This episode's headline: Human Genetic Engineering. The guests include ALEX CAPRON, President's Commission on Medical Ethics; Dr. BERNARD DAVIS, Harvard University; Rep. ALBERT GORE, Jr., Democrat, Tennessee; In Boston (Facilities: WGBH-TV): SHELDON KRIMSKY, Tufts University. Byline: In New York: ROBERT MacNEIL, Executive Editor; JIM LEHRER, Associate Editor; LEWIS SILVERMAN, Producer; MAURA LERNER, Reporter