Departments of Psychology and Biology, University of Washington, Seattle, WA 98195, USA.
Proc Natl Acad Sci U S A. 2011 Apr 26;108(17):7107-12. doi: 10.1073/pnas.1017566108. Epub 2011 Apr 11.
We compared species mean data on the size of functionally distinct brain regions to test the relative rates at which investment in higher-order cognitive processing (mushroom body calyces) versus peripheral sensory processing (optic and antennal lobes) increased with increasing brain size. Subjects were eusocial paper wasps from queen and worker castes of 10 species from different genera. Relative investment in central processing tissue increased with brain size at a higher rate than peripheral structure investment, demonstrating that tissue devoted to higher-order cognitive processing is more constrained by brain size. This pattern held for raw data and for phylogenetically independent contrasts. These findings suggest that there is a minimum necessary investment in peripheral sensory processing brain tissue, with little to gain from additional investment. In contrast, increased brain size provides opportunities to invest in additional higher-order cognitive processing tissue. Reproductive castes differed within species in brain tissue investment, with higher central-to-peripheral brain tissue ratios in queens than in workers. Coupled with previous findings that paper wasp queen, but not worker, brain architecture corresponds to ecological and social variation, queen brain evolution appears to be most strongly shaped by cognitive demands, such as social interactions. These evolutionary patterns of neural investment echo findings in other animal lineages and have important implications, given that a greater investment in higher-order processing has been shown to increase the prevalence of complex and flexible behaviors across the animal kingdom.
我们比较了不同物种在功能上不同的大脑区域的物种平均值数据，以测试在更高阶认知处理（蘑菇体的腹片）和外围感觉处理（视叶和触角叶）方面的投资相对于大脑大小的增加而增加的相对速度。研究对象是来自 10 个不同属的 10 个种的蜂王和工蜂的社会性纸巢蜂。与外围结构投资相比，中央处理组织的相对投资随大脑大小的增加而以更高的速度增加，这表明用于更高阶认知处理的组织受到大脑大小的更严格限制。这种模式适用于原始数据和系统发育独立对比。这些发现表明，外围感觉处理脑组织存在最小必要的投资，而额外投资收益甚微。相比之下，大脑大小的增加为额外的高阶认知处理组织提供了投资机会。在物种内，生殖巢具有不同的脑组织投资，蜂王的中央-外围脑组织比率高于工蜂。结合先前的发现，即纸巢蜂的蜂王而非工蜂的大脑结构与生态和社会变化相对应，蜂王大脑的进化似乎主要受到认知需求的影响，例如社会互动。这些神经投资的进化模式与其他动物谱系中的发现相呼应，并且具有重要意义，因为更高阶处理的更大投资已被证明可以增加整个动物王国中复杂和灵活行为的流行度。
