TABLE 3.

Dynamics of the evolved pbpA alleles in populations Ara-5 and Ara+1

Generation	No. of clones with pbpA-5/total no.a	No. of clones with pbpA+1/total no.b
500	0/18	0/50
1,000	16/18	0/50
1,500	NDc	15/50
2,000	18/18	44/49

^aFor population Ara-5, PCR products were tested by examining enzymatic restriction with GsuI.

^bFor population Ara+1, the size of the PCR product indicated whether the ancestral or evolved allele was present.

^cND, not determined.