In a series of experiments, a team of biologists at the University of California, San Diego studied the structure of growing colonies comprised of two species of rod-shaped bacteria, Escherichia coli and Acinetobacter baylyi; the researchers were surprised to see that the highly-motile Acinetobacter baylyi accelerated the spread of the slow Escherichia coli and that the structure of the expanding two-species colony became highly heterogeneous and...
