Presentation Type

Poster

Faculty Mentor’s Full Name

Frank Rosenzweig

Faculty Mentor’s Department

Biological Sciences

Abstract

In simple, constant environments containing one food source, theory and intuition suggest that only one type of organism should prevail. However, a lab population of E. coli founded by a single clone quickly evolved into a community of interacting cell types. Bacteria were cultured under glucose limitation, selecting for its avid consumption. One strain, A, best scavenges glucose but does so wastefully, providing strains B and C with by-products that support their growth. Thus, multiple interacting cell types may better use limited resources than one. I therefore posed the questions: How much more fit is each strain relative to the common ancestor, and does cohabitation provide fitness advantages? We competed strains of P, A, B, and C expressing green fluorescent proteins, and quantified their relative numbers in a simple, controlled environment. Fitnesses ranked as (A+B+C)>(A=B)>A>B>C, support the view that a cooperating community can evolve outperform a single individual. Quantifying relative fitness in experimentally evolved communities reveals that the sum may be greater than its parts, providing a clue as to how biocomplexity arises, even in simple systems governed by Darwinian principles.

Category

Life Sciences

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Apr 15th, 11:00 AM Apr 15th, 12:00 PM

Better than Before and Better Together

In simple, constant environments containing one food source, theory and intuition suggest that only one type of organism should prevail. However, a lab population of E. coli founded by a single clone quickly evolved into a community of interacting cell types. Bacteria were cultured under glucose limitation, selecting for its avid consumption. One strain, A, best scavenges glucose but does so wastefully, providing strains B and C with by-products that support their growth. Thus, multiple interacting cell types may better use limited resources than one. I therefore posed the questions: How much more fit is each strain relative to the common ancestor, and does cohabitation provide fitness advantages? We competed strains of P, A, B, and C expressing green fluorescent proteins, and quantified their relative numbers in a simple, controlled environment. Fitnesses ranked as (A+B+C)>(A=B)>A>B>C, support the view that a cooperating community can evolve outperform a single individual. Quantifying relative fitness in experimentally evolved communities reveals that the sum may be greater than its parts, providing a clue as to how biocomplexity arises, even in simple systems governed by Darwinian principles.