ch. 16 brain and behavior Flashcards
Behavioral traits ___
vary
Darwin’s 3 prerequisites
- Heritable variation
- Variation contributes to phenotypic differences among individuals
- Causes variation in fitness (differential reproductive success)
Genes influence behavior at ____
different time scales
Behavioral Ecology
the science that explores the relationship between behavior, ecology, and evolution to elucidate the adaptive significance of animal action
Behavior can evolve by ___
natural selection
Animals use ____ to control behavior
neurons
-animal nervous systems evolved through the co-opting of genes with other functions
What was the earliest fossil of brain evidence?
530 mya
Haikouichthys
-vertebrate brains are divided into specialized regions with organization remaining relatively conserved through time
Nikolaas Tinbergen
laid the foundation for study of behavior in an evolutionary framework
-won Nobel Prize for behavioral studies
-experiments in herring gulls revealing nature of innate behaviors
Individual Selection
differential fitness of individuals causes some genotypes to outcompete others and spread in the population
*individual selection happens more rapidly than group selection
Group selection
differential fitness of behaviors supporting a group and causes some groups to outcompete others
General Rule:
organisms are reproductively selfish
Benefits of Sociality
- increased vigilance
- dilution effect
- enhanced defense capability
- cooperative foraging/hunting
- improved defense of critical resources
Costs of Sociality
- increased conspicuousness to predators
- increased competition for food
- increased competition for mates
- decreased certainty of paternity/maternity
- increased transmission of disease/parasites
Dilution Effect
“safety in numbers”
Cooperative foraging
when prey is abundant, hunting in packs can result in more energy per day as pack size increases
Coefficient of Relatedness (r)
the probability that two individuals share identical copies of a particular allele or is a proportion of alleles that are likely to be shared between two individuals
Kin selection
selection arising from the indirect benefits of helping relatives
Altruism
occurs whenever a helping individual behaves in a way that benefits another individual at a cost to its own fitness
Inclusive Fitness
an individuals total fitness + reproductive success = direct fitness
increase in the reproduction of its relatives carrying the same alleles = indirect fitness
*Inclusive fitness = direct fitness + indirect fitness
Hamilitons Rule
*when altruism is favored
an altruistic allele increases in frequency when:
rB > C
r= coefficient of relatedness between donor and recipient (ranges from 0 to 1)
B= benefit to recipient arising from help
C=cost to donor from helping
Microbes
can display a range of behaviors
EX: aggregating to form spores
Plants can be _______.
sensitive to light and touch and communicate by sending and receiving chemical signals
Behavior evolves just like
any other trait
The beginning of nervous systems evolved ?
early in the animal lineage
Many behaviors are ?
innate
-innate behaviors provide clear examples of behavioral evolution
