Restriction fragment length polymorphisms (RFLPs) are variations in DNA sequences that can be detected by digestion with restriction enzymes. RFLPs are used to study variation and evolution within populations. This study focused on a specific PvFLP occurring within the human ACTG2 (formerly ACTA3) gene. ACTG2 encodes a γ-actin specifically expressed in mammalian enteric muscle. The RFLP occurs within the first intron and, while not a linkage marker for any genetic condition, has implications as a marker in human evolution. Humans normally have two copies of each chromosome. Each chromosome contributes one allele towards the pair examined using Mendelian genetics. An earlier study of the RFLP, conducted among Japanese and Caucasian populations, published the finding that the RFLP allele occurred twenty-one times more frequently in Caucasian populations. This study expanded analysis on this RFLP by surveying allelic frequencies in African Americans. Two hypotheses to explain earlier allelic results were tested: (1) the RFLP occurred after human migration from Africa, and some unknown selection pressure existed that maintained the RFLP among Caucasians, or (2) the original, small Caucasian sample size accounted for the observed result. In the African Americans sample, as well as an expanded Caucasian sample, both forms of the RFLP were distributed evenly after random sampling analysis. The results suggest a sampling error as the most likely explanation for earlier studies conducted on Caucasians.