title: Strength in numbers: High phenotypic variance in early Cambrian trilobites and its evolutionary implications.
abstract: Analysis of the degree of intraspecific morphological polymorphism during the evolutionary history of trilobites using an informatic approach(1) provides striking evidence of a long-suspected but previously unsubstantiated pattern: degrees of polymorphism are markedly higher in phylogenetically basal, stratigraphically early species. This unequivocal pattern prompts further exploration of the relationship between microevolutionary variance and macroevolutionary history. It demonstrates that the 'traditional' fossil record of skeletonized organisms can provide unique insight into questions of major evolutionary interest.
authors.affiliation: Department of Earth Sciences, University of California, Riverside, CA 92521, USA. nigel.hughes@ucr.edu
authors.forename: Nigel C
authors.initials: NC
authors.lastname: Hughes
mesh_terms: D000818:Animals; D001181:Arthropods / Q000033:anatomy & histology* / Q000145:classification / Q000235:genetics; D005075:Biological Evolution; D005580:Fossils; D049810:Genetic Speciation; D014644:Genetic Variation; D010163:Paleontology; D010802:Phylogeny; D011110:Polymorphism, Genetic; D013045:Species Specificity; D013995:Time