social evolution Flashcards
what do eusocial societies include?
give 2 insects and 1 mammal that are eusocial.
caste of sterile workers, either permanently or conditionally
2 insects:
- ants/termites
- bees/wasps
mammal: naked mole rats
define eusocial
a social system where cooperative care of young and a reproductive division of labor occur within multigenerational group
a colobopsis ant ruptures its abdomen spilling toxic goo onto enemy, killing both enemy and itself. this demonstrates that eusocial insects usually do what?
eusocial insects display altruistic self-sacrifice in many cases, to defend nest and social group
what is altruism?
hurting yourself to help others
inndividual vs group selection
Group selection – Groups that have altruistic behavior are more likely to survive than groups lacking altruistic individuals.
Individual selection – Individuals that are better at surviving and reproducing are more likely to pass on their genes, even if it means acting in their own self-interest.
which selection, group or individual, has much stronger effect on evolution than the other?
individual selection
natural selection can act on 3 levels. what are they?
between groups within a population
between individuals within a group
between genes within an individual
what is direct and indirect fitness? what about inclusive fitness?
direct fitness - measure of reproductive (genetic) success based on number of offspring that live to reproduce
indirect fitness - measure of genetic success of an altruistic individual based on number of relatives that they help to survive and thus reproduce
inclusive fitness - measure of individual’s total contribution to genes (direct + indirect)
______ are similar to jellyfish and includes the man of war.
they are not a single organism, but comprised of multicellular _____ with different functions.
operate much like a _____ insect colony.
siphonophores
zooids
eusocial
slime mold - the social amoeba
this amoeba is a ______ that cooperates and behaves altruistically towards ________
during food _______, they aggregate into ______
they form _____ stalks with a _____ body
only the amoeba in the ______ reproduce while the ones on the stalks are _______ so they can better disperse the spores
protozoan; relatives
scarcity; slug-like colonies
reproductive; fruiting
fruiting body; altruistically supporting them
portuguese man of war has a gas filled float that plays a role in positive buoyancy and used as a sail to catch wind. what’s this structure called?
pneumatophore
the only zooid that ingests food, unigue to the man of war, is called?
gastrozooid
a polyp that has tentacles, unique to man of war. what’s it called? what’s it for?
tentacular palpon
to capture prey
specialises in nermatocyst production
this is a structure in the man of war that is released from the colony of zooids when they mature. it is ________.
gonodendron. it includes:
1) gonophore - medusa containing female/male
2) palpon - derived gastrozooid
3) nectophore - medusa used for locomotion
4) jelly polyp - reduced nectophore, function unclear
hymenopterans (wasps, bees, and ants) have ___________ males which have ____ set(s) of chromosomes instead of ___. this means they have ___ allele(s) at each genetic loci. (females are diploid)
males are produced via __________ from unfertilised eggs