Is the remarkable diversity in the behavior of insects reflected in the organization of their nervous systems? The ventral nerve cords (VNCs) have been described from over 300 insect species covering all the major orders. Interpreting these data in the context of phylogenetic relationships reveals remarkable diversity. The presumed ancestral VNC structure is rarely observed; instead the VNCs of most insects show extensive modification and substantial convergence. Modifications include shifts in neuromere positions, their fusion to form composite ganglia, and, potentially, their separation to revert to individual ganglia. These changes appear to be facilitated by the developmental and functional modularity of the VNC, a neuromere for each body segment. The differences in VNC structure emphasize trade-offs between behavioral requirements and the costs incurred while maintaining the nervous system and signaling between its various parts. The diversity in structure also shows that nervous systems may undergo dramatic morphological changes during evolution.

中文翻译：

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昆虫腹侧神经索的多样性和进化。

昆虫行为的显着多样性是否反映在其神经系统的组织中？已经描述了涵盖所有主要订单的300多种昆虫的腹神经索（VNC）。在系统发育关系的背景下解释这些数据揭示了显着的多样性。几乎没有观察到祖先的VNC结构。相反，大多数昆虫的VNC表现出广泛的修饰和实质的收敛。修饰包括神经绒毛位置的改变，它们的融合以形成复合神经节，以及可能的分离以恢复为单个神经节。VNC的发展和功能模块性似乎促进了这些变化，VNC是每个身体节段的神经纤维。VNC结构的差异强调了行为要求与维护神经系统及其各个部分之间的信号传递所产生的成本之间的权衡。结构的多样性还表明，神经系统在进化过程中可能会发生剧烈的形态变化。