Department of Biology, Indiana University, 915 East Third Street, Myers Hall 150, Bloomington, IN 47405-7107, USA.
Philos Trans R Soc Lond B Biol Sci. 2010 Feb 27;365(1540):593-603. doi: 10.1098/rstb.2009.0263.
Phenotypic plasticity in general and polyphenic development in particular are thought to play important roles in organismal diversification and evolutionary innovation. Focusing on the evolutionary developmental biology of insects, and specifically that of horned beetles, I explore the avenues by which phenotypic plasticity and polyphenic development have mediated the origins of novelty and diversity. Specifically, I argue that phenotypic plasticity generates novel targets for evolutionary processes to act on, as well as brings about trade-offs during development and evolution, thereby diversifying evolutionary trajectories available to natural populations. Lastly, I examine the notion that in those cases in which phenotypic plasticity is underlain by modularity in gene expression, it results in a fundamental trade-off between degree of plasticity and mutation accumulation. On one hand, this trade-off limits the extent of plasticity that can be accommodated by modularity of gene expression. On the other hand, it causes genes whose expression is specific to rare environments to accumulate greater variation within species, providing the opportunity for faster divergence and diversification between species, compared with genes expressed across environments. Phenotypic plasticity therefore contributes to organismal diversification on a variety of levels of biological organization, thereby facilitating the evolution of novel traits, new species and complex life cycles.
表型可塑性，尤其是多态发育，被认为在生物多样性和进化创新中发挥着重要作用。本研究聚焦昆虫进化发育生物学，特别是角蝉类，探讨了表型可塑性和多态发育在新异性和多样性起源中的作用途径。具体而言，我认为表型可塑性为进化过程提供了新的作用靶点，并在发育和进化过程中带来了权衡，从而使自然种群可用的进化轨迹多样化。最后，我考察了这样一种观点，即在表型可塑性由基因表达的模块性所决定的情况下，它会导致可塑性程度与突变积累之间的基本权衡。一方面，这种权衡限制了由基因表达模块性所允许的可塑性程度。另一方面，它使那些特定于稀有环境的表达的基因在物种内积累更多的变异，与在环境中表达的基因相比，为物种间更快的分化和多样化提供了机会。因此，表型可塑性在生物组织的各个层次上促进了生物多样性，从而促进了新性状、新物种和复杂生命周期的进化。
