FÖ2 (Ch. 1-2) Basics of behavioural ecology & principals of social evolution

Mendelian inheritance

• Discovered dominant and recessive traits

• 3 laws:

  • Law of dominance

  • Law of independent assortment

  • Law of segregation:

    • 2 alleles per locus, one from each parent

Natural selection, genetic drift

Evolutionary processes that decrease genetic variation

Mutation, migration

Evolutionary processes that increase genetic variation

Pleiotropy

When a gene affects multiple traits

Hamilton’s law

If rB>C then altruistic behaviour can evolve

r = relatedness (coefficient)

B = benefit to recipient

C = cost to the helper

By-product hypothesis

Non-adaptive altruism that happens because selection against it would impair other neccessary functions

Ex. helper birds staying in parent territory helping with siblings because selection against would cause the birds to not care for their own offspring

Kin selection

Altruistic behaviour toward relatives can increase indirect fitness

• More likely to help with siblings if parents are monogamous

Facultative altruism

temporary loss of direct fitness (with potential for indirect fitness gain followed by personal reproduction)

Ex. mammals and birds that are helpers

Obligate altruism

permanent loss of direct fitness (with potential for indirect fitness gain)

Ex. eusocial insects with sterile castes

Strategies

Hereditary behaviours