title: Evolutionary trade-offs, Pareto optimality, and the geometry of phenotype space.
abstract: Biological systems that perform multiple tasks face a fundamental trade-off: A given phenotype cannot be optimal at all tasks. Here we ask how trade-offs affect the range of phenotypes found in nature. Using the Pareto front concept from economics and engineering, we find that best-trade-off phenotypes are weighted averages of archetypes--phenotypes specialized for single tasks. For two tasks, phenotypes fall on the line connecting the two archetypes, which could explain linear trait correlations, allometric relationships, as well as bacterial gene-expression patterns. For three tasks, phenotypes fall within a triangle in phenotype space, whose vertices are the archetypes, as evident in morphological studies, including on Darwin's finches. Tasks can be inferred from measured phenotypes based on the behavior of organisms nearest the archetypes.
authors.affiliation: Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot, Israel.
authors.forename: O
authors.initials: O
authors.lastname: Shoval
authors.forename: H
authors.initials: H
authors.lastname: Sheftel
authors.forename: G
authors.initials: G
authors.lastname: Shinar
authors.forename: Y
authors.initials: Y
authors.lastname: Hart
authors.forename: O
authors.initials: O
authors.lastname: Ramote
authors.forename: A
authors.initials: A
authors.lastname: Mayo
authors.forename: E
authors.initials: E
authors.lastname: Dekel
authors.forename: K
authors.initials: K
authors.lastname: Kavanagh
authors.forename: U
authors.initials: U
authors.lastname: Alon
mesh_terms: D000818:Animals; D001502:Beak / Q000033:anatomy & histology; D005075:Biological Evolution; D049628:Body Size; D004926:Escherichia coli / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D046369:Finches / Q000033:anatomy & histology; D015870:Gene Expression; D056084:Genetic Fitness; D008954:Models, Biological; D015233:Models, Statistical; D010641:Phenotype; D012641:Selection, Genetic