Epigenetics is the study of how the expression or suppression of particular genes by chemical modifications affects an organism's physical characteristics, development, and behavior; if that sounds vague or perhaps even Lamarckian, your confusion is understandable. It is believed that epigenetic processes play a significant role in many diseases and are also involved in longevity and aging. Extrapolating epigenetics, some even go so far as to blame a student's college academic performance on diet - the father's, before conception. You really can blame everything on your parents.
But in simpler creatures with complex-seeming caste systems, epigenetics is more rigorous. A group found that epigenetic regulation is key to distinguishing one caste, the "majors", as brawny Amazons of the carpenter ant colony, compared to the "minors", their smaller, brainier sisters. These two castes have the same genes, but strikingly distinct behaviors and shape.
Ants, as well as termites and some bees and wasps, are eusocial species that organize themselves into rigid caste-based societies, or colonies, in which only one queen and a small contingent of male ants are usually fertile and reproduce. The rest of a colony is composed of functionally sterile females that are divided into worker castes that perform specialized roles such as foragers, soldiers, and caretakers. In Camponotus floridanus, there are two worker castes that are physically and behaviorally different, yet genetically very similar.
Lead author Daniel F. Simola, PhD, a postdoctoral researcher at Penn, explains that "the major is also called a soldier, and it has a much larger head, so the force of its mandibles can break larger prey. It