. . "After the baby was born, he could feel more sure he was the dad if the baby looked like him (???He has your feet, Honey!???), but often these early resemblances are at least partially creative imaginations.In 1901 biologist Karl Landsteiner distinguished between three types of blood ??? groups A, B, and O. A fourth group ??? AB ??? was discovered a year later by another research team." . .