breadth to breadth,height to breadth and height to length,frontal height,frontal chord and parietal chord between Neolithic humans and modern-day humans.On the contrary,there were no statistically significant differences for cerebral height,breadth,and the ratio of breadth to length between our two samples. Conclusion Cerebral structure has changed between two Chinese samples from Neolithic humans and from living humans.