Social Games and Genic Selection Drive Mammalian Mating System Evolution and Speciation

Area of Science:

• Evolutionary Biology
• Behavioral Ecology
• Genetics

Background:

• Traditional mating system theories focus on resource defense economics.
• These models struggle to explain stable mating systems across diverse environments or shifts without ecological changes.

Purpose of the Study:

• To propose an alternative theory for mating system evolution based on frequency-dependent competition among genetically determined behavioral strategies.
• To model evolutionary transitions among mating systems (promiscuity, polygyny, monogamy) considering competition, neighborhood choice, and paternal care.

Main Methods:

• Developed a theoretical model analyzing payoffs for competition, neighborhood choice, and paternal care.
• Conducted a phylogenetic analysis of 288 rodent species to test model assumptions and evolutionary patterns.

Main Results:

• The model predicts four stable mating system outcomes: promiscuity, polygyny, and monogamy, driven by the balance of cooperative and agonistic behaviors.
• Phylogenetic data support the model, showing monogamy and polygyny evolve from promiscuity and are coadapted with paternal care in rodents.
• Transitions to monogamy correlate with higher subsequent speciation rates in rodent lineages.

Conclusions:

• Genetically based neighborhood choice and paternal care are key drivers of mating system evolution.
• The genic mating system theory complements resource-based theories and explains transitions independent of resource distribution.
• This framework offers alternative explanations for mismatches between resource ecology and observed mating systems, such as evolutionary inertia.