Project proposal

1. Can Reproductive Cessation Emerge? Modelling Competition and Dispersal Patterns Matthew Gwynfryn Thomas Supervisor: Ruth Mace

2. Long Live the Human Total loss of female fertility near middle age Can live for decades after menopause Doesn’t make evolutionary sense (!) Why not reproduce until death? Why did this evolve? Kachel, Premo & Hublin (2010). Grandmothering and natural selection

4. Common Hypotheses Nonadaptive? Limited oocytes Theories of ageing Do we need grandmothers? Adaptive: inclusive fitness benefits: For grandmother For mother For father and grandfather

5. Long Live the Whale Menopause and long post-reproductive life in cetaceans Short-finned pilot whales(Globicephalamacrorhynchus) Resident killer whales (Orcinus orca) What do humans and whales have in common? Johnstone & Cant (2010). The evolution of menopause in cetaceans and humans

6. Dispersal Patterns Humans Whales Johnstone & Cant (2010). The evolution of menopause in cetaceans and humans

7. Kinship Dynamics Female relatedness to local males increases with age Competition for breeding positions Can select for reproductive cessation? Johnstone & Cant (2010). The evolution of menopause in cetaceans and humans

8. Kinship Dynamics Female-biased Dispersal Unbiased Dispersal Johnstone & Cant (2010). The evolution of menopause in cetaceans and humans

9. Hypothesis Can reproductive cessation and a post-reproductive lifespan evolve because of local mating competitionand sex-biased dispersal?

10. Agent Based Modelling (ABM) Simplified, simulated, malleable version of reality Global patterns of behaviour not pre-defined Observed behaviour emerges from simple rules and local information

11. Agent Based Modelling (ABM) Examples: Schooling fish Flocking birds Foraging ants Primate socialorganisation Altruism

12. Agent Based Modelling (ABM) Examples: Schooling fish Flocking birds Foraging ants Primate socialorganisation Altruism

13. Agent Based Modelling (ABM) Examples: Schooling fish Flocking birds Foraging ants Primate socialorganisation Altruism

14. Agent Based Modelling (ABM) An individual agent has: Properties Perception Rules and actions Multiple experiments Parameter sweep 10,000 years in five minutes Based on Kachel, Premo & Hublin (2010). Grandmothering and natural selection

15. The World Made up of patches with limited breeding spots 1 patriline (up to three generations) 3 unrelated breeding females Population of 900 people split into 150 patches Based on Kachel, Premo & Hublin (2010). Grandmothering and natural selection

16. The Experiments Keep life history parameters constant (menarche, IBI, fertility and mortality curves) Vary dispersal and competition rules/rates Track age at reproductive cessation over time Based on Kachel, Premo & Hublin (2010). Grandmothering and natural selection

17. {Simplified} Human Life Cycle Ageing Female-biased Dispersal Females disperse when sexually mature Younger males may disperse if no room to breed Reproduction Monogamous If room to breed Death

18. The Results Emergent reproductive cessation? With competition for breeding spots Inclusive fitness benefits may outweigh the costs of cessation Will strict monogamy introduce male menopause?

19. Software Life Cycle

20. {A More Complex} Human Life Cycle Breeding hierarchies Younger females Older males Grandma can remarry Polygyny Male-biased dispersal, bisexual dispersal

21. Questions?