Blood ties fuel cooperation among species, not survival instinct
(PHYSorg.com Biology)

Cooperative breeding, when adults in a group team up to care for offspring, is not a survival strategy for animals living in extreme environments. It is instead a natural result of monogamous relationships reinforcing stronger genetic bonds in family groups. Siblings with full biological ties are more likely than others to stay with their family and help day to day, a new Oxford University study has found.