首页 | 本学科首页   官方微博 | 高级检索  
   检索      


Placental invasiveness and brain-body allometry in eutherian mammals
Authors:Elliot M G  Crespi B J
Institution:Behavioural Ecology Research Group, Simon Fraser University, Burnaby, BC, Canada. micke@sfu.ca
Abstract:Brain growth is a key trait in the evolution of mammalian life history. Brain development should be mediated by placentation, which determines patterns of resource transfer from mothers to fetal offspring. Eutherian placentation varies in the extent to which a maternal barrier separates fetal tissues from maternal blood. We demonstrate here that more invasive forms of placentation are associated with substantially steeper brain-body allometry, faster prenatal brain growth and slower prenatal body growth. On the basis of the physiological literature we suggest a simple mechanism for these differences: in species with invasive placentation, where the placenta is bathed directly in maternal blood, fatty acids essential for brain development can be readily extracted by the fetus, but in species with less invasive placentation they must be synthesized by the fetus. Hence, with regard to brain-body allometry and prenatal growth patterns, eutherian mammals are structured into distinct groups differing in placental invasiveness.
Keywords:brain size  encephalization  Eutheria  evolution  fatty acids  fetal nutrition  life history  placentation  pregnancy
本文献已被 PubMed 等数据库收录!
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号