Behavioral Ecology Flashcards
What is behavioral ecology?
The study of organisms and their interactions with their environment on an evolutionary basis
How are heritable responses to stimuli coded?
Genetically coded
What are heritable behaviors encoded by genes subject to?
Evolutionary processes such as genetic drift and natural selection
What is proximate cause?
How the action occurs
What is ultimate cause?
Why the action occurs
Three-spined sticklebacks are small, spiny fresh or salt-water fish that have elaborate mating behaviors which include nest building and defense. Male sticklebacks in mating season have bright red bellies that are attractive to female mates. Males build nests in the rocky or sandy substrate near shore and then protect the nest from other red things, on the assumption that red things are males hoping to eat their eggs. Experiments have shown that males do not react to the presence of other sticklebacks, or stickleback-shaped things, that are not red. Instead, they react exclusively to color, attacking any shape that is red.
What is the proximate cause of the stickleback attack behavior?
A red visual cue
Three-spined sticklebacks are small, spiny fresh or salt-water fish that have elaborate mating behaviors which include nest building and defense. Male sticklebacks in mating season have bright red bellies that are attractive to female mates. Males build nests in the rocky or sandy substrate near shore and then protect the nest from other red things, on the assumption that red things are males hoping to eat their eggs. Experiments have shown that males do not react to the presence of other sticklebacks, or stickleback-shaped things, that are not red. Instead, they react exclusively to color, attacking any shape that is red.
What is the ultimate cause of the stickleback attack behavior?
To protect their offspring
What is relatedness?
The fraction of alleles that two individuals have in common
Sexual selection is. . .
a mode of natural selection that postulates the theory that certain physical traits increase success in obtaining mates
The equation for inclusive fitness is. . .
individual fitness + relatedness (relative fitness)
r = relatedness (proportion of shared genes)
B = benefit to the recipient (how many more offspring are produced)
C = cost to the altruist (how many fewer offspring are produced)
Hamilton’s rule states that if rB>C. . .
altruism can occur via natural selection
According to Hamilton’s rule (rB > C), altruistic behaviors can be maintained in a population when
A) the altruist and recipient are first cousins
B ) costs of an altruistic act are balanced by how many genes the altruist and recipient share
C) the costs of altruistic act with a stranger are balanced by benefits incurred
D) Relatedness combined with an increase in fitness more than balance the fitness costs to the altruist
E) none of these.
D) Relatedness combined with an increase in fitness more than balance the fitness costs to the altruist
Male fitness is calculated as the total of how many offspring he has that survive to reproduce + ½ the number of kids his sibling has that survive to reproduce.
Consider two brothers, Chirpy and Silent Bob. Chirpy mates with 2 females, and fertilizes 10 eggs from each female. Chirpy dies from parasites before he has the chance to mate again. Silent Bob lives to the end of the breeding season and mates with 5 females, fertilizing 10 eggs from each female. All eggs have a 10% chance to survive to become adult crickets.
What is Silent Bob’s fitness?
6
What is fitness?
How well an individual survives and passes on its genes
What is individual/direct fitness?
Genes contributed to the next generation directly by an individual through reproduction
