Douglas R J, Marcellus D
Brain Behav Evol. 1975;11(3-4):179-213. doi: 10.1159/000123632.
This paper attempts to investigate taxonomic and phylogenetic relationships through an analysis of the distribution of mass within the brain. A multivariate analysis was performed on encephalization ratios for various divisions of the brain, employing volume measurements reported for 63 species by Stephan et al. [1970]. The ratios for each brain region were considered to lie along one of the dimensions of eight dimensional 'brain space', and distances between all species were calculated and employed in the determination of 'family trees'. It was assumed that modern species have, in many cases, brains representative of different stages of an evolutionary progression towards higher encephalization, and it was assumed that no 'backwards evolution' occurred. The family trees based on these data and assumptions were rigidly determined and do not represent mere opinion but, rather, inescapable conclusions if one accepts the premises. Most of the findings were in very good agreement with traditional or popular ideas, and this includes conclusions that tree shrews were ancestral to prosimians and that simians are derived from a tarsioid ancestor. Other findings, however, were just as strikingly deviant from current popular and expert thought. Present methods demanded, for example, that man must have a platyrrhine ancestry. While one may reject this particular conclusion it remains true that by present measures the human brain is much more like that of an American wooley or spider monkey than like that of either the chimpanzee or the gorilla.
本文试图通过分析大脑内质量分布来研究分类学和系统发育关系。利用斯蒂芬等人[1970年]报告的63个物种的体积测量数据，对大脑各部分的脑化率进行了多变量分析。每个脑区的比率被认为位于八维“脑空间”的一个维度上，并计算了所有物种之间的距离，用于确定“族谱”。假定在许多情况下，现代物种的大脑代表了向更高脑化进化进程的不同阶段，并且假定没有发生“逆向进化”。基于这些数据和假设的族谱是严格确定的，并非仅仅代表观点，而是如果接受这些前提，就会得出不可避免的结论。大多数研究结果与传统或流行观点非常一致，这包括树鼩是原猴亚目的祖先以及猿猴是从跗猴型祖先演化而来的结论。然而，其他研究结果却与当前流行观点和专家看法存在显著偏差。例如，目前的方法认为人类必定有阔鼻猴类的祖先。虽然有人可能会拒绝这一特定结论，但通过目前的测量方法，人类大脑确实更像美洲绒毛猴或蜘蛛猴的大脑，而不像黑猩猩或大猩猩的大脑。
