PT - JOURNAL ARTICLE AU - Caroline B. Turner AU - Brian D. Wade AU - Justin R. Meyer AU - Richard E. Lenski TI - Evolution of organismal stoichiometry in a 50,000-generation experiment with <em>Escherichia coli</em> AID - 10.1101/021360 DP - 2015 Jan 01 TA - bioRxiv PG - 021360 4099 - http://biorxiv.org/content/early/2015/06/29/021360.short 4100 - http://biorxiv.org/content/early/2015/06/29/021360.full AB - Organismal stoichiometry refers to the relative proportion of chemical elements in the biomass of organisms, and it can have important effects on ecological interactions from population to ecosystem scales. Although stoichiometry has been studied extensively from an ecological perspective, little is known about rates and directions of evolutionary changes in elemental composition in response to nutrient limitation. We measured carbon, nitrogen, and phosphorus content of Escherichia coli evolved under controlled carbon-limited conditions for 50,000 generations. The bacteria evolved higher relative nitrogen and phosphorus content, consistent with selection for increased use of the more abundant elements. Total carbon assimilated also increased, indicating more efficient use of the limiting element. Altogether, our study shows that stoichiometry evolved over a relatively short time-period, and that it did so in a predictable direction given the carbon-limiting environment.