Dads rule! Cotton-top tamarin fathers play a major role in raising their offspring and are the main caretakers after birth. Siblings also help to raise youngsters and learn the skills they need to be parents when they are mature. We owe much to these little tamarins. Like humans, cotton-tops can spontaneously develop colon cancer. Since they are the only other primates to suffer from this affliction, many of our treatments for this disease have been developed from research done with cotton-top tamarins.