SINGLE mums are better at raising their kids than two parents—at least in the bird world. Mother zebra finches have to work harder and raise fewer chicks on their own, but they also produce sexier sons who are more likely to get a mate.
The finding shows that family conflict is as important an evolutionary driving force as ecological factors such as predation and food supply. With two parents around, there’s always a conflict of interests, which can have a detrimental effect on the quality of the offspring.
In evolutionary terms, the best strategy for any parent in the…
