During his time in Iran, James E. Bowman conducted research on favism, a genetic disorder characterized by a deficiency of glucose-6-phosphate dehydrogenase (G6PD)(Bowman and Ronaghy 1967). Bowman collected blood samples from Muslim men in Iran, determining phenotype and allele frequencies. He demonstrated how genetic variations in hemoglobin, G6PD, phosphoglycerate dehydrogenase, and adenylate kinase were present in the Muslim populations (Bowman and Ronaghy 1967). Dr. Bowman was also one of the first geneticists to use starch-gel electrophoresis to study human samples, an important step forward in modern genetics practice (Suarez-Diaz 2017). His methods led him to the discovery of a new allele variant, 6-GDP-B, in the Lacandon Indigenous population of Mexico and identify more allele bands through electrophoresis, furthering research on the heredity of G6PD in diverse populations internationally (Suarez-Diaz 2017). 

The results of his work demonstrated differences in allele frequencies within different populations, corresponding to different variations in proteins and enzymes (Bowman and Ronaghy 1967). The results from his research were important in understanding genetic differences among populations to improve health research and understand how people respond to certain diseases, medications, or potentially environmental factors. Bowman's work on favism took him around the world, effectively improving the understanding of favism and how it is prevalent among different racial populations. This research is related to his concerns about the exploitation of genetic variation among populations and how this provides a foundation for eugenics.

Bowman and his colleagues wanted to understand how an organism prevents the harmful effects of somatic mutations. They began by looking at hemoglobin and hypothesized that the primary structure undergoes adjustment which prevents mutations from causing harm. Certain residues are more likely to cause harm than others because they differ from a terminator codon by a single base and are classified as “termutable” amino acids. Calculations are used to quantify the mutability of amino acids. Each codon can undergo nine different single base changes. Since leucine has six codons, it can undergo 54 equally likely single base changes, three of which result in a terminator. The mutability of leucine is 3/54 whereas the mutability of tryptophan is 2/9, so tryptophan is four times as mutable as leucine. By weighing the residues of hemoglobin chains, the alpha chain was discovered to be the least mutable. In addition, longer polypeptide chains are more susceptible to the destruction of function due to there being more termutable residues causing terminator mutations. The findings of the study conclude that natural selection influences which codons are used to code for amino acids. When codons for a certain amino acid are more termutable than others, they will be used less often (Shaw et al. 1977).