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NSF Press Release

 


NSF PR 02-92 - November 14, 2002

Note About Images

Photo 1

graph showing how E. coli bacteria in a laboratory evolved over time; caption is below

graph showing how E. coli bacteria in a laboratory evolved over time; caption is below

The two images show how E. coli bacteria in a laboratory evolved over time to metabolize and grow at a rate predicted by a computer simulation. The bottom left axis represents the amount of oxygen that the bacteria consumed, the bottom right axis represents the amount of glycerol (the food) the bacteria consumed, and the vertical axis represents the rate at which the bacteria grew.
The colored surfaces are called "phenotype phase planes." They graphically represent the researchers' in silico (computer) prediction for the possible ways in which the bacteria could grow under specific environmental conditions. The red shading represents faster growth conditions, the green represents slower growth.
The red line is the "line of optimality," the optimal growth rate predicted by the researchers' computer model. Region 1 represents a phase where growth is not optimal, Region 2 represents a phase where the bacteria consume too much food and therefore have to secrete some as byproducts of metabolism.
The white dots are measurements of how several E. coli specimens were metabolizing food, and how fast they were growing when the researchers tested them. After 40 days (700 generations), the bacteria evolved to metabolize as predicted by the researchers' in silico model (all specimens cluster along the line of optimality).
Photo Credit: Images courtesy of the Genetic Circuits Research Group (Rafael U. Ibarra, Jeremy S. Edwards, and Bernhard O. Palsson).

Return to Press Release NSF PR 02-92 - November 14, 2002

 

 
 
     
 

 
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