BIOL 208 (January 27, 2014)
o Ex. red squirrels adopting baby squirrel of another organism
Individual donating food at their own cost while the adopted squirrel
o Ex. Host bird may not be able to discern the difference between own
offspring and another organisms of a totally different species.
Parasitic baby bird then kicks out other real offspring of the parent
out of the nest
o Voluntary and Involuntary (mom doesn’t know)
o Ex. Baboons
Bonded male will fight off other males
• If 2 unbonded males show up, one will fight the bonded male
and the other will have sex with the female.
o Unbonded and fighting male is altruistic. Getting
harmed for the benefit of the other unbounded male.
o This is reciprocal altruism (take turns)
Must be able to recognize individuals and have
a memory of what they did before. (No need for
trust… but is based on actions of other
individuals. If the baboon bails out after having
sex with the female, then the cheated baboon
will just not help him ever again.)
o Why does it persist?
Should not be favoured due to natural selection
Doing it for the good of the species (group selection)? NOPE
• Things don’t act for the good of the species
• Acting against individuals own fitness levels does not
compliment animal nature o Altruism