The evolutionary history of primate mating systems

Area of Science:

• Evolutionary biology
• Primatology
• Behavioral ecology

Background:

• Inferring the evolutionary history of complex behaviors like sociality and mating systems is challenging due to the lack of fossil evidence.
• Previous research utilized Bayesian phylogenetic methods to reconstruct ancestral states of social grouping behavior in primates.
• This study extends phylogenetic analysis to investigate the evolution of primate mating systems.

Purpose of the Study:

• To reconstruct the evolutionary history of primate mating systems using phylogenetic methods.
• To identify the ancestral mating system and subsequent transitions in primate evolution.
• To compare the evolutionary trajectories of mating systems with social organization.

Main Methods:

• Bayesian phylogenetic comparative methods were employed.
• Ancestral states of mating systems were inferred across the primate phylogeny.
• Transition rates between different mating system states were estimated.

Main Results:

• The ancestral primate mating system is inferred to be polygynandrous.
• Two derived mating systems, harem-polygyny and monogamy, evolved later in primate evolution.
• Significant transition rates were observed from polygynous states to monogamy, with no transitions out of monogamy.
• Nocturnal primates showed parallel evolution of mating systems from polygynandry to harem-polygyny and monogamy, while diurnal primates exhibited co-evolution with social organization.

Conclusions:

• Primate mating systems have evolved from an ancestral polygynandrous state towards derived states of harem-polygyny and monogamy.
• Monogamy appears to be an evolutionary endpoint in primates, with no observed reversals.
• The evolution of mating systems, particularly monogamy, occurred late in primate evolution and is linked to social organization in diurnal species.