Adaptation Flashcards
What are the three modes of selection? Which direction do they go?
Directional - linear
Stabilizing - toward middle (average)
Disruptive - spread out (favour extreme phenotypes)
What is the gall example of stabilizing selection?
Most small galls get parasitized, most of the large galls get eaten, so the average size is favoured
What is the evolutionary definition of adaptation?
A trait that increases the ability of an individual to survive and reproduce in its natural environment
A feature that has become prevalent in a population because of a selective advantage owing to its provision of improvement in some function
What type of selection is seen in Corollas? What aids in the selection?
Directional selection for larger plants
Bumblebee pollination strongly selects
What adaptation was used in an experiment with house flies and jumping spiders?
Mimicry was an adaptation to deter jumping spiders
What are the two types of defence against herbivores in Arabidopsis?
Physical defence with spines
Chemical defence with toxins
What were the results of the Arabidopsis experiment?
Control plants - selection favoured medium levels of chemicals and no physical
When herbivores and pathogens were absent, both defences were selected against
Herbivores select for one or the other, causing diversifying
What is altruistic behaviour? What drives it?
Putting yourself at risk to help a family member survive
Cost to both parties, number of times, relatedness to self.
What is kin selection? What is inclusive fitness?
Kin selection - natural selection based on indirect fitness gains
Inclusive fitness - the sum of direct fitness and indirect fitness
What is the reason for long necks in giraffes?
Competition against other males for mates
What was the adaptation that was needed in finches?
Beak size (depth and width) increased due to a decrease in food supply but then returned to normal after generations
