title: Evolution: opportunity versus innovation.
authors.forename: Paul H
authors.initials: PH
authors.lastname: Harvey
authors.forename: Andy
authors.initials: A
authors.lastname: Purvis
mesh_terms: D000222:Adaptation, Physiological; D000818:Animals; D005075:Biological Evolution; D004463:Ecology; D017753:Ecosystem; D005260:Female; D008297:Male; D008954:Models, Biological; D010802:Phylogeny; D012641:Selection, Genetic; D012727:Sex Characteristics; D020308:Songbirds / Q000033:anatomy & histology / Q000145:classification* / Q000502:physiology*; D013045:Species Specificity