1. Altruism By: Ashley Stiles, Kelsey Detels, and Katie Pearce

2. What is Altruism? Altruism: behavior that reduces an individual’s fitness while increasing the fitness of others in the population “selfless” behavior Belding’s ground squirrel - loud call

3. Altruism cont. Often evident in colonies (E.g.) workers in a honeybee hive will sting an intruder, and will die doing so

4. How does altruistic behavior evolve? How can organism pass on genes if it is killing itself? Inclusive fitness: the total effect an individual has on multiplying its genes by producing its own offspring and by providing aid that enables close relatives to increase the production of their offspring o Parents sacrificing for young=maximizing survival of their own genes o Helping close relatives reproduce

5. Kin Selection Definition: a phenomenon of inclusive fitness, used to explain altruistic behavior between related individuals Genes for altruism may be passed on if the individuals that benefit from selfless acts are themselves carrying those genes

6. Reciprocal Altruism In animal behavior, a selfless act is repaid at a later time by the beneficiary or by another member of the beneficiary’s social system