Conversation so far:
What type of work was Richard Lewontin involved in?
Richard Lewontin has worked in both theoretical and experimental population genetics.
What else did Richard Lewontin accomplish?
Richard Lewontin was the first person to do a computer simulation of the behavior of a single gene locus (previous simulation work having been of models with multiple loci).
What else was Richard Lewontin the first to do besides being the first person to do a computer simulation of the behavior of a single gene locus?
In 1960 Sergio Agüero and Ken-Ichi Kojima were the first population geneticists to give the equations for change of haplotype frequencies with interacting natural selection at two loci.
What resulted from Richard Lewontin's discoveries in population genetics?
Sergio Agüero and Ken-Ichi Kojima's equations for change of haplotype frequencies with interacting natural selection at two loci set off a wave of theoretical work on two-locus selection.

Question: What happened to him next in his career?
Self-contained rewrite: What happened to Richard Lewontin next in his career after the equations for change of haplotype frequences with interacting natural selection at two loci?