Convergence and parallelism reconsidered: what have we learned about the genetics of adaptation?

• Published in: Trends in ecology & evolution (Amsterdam) Vol. 23; no. 1; pp. 26 - 32
• Main Authors: Arendt, Jeff, Reznick, David
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 2008; Elsevier
• Subjects: Adaptation, Biological - genetics; Animal and plant ecology; Animal, plant and microbial ecology; Animals; Biological and medical sciences; Biological Evolution; Fishes - genetics; Fundamental and applied biological sciences. Psychology; Gene Expression Regulation, Developmental; General aspects; Genetics of eukaryotes. Biological and molecular evolution; Genetics, Population; Peromyscus - genetics; Phenotype; Pigmentation - genetics; Polymorphism, Genetic; Quantitative Trait Loci; Receptor, Melanocortin, Type 1 - genetics; Molecular evolution; Genetics; Convergent evolution; Adaptation
• ISSN: 0169-5347; 1872-8383
• DOI: 10.1016/j.tree.2007.09.011

Biologists often distinguish ‘convergent’ from ‘parallel’ evolution. This distinction usually assumes that when a given phenotype evolves, the underlying genetic mechanisms are different in distantly related species (convergent) but similar in closely related species (parallel). However, several examples show that the same phenotype might evolve among populations within a species by changes in different genes. Conversely, similar phenotypes might evolve in distantly related species by changes in the same gene. We thus argue that the distinction between ‘convergent’ and ‘parallel’ evolution is a false dichotomy, at best representing ends of a continuum. We can simplify our vocabulary; all instances of the independent evolution of a given phenotype can be described with a single term – convergent.