Study linking DNA to behavior is telling

There is an ongoing argument over whether homosexual or heterosexual behavior is genetically determined or is a matter of choice. Recent scientific findings have shed light on this discussion. The science called epigenetics studies how reactions switch genes on and off at appropriate times and in appropriate locations to regulate an organism’s proper development. For example, switching on fingernail genes to grow on toes would be entirely inappropriate, but appropriate on fingers. Until recently, however, epigenetics has never been shown to determine social behavior. That has changed.
Very recently scientists have demonstrated that a single, tiny difference in a bee’s DNA determines whether it will develop into a nurse, the “stay-at-home moms” of the bee world, feeding and cleaning the hive’s larvae, or will become a forager that adventurously leaves the hive in search of new food sources or hive locations. Even more remarkably, the researchers were able to reverse this behavior, turning nurses into foragers and vice versa, by reversing that one small change in the bee’s DNA. This is the first time that a small and reversible change in an organism’s DNA has been shown to influence its social behavior.
Obviously, bees and humans aren’t the same, but this important finding sheds light on a key aspect of how DNA works and demonstrates that the social behavior of bees, at least, is determined by tiny but important differences in their DNA. This indicates that the tendency to develop with male or female tendencies is also likely to be genetically determined in human beings and is probably not a simple matter of choice. Human epigenetic studies investigating this important question will surely follow.
Frank J. Dinan
Chemistry Professor, Emeritus,
Canisius College