final all content - lec 13 to 23

evolutionary explanations for behaviors

genes, environment, behaviour

evolutionary explanations for phenotypic differences between sexes of some organisms

sexual traits and behaviours

understanding the evolution of cooperation and conflict

social behaviours

exploring effects of genes outside of the organism with those genes

extended phenotypes

evolutionary explanations for susceptibility to disease

evolutionary medicine

evolutionary explanations for non-adaptive phenomena

aging

applying evolutionary thinking to some of the most pressing problems of our time

pathogen evolution

______ and _________ influence phenotypes

genes, environment

_______ _________ shapes behaviours

natural selection

environmental effects on trait values can be described as _________

plasticity

two kids of questions in biology

how/what and why (proximate vs ultimate)

examples of proximate

how does an individual manage to carry out an activity?

what is the causal relationship between the organism’s genes and behaviour?

examples of ultimate questions

why has that trait evolved?

why has this behaviour evolved and how has it changed over evolutionary time?

why do bees/wasps behave oddly in the fall

little bit drunk

what makes bees/wasps drunk in the fall

consume fermented nectar or rotting fruit, which produces ethanol that impairs their motor functions

why are drunk pollinators better for plants

impaired state increases the time they spend on a single flower, which leads to more effective pollination

phenotype equation

z = g + e + g*e

phenotype = genes + environment + gene by environment interaction

phenotypes reflect both ______ and _________ effects

genetic, environmental

rover-sitter polymorphism

Drosophila melanogaster larvae, where individuals exhibit distinct foraging strategies

rover

travel long distances to feed

sitters

remain in a small area to feed

within food patches, ______ move much more than ______

rovers, sitters

in the absence of food, rovers and sitters both move ____ often and for ________ distances

more, similar

for gene

foraging, 2 alleles, 2 expression patterns

foraging behaviour for alleles

homozygote rover ~2.4

heterozygote ~1.8

homozygote sitter ~0.9

rover benefit and cost

find more food but expend more energy

which strategy is the best

depends on environment

evolution by natural selection requires

variation in trait, genetic basis for trait (heritability), variation in fitness

can behaviours evolve by natural selection

yes

environmental effects on foraging

foraging behaviour decreased as time spent and they were deprived of food

_________ _____ describes effect of environmental variable on phenotype

reaction norm

large genetic effect, small environmental effect

small genetic effect, large environmental effect

complex gene x environment interaction

if there is an environmental effect on the phenotype of __________ _______ individuals then there is plasticity

genetically identical

daphnia phototactic behaviour

attracted to or repelled by light

food is in light, so are predators

sexual dimorphism

individuals of different sexes of same species have different genotypes and/or phenotypes

types of sexual dimorphism

differences in gametes, differences in reproductive organs, other sex-associated phenotypic differences

anisogamy

unequal sized gametes

4 ways to analyze sexual dimorphism

size, armaments, behaviours, ornaments

size

males usually larger than females in mammals

armaments

dramatic, sex-specific differences in weapons such as horns, antlers, tusks, or enlarged claws; driven primarily by intense intrasexual competition among males for mates or resources

examples of armaments

moose antlers, flies eye distance

behaviours

sex-based differences in actions often driven by reproductive, evolutionary, and neural factors

examples of behaviours

birds of paradise male dances, greater sage-grouse males dances

ornaments

distinct physical differences in plumage, coloration, or structures between sexes arises primarily through sexual selection, where males typically evolve more exaggerated features to attract mates or compete for dominance

examples of ornaments

widow birds plumage and male peacock displays

________ selected traits function to enhance mating success

sexually

what goes into fitness

natural and sexual selection, survival, reproductive rate and number/quality of mates

two types of sexual selection

intrasexual selection and intersexual selection

what determines the strength of sexual selection

number and quality of mates

intrasexual selection

competition

intersexual selection

choosiness

operational sex ratio

anything that alters the receptivity of one sex to mating or their potential for remating

