title: The multiple directions of evolutionary change.
abstract: The theory of Punctuated Equilibria challenges the neo-Darwinian tenet that evolution is a uniform process. Recently, an article by Hunt has found that directional change during the evolution of a lineage is relatively small (occurring only in 5% of 250 analyzed traits). Of those traits that were shown to follow a trend, size was more likely to show gradual changes, whereas shape changes were more random. Here, we provide a short view of the nature of evolutionary trends, showing that directional change within lineages and among clades provides valuable evolutionary information about the processes involved in their generation.
authors.affiliation: Theoretical Biology Research Group, Institute Cavanilles for Biodiversity and Evolutionary Biology, University of Valencia, Spain. diego.rasskin@uv.es
authors.forename: Diego
authors.initials: D
authors.lastname: Rasskin-Gutman
authors.forename: Borja
authors.initials: B
authors.lastname: Esteve-Altava
mesh_terms: D000818:Animals; D005075:Biological Evolution; D049628:Body Size; D040961:Genetic Drift; D008957:Models, Genetic; D009024:Morphogenesis; D011156:Population Density; D012641:Selection, Genetic