Farabee demonstrated that
Mendelian genetics operate in man. The founder of genetics,
Gregor Mendel, published the results of his studies on pea plants and heredity in 1865. The work of Mendel was not recognized for its importance until it was rediscovered in 1900. During the intervening 35 years, the "discovery of
chromosomes and their behavior in cell division and
gametogenesis, and intensive study of cell biological variation, and…a conceptual framework for a theory of heredity, development, and evolution" all came about. "The time was ripe for Mendelism" according to Stern. The bulk of his research was regarding a hereditary conditions that primarily afflicts the hands of individuals, entitled Brachydactyly.
Brachydactyly is a dominant genetic trait that is characterized by shortened fingers and shortened stature. Farabee noticed that this trait ran in families. For his dissertation research, Farabee chose a family affected by this trait and followed their
pedigree back five generations. By doing so he showed that the ratio of those with and without brachydactyly followed a pattern explained by Mendel's pattern of inheritance. The children of an abnormal (A) individual, and a normal (N) individual, had a close to fifty percent chance of being abnormal. Farabee stated that an abnormal individual typically would have a genotype of AN, and the family's practice of exogamy meant that their spouse would have a
genotype of NN. By crossing the two, ANxNN, the offspring could be normal or abnormal with an equal chance of either. Because the trait is dominant, if an individual does not carry the trait, they are
homozygous normal and have no risk of passing the trait on to their children, which Farabee also studied in his pedigrees. Farabee also published on the occurrence of recessive traits in humans. While in the South, he met several albino
African-American individuals, and after inquiring into their family background, noticed that the albino trait followed the 3:1 ratio in the second generation that is typical of recessive genotypes. ==Travels in South America==