Primate brains, the 鈥榠sland rule鈥?and the evolution of Homo floresiensis

详细信息    查看全文

• 作者：Stephen H. Montgomery
• 关键词：Brain size ; Dwarfism ; Allometry ; Body mass ; Insularity
• 刊名：Journal of Human Evolution
• 出版年：December, 2013
• 年：2013
• 卷：65
• 期：6
• 页码：750-760
• 全文大小：637 K

文摘

The taxonomic status of the small bodied hominin, Homo floresiensis, remains controversial. One contentious aspect of the debate concerns the small brain size estimated for specimen LB1 (Liang Bua 1). Based on intraspecific mammalian allometric relationships between brain and body size, it has been argued that the brain of LB1 is too small for its body mass and is therefore likely to be pathological. The relevance and general applicability of these scaling rules has, however, been challenged, and it is not known whether highly encephalized primates adapt to insular habitats in a consistent manner. Here, an analysis of brain and body size evolution in seven extant insular primates reveals that although insular primates follow the 鈥榠sland rule鈥? having consistently reduced body masses compared with their mainland relatives, neither brain mass nor relative brain size follow similar patterns, contrary to expectations that energetic constraints will favour decreased relative brain size. Brain:body scaling relationships previously used to assess the plausibility of dwarfism in H.聽floresiensis tend to underestimate body masses of insular primates. In contrast, under a number of phylogenetic scenarios, the evolution of brain and body mass in H.聽floresiensis is consistent with patterns observed in other insular primates.