ex. males are busy reading news instead of mating

what drives differences in potential reproductive rates

differences between egg and sperm, sperm expensive and widely available. egg resource rich and not many

parental investment theory

sexes differ in their reproductive gamete investment

members of the sex that invest _____ will compete among themselves to mate with members of the sex that invest _____ in offspring

little, more

if only investment in offspring is gametes, then MALE fitness limited by

access to fertilizable gametes

if only investment in offspring is gametes then FEMALE fitness is limited by

access to resources

if males are limited by access to mates and females aren’t

if only investment in offspring is gametes, then we predict __________ in males and _______ in females

competition, choosing

forms of intrasexual selection

pre copulatory and post copulatory

determine # of copulations and success of copulations

examples of pre copulatory

fighting behaviour, social status, territoriality

examples of territoriality

elephant seals, males fight for control of the beach, whoever wins gets to mate with all the females on the beach, resulting in high mating success

examples of post copulatory

mate guarding, copulation duration, sperm removal, sperm plugs, anti-aphrodisiacs

alternative reproductive strategies

having variation in traits and behaviour within a sex like bluegill sunfish

bluegill sunfish

males are either sneaker or satellite

sneaker fish

smaller and watch females reproduction and swoop in at the last minute

satellite fish

males that have evolved to look like females and act like them to take their reproduction

side blotched lizard

orange, blue, yellow, alternate in main frequency over time

orange lizard

defend large territories, very aggressive, attack and defeat blue

blue lizard

defend smaller territories, detect and root out yellow

yellow lizard

sneaker male on orange, mimic throat colour and behaviour of females to take out

prediction of rock paper scissor lizards

success of each strategy in obtaining mates is dependent on frequency of other strategies in population

the fitness of a strategy is highest when that strategy is ____ in population. this means selection is ________ __________ _________

rare, negative frequency dependent

mate choice

any trait of one sex that biases the mating success of the other sex toward the preferred type

what are the categories of mechanisms that individuals choose based on

visual cues, tactile cues, acoustical cues, olfactory cues

example of female choice and visual cue

tail length in long tailed widowbird, longer is more preferred

tail length experiment

natural, reduced, elongated, sham, L > N, S > R

tail manipulation experiment also asked if tail length impacts male-male competition

no, tail length only influences female choice

example of of acoustic cues and female choice

tungara frog females prefer complex calls when given the choice between two synthetic calls

relative strength of sexual vs natural selection ______ across environemnts

varies s

strong competition for mates in ______ environments

urban

stronger predation from bats in _____ environments

forest

as a consequence, urban tungara frogs make far more complex calls than forest frogs and all

females prefer them

why are elaborate traits/behaviours common?

preferred by mates, so there is selection for elaboration

direct benefits

involve direct natural selection on individual making choice, chooser produces more offspring

indirect benefits

involve genetic benefits to offspring of individual making choice, chooser producers offspring of better genetic quality (more fit)

benefits of female choice

choosiness based on resources instead of male attributes, so male trait is indicator of resources

selection for male traits as indicators of resource provisioning or other direct benefits

territory quality, defense, parental care, lack of parasites

indirect benefits of female choice

females prefer male traits that indicate good genes, so offspring from matings with preferred males should have higher fitness

is peacock display size an indicator of good genes?

yes. males with more eyespots produce offspring that survive better

indirect benefit

bluegill sunfish males are the ones who take care of children. mating with them is what kind of benefit

indirect

parental males offer ______ benefit to females, because they

direct, defend nests and care for young

satellite/sneaker males offer _______ benefit to females because

indirect, good genes lead to offspring growing faster and surviving better

parental males adjust their ______________ when they sense offspring have been sired by other males

level of care

what are the two things that influence parental investment

gamete expenditure and parental care

cooperative breeding

individuals beyond a pair assist in raising young, commonly by providing food and protection

eusociality

overlapping generations
single individual is dominating the reproduction
division of labor, specialized roles

types of social behaviour

cooperation and altruism