Despite a long history of study, consensus on a human-typical mating system remains
elusive. While a simple classification would be useful for cross-species comparisons, across …

Males and females often exhibit different behaviours during mate acquisition, pair‐bonding
and parenting, and a convenient label to characterize these behaviours is sex role. The …

Sex-role evolution theory attempts to explain the origin and direction of male–female
differences. A fundamental question is why anisogamy, the difference in gamete size that …

How can the stunning diversity of social systems and behaviours seen in nature be
explained? Drawing on social evolution theory, experimental evidence and studies …

Coordinated pair bonds are common in birds and also occur in many other taxa. How do
animals solve the social dilemmas they face in coordinating with a partner? We developed …

Frogs and toads (Anura) exhibit some of the most diverse parental strategies in vertebrates.
Identifying the evolutionary origins of parenting is fundamental to understanding the …

Parental care is one of the most variable social behaviors and it is an excellent model
system to understand cooperation between unrelated individuals. Three major hypotheses …

The evolution of monogamy and paternal care in humans is often argued to have resulted
from the needs of our expensive offspring. Recent research challenges this claim, however …

Parenting in the burying beetle Nicrophorus vespilloides is complex and, unusually, the sex
and number of parents that can be present is flexible. Such flexibility is expected to involve …

Sexual conflict is inescapable when two parents care for offspring, because providing care is
personally costly, while the benefits of successful reproduction are shared. Previous models …