A geneticist was an expert in genetics. Doctor Arik Soong was a well-known geneticist. (ENT: "Borderland") Geneticists on Moab IV were able to screen out any congenital health problems before a child was conceived. (TNG: "The Masterpiece Society " ) The Bajoran Dekon Elig was a geneticist. (DS9: "Babel") Some geneticists were of the opinion that Klingons developed a third lung in order to increase their stamina while fighting. (VOY: "Lineage")