Department of Ecology and Evolutionary Biology, National Institute for Mathematical and Biological Synthesis, University of Tennessee, Knoxville, Tennessee, United States of America.
PLoS Comput Biol. 2010 Jun 10;6(6):e1000805. doi: 10.1371/journal.pcbi.1000805.
A crucial step in several major evolutionary transitions is the division of labor between components of the emerging higher-level evolutionary unit. Examples include the separation of germ and soma in simple multicellular organisms, appearance of multiple cell types and organs in more complex organisms, and emergence of casts in eusocial insects. How the division of labor was achieved in the face of selfishness of lower-level units is controversial. I present a simple mathematical model describing the evolutionary emergence of the division of labor via developmental plasticity starting with a colony of undifferentiated cells and ending with completely differentiated multicellular organisms. I explore how the plausibility and the dynamics of the division of labor depend on its fitness advantage, mutation rate, costs of developmental plasticity, and the colony size. The model shows that the transition to differentiated multicellularity, which has happened many times in the history of life, can be achieved relatively easily. My approach is expandable in a number of directions including the emergence of multiple cell types, complex organs, or casts of eusocial insects.
在几个主要进化转变中，至关重要的一步是新兴的更高层次进化单位的各个组成部分之间的分工。例如，简单多细胞生物中生殖细胞和体细胞的分离、更复杂的生物体中多种细胞类型和器官的出现，以及真社会性昆虫中出现的职虫。在面对低层次单位的自私行为时，如何实现分工是有争议的。我提出了一个简单的数学模型，描述了从一个未分化的细胞群开始，最终形成完全分化的多细胞生物，通过发育可塑性来实现分工的进化出现。我探讨了分工的可能性和动态如何取决于其适应优势、突变率、发育可塑性成本以及殖民地规模。该模型表明，向已经发生在生命历史上很多次的分化多细胞性的转变相对容易实现。我的方法可以在许多方面扩展，包括多种细胞类型、复杂器官或真社会性昆虫职虫的出现。
