Neurobiology Unit, Scripps Institution of Oceanography and Department of Neurosciences, School of Medicine, University of California, San Diego, La Jolla, California 92093-0201.
Integr Comp Biol. 2002 Aug;42(4):743-56. doi: 10.1093/icb/42.4.743.
Four major questions can be asked about vertebrate brain evolution: 1) What major changes have occurred in neural organization and function? 2) When did these changes occur? 3) By what mechanisms did these changes occur? 4) Why did these changes occur? Comparative neurobiologists have been very successful in recognizing major changes in brain structure. They have also made progress in understanding the functional significance of these changes, although this understanding is primarily limited to sensory centers, rather than integrative or motor centers, because of the relative ease of manipulating the relevant stimuli. Although neuropaleontology continues to provide important insights into when changes occurred, this approach is generally limited to recognizing variation in overall brain size, and sometimes brain regions, as interpreted from the surface of an endocranial cast. In recent years, most new information regarding when neural changes occurred has been based on cladistical analysis of neural features in extant taxa. Historically, neurobiologists have made little progress in understanding how and why brains evolve. The emerging field of evolutionary developmental biology appears to be the most promising approach for revealing how changes in development and its processes produce neural changes, including the emergence of novel features. Why neural changes have occurred is the most difficult question and one that has been the most ignored, in large part because its investigation requires a broad interdisciplinary approach involving both behavior and ecology.
关于脊椎动物脑进化，可以提出四个主要问题：1）神经组织和功能发生了哪些重大变化？2）这些变化发生在何时？3）这些变化是通过什么机制发生的？4）这些变化为什么会发生？比较神经生物学家非常成功地识别了脑结构的重大变化。他们也在理解这些变化的功能意义方面取得了进展，尽管这种理解主要限于感觉中枢，而不是整合或运动中枢，因为操纵相关刺激相对容易。尽管神经古生物学继续提供有关变化发生时间的重要见解，但这种方法通常仅限于从内颅铸型的表面识别整体大脑大小的变化，有时也限于识别大脑区域的变化。近年来，关于神经变化发生时间的大多数新信息都是基于现存分类群的神经特征的分支分析得出的。从历史上看，神经生物学家在理解大脑如何以及为何进化方面几乎没有取得进展。新兴的进化发育生物学领域似乎是揭示发育及其过程如何产生神经变化（包括新特征的出现）的最有前途的方法。为什么神经变化会发生是最困难的问题，也是最被忽视的问题，部分原因是它的研究需要广泛的跨学科方法，涉及行为和生态学。
