Department of Systems Medicine, University of Rome Tor Vergata Rome, Italy ; Centre of Space Bio-Medicine, University of Rome Tor Vergata Rome, Italy ; Laboratory of Neuromotor Physiology, IRCCS Santa Lucia Foundation Rome, Italy.
Front Comput Neurosci. 2013 May 17;7:61. doi: 10.3389/fncom.2013.00061. eCollection 2013.
The identification of biological modules at the systems level often follows top-down decomposition of a task goal, or bottom-up decomposition of multidimensional data arrays into basic elements or patterns representing shared features. These approaches traditionally have been applied to mature, fully developed systems. Here we review some results from two other perspectives on modularity, namely the developmental and evolutionary perspective. There is growing evidence that modular units of development were highly preserved and recombined during evolution. We first consider a few examples of modules well identifiable from morphology. Next we consider the more difficult issue of identifying functional developmental modules. We dwell especially on modular control of locomotion to argue that the building blocks used to construct different locomotor behaviors are similar across several animal species, presumably related to ancestral neural networks of command. A recurrent theme from comparative studies is that the developmental addition of new premotor modules underlies the postnatal acquisition and refinement of several different motor behaviors in vertebrates.
在系统水平上识别生物模块通常遵循自上而下的任务目标分解，或者将多维数据数组分解为代表共享特征的基本元素或模式的自下而上的分解。这些方法传统上应用于成熟的、完全开发的系统。在这里，我们从另外两个角度，即发展和进化的角度，来回顾一些关于模块性的结果。越来越多的证据表明，在进化过程中，发育的模块单元高度保存并重新组合。我们首先考虑几个从形态学上可很好识别的模块的例子。接下来，我们考虑更困难的识别功能发育模块的问题。我们特别关注运动的模块化控制，以论证用于构建不同运动行为的构建块在几个动物物种中是相似的，可能与命令的祖先神经网络有关。比较研究的一个反复出现的主题是，新的前运动模块的发育增加是脊椎动物几种不同运动行为的出生后获得和细化的基础。
