GONZALEZ paula Natalia
capítulos de libros
Canalization: A central but controversial concept in Evo-Devo
Evolutionary Developmental Biology A Reference Guide
Año: 2018; p. 1 - 16
Canalization refers to, in a broader sense, the production of consistent phenotypic traits in the face of genetic and environmental variation. It is a key concept for evolutionary developmental biology because it is one of the properties of developmental systems that modulates the expression of phenotypic variation, influencing the potential for evolutionary change (i.e., evolvability). Although the relevance of canalization is widely accepted, many topics around this concept are still a matter of debate. In this chapter, we first summarize the views about canalization from developmental and genetic population biologists and then discuss the mechanisms, origin, and evolutionary role of canalization. Mechanisms proposed to explain how canalization is achieved range from single molecular factors to complex interactions in the developmental-genetic architecture. Contrasting views also characterize explanations about the origin of canalization, with positions that favor an adaptive origin derived from selective forces and others that consider canalization as an emergent product of developmental processes. Independently of its origin, the role of canalization in the evolution of phenotypic traits is also controversial. Since canalized traits reduce the range of phenotypic outputs, canalization could be expected to reduce evolvability. However, it has been proposed that canalization allows the accumulation of new cryptic mutations that are maintained within populations and can be expressed in certain evolutionary contexts. In sum, we provide an updateddiscussion on this elusive but key concept, attempting to review contrasting andcomplementary positions.