The development of aptamers on custom synthesized DNA microarrays, which has been
demonstrated in recent publications, can facilitate detailed analyses of sequence and fitness
relationships. Here we use the technique to observe the paths taken through sequence-fitness
space by three different evolutionary regimes: asexual reproduction, recombination and
model-based evolution. The different evolutionary runs are made on the same array chip in
triplicate, each one starting from a small population initialized independently at random.
When evolving to a common target protein, glucose-6-phosphate dehydrogenase (G6PD),
these nine distinct evolutionary runs are observed to develop aptamers with high affinity and to
converge on the same motif not present in any of the starting populations. Regime specific
differences in the evolutions, such as speed of convergence, could also be observed