How dose natural selection affect a single gene trait?

How does natural selection affect single-gene traits? Natural selection on single-gene traits can lead to changes in allele frequencies and thus to evolution. Organisms of one color may produce fewer offspring than organisms of other colors.

Explanation:

Organisms of one color may produce fewer offspring than organisms of other colors.

during the process of dna replication, brdu can replace thymidine and incorporate into the newly synthesized dna, cell proliferation thus can be reflected in the extent of brdu incorporation.