突變穩(wěn)健性（Mutational robustness）在演化中所起作用一直是一個存在很對爭論和爭議的問題,。一方面，它似乎通過在發(fā)生環(huán)境變化時使得一種新的表現(xiàn)型不易形成來妨礙適應(yīng),；另一方面,，它似乎又能幫助一種生物使其表現(xiàn)型在可能不利的突變面前得到緩沖。一種生物怎樣解決這種矛盾,、從而同時具有穩(wěn)健性和適應(yīng)性呢,？
現(xiàn)在，一個定量種群遺傳學(xué)模型對這一問題給出了一個可能的解答,。該模型表明,，突變穩(wěn)健性技能妨礙適應(yīng)，又能幫助適應(yīng),，到底如何則取決于種群大小,、突變速度和適應(yīng)性環(huán)境的結(jié)構(gòu)。（生物谷Bioon.com）
生物谷推薦原始出處：
Nature 463, 353-355 (21 January 2010) | doi:10.1038/nature08694
Mutational robustness can facilitate adaptation
Jeremy A. Draghi1, Todd L. Parsons1, Günter P. Wagner3 & Joshua B. Plotkin1,2
1 Department of Biology,
2 Program in Applied Mathematics and Computational Science, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
3 Department of Ecology and Evolutionary Biology, Yale University, New Haven, Connecticut 06520, USA
4 Correspondence to: Joshua B. Plotkin1,2 Correspondence and requests for materials should be addressed to J.B.P.
Robustness seems to be the opposite of evolvability. If phenotypes are robust against mutation, we might expect that a population will have difficulty adapting to an environmental change, as several studies have suggested1, 2, 3, 4. However, other studies contend that robust organisms are more adaptable5, 6, 7, 8. A quantitative understanding of the relationship between robustness and evolvability will help resolve these conflicting reports and will clarify outstanding problems in molecular and experimental evolution, evolutionary developmental biology and protein engineering. Here we demonstrate, using a general population genetics model, that mutational robustness can either impede or facilitate adaptation, depending on the population size, the mutation rate and the structure of the fitness landscape. In particular, neutral diversity in a robust population can accelerate adaptation as long as the number of phenotypes accessible to an individual by mutation is smaller than the total number of phenotypes in the fitness landscape. These results provide a quantitative resolution to a significant ambiguity in evolutionary theory.
