EVOLUTIONARY RADIATION OF VISUAL AND OLFACTORY BRAIN SYSTEMS IN PRIMATES, BATS AND INSECTIVORES
EVOLUTIONARY RADIATION OF VISUAL AND OLFACTORY BRAIN SYSTEMS IN PRIMATES, BATS AND INSECTIVORES
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DOI：
10.1098/rstb.1995.0076
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发表时间：
1995-06-29
期刊：
影响因子：
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通讯作者：
HARVEY, PH
中科院分区：
文献类型：
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作者：
BARTON, RA;PURVIS, A;HARVEY, PH
当代物种大脑结构差异的生态相关性阐明了大脑如何在特定的选择压力下进化。大多数比较研究的重点都是大脑的总体尺寸相对于身体尺寸，因此忽略了选择对特定神经系统的作用方式。在这里，我们调查的进化辐射的视觉和嗅觉的大脑结构的大小在三个订单的哺乳动物：灵长类动物，蝙蝠和食虫动物。这三种秩序的比较关系既有相似之处，也有不同之处。在去除整体大脑大小的异速生长效应后，每种感觉方式中不同结构的大小在所有三个顺序中呈正相关。然而，视觉和嗅觉结构之间的相关性在灵长类动物中是负的，在食虫动物中是负的但不显著，在蝙蝠中是正的。在灵长类动物和食虫动物中，夜行性谱系往往比昼行性或部分昼行性谱系具有更大的嗅觉结构，而在灵长类动物中，昼行性谱系具有更大的条纹状视觉皮层。因此，灵长类动物视觉和嗅觉之间的明显权衡似乎与夜间和白天形式的分歧有关。然而，视觉和嗅觉结构之间的负相关性，也发现夜间strepsirhines和白天haplorhines分别进行分析时，除了活动时间的生态变量可能是显着的。事实上，食果动物也与饮食有关：食果动物与昼行灵长类的膝状纹状体视觉系统的扩大有关，与夜行灵长类的嗅觉结构的扩大有关，也可能与蝙蝠两者的扩大有关。进一步的生态协会内发现食虫动物：水生谱系有较小的嗅觉结构比非水生同行，和fossorial谱系有较小的视神经比非fossorial形式。我们的结论是，活动的时间，饮食和栖息地发挥了作用，在进化辐射的哺乳动物的感觉系统，但在不同类群的影响。生态学和感觉系统之间的一些联系为大脑整体大小的相关性提供了另一种解释，在过去，这通常被解释为对智力的选择。
How brains have evolved in response to particular selection pressures is illuminated by ecological correlates of differences in brain structure among contemporary species. The focus of most comparative studies has been on the overall size of brains relative to body size, hence ignoring the ways in which selection operates on specific neural systems. Here we investigate evolutionary radiations in the size of visual and olfactory brain structures within three orders of mammals: primates, bats and insectivores. The comparative relationships within these three orders show both similarities and differences. After removal of the allometric effect of overall brain size, the sizes of different structures within each sensory modality are positively correlated in all three orders. Correlations between visual and olfactory structures, however, are negative in primates, negative but non-significant in insectivores, and positive in bats. In both primates and insectivores, nocturnal lineages tend to have larger olfactory structures than do diurnal or partly diurnal lineages, and among the primates diurnal lineages have larger striate visual cortexes. Hence the apparent trade-off between vision and olfaction in primates seems to be related to the divergence of nocturnal and diurnal forms. However, negative correlations between visual and olfactory structures were also found when nocturnal strepsirhines and diurnal haplorhines were analysed separately, suggesting that ecological Variables in addition to activity timing may be significant. Indeed, there were also associations with diet: frugivory was associated with enlargements of the geniculostriate visual system in diurnal primates, enlargements of olfactory structures in nocturnal primates, and possibly enlargements of both in bats. Further ecological associations were found within insectivores: aquatic lineages had smaller olfactory structures than in their non-aquatic counterparts, and fossorial lineages had smaller optic nerves than in non-fossorial forms. We conclude that activity timing, diet and habitat have each played a role in the evolutionary radiation of mammalian sensory systems, but with varying effects in the different taxa. Some of the associations between ecology and sensory systems suggest alternative explanations for correlates of overall brain size, which have in the past commonly been interpreted in terms of selection on intelligence.