Counter Intuitive Darwinian Logic Flashcards
(8 cards)
Why do Langurs practice infanticide?
When a male is displaced the new male often kills the infants
To further his own reproductive success - infanticide frees females to become pregnant sooner and so gives the male more time to father his own offspring before also being overthrown
What is group selection?
Suggests an individuals’ behaviours are adaptations that assist the survival of the group e.g. reproducing less to avoid overexploitation of resources
Groups with individuals that practice self-restraint or do something to benefit the group survive better
What are the problems with group selection?
Individual selection will usually be stronger. Groups with the characteristics necessary for group selection are rare
What is self sacrifice in worker honeybees?
Leave stinger and part of the abdomen behind and she then dies
Stinger has backward facing barbs to stick into the skin
They practice kin selection and so sacrificing themselves they save their reproductive investment
How do honeybee stings work?
Muscles and nerve causes sting stylets to drill into flesh
Muscle contractions cause venom to be pumped down stylets
Alarm pheromone is also released which causes other members of the hive more likely to sting
Drives the intruder away
Most effective when the stinger detaches from the body
What is sex change in Anthias fish?
Females change into males when a larger dominant male dies and leaves an openining in the population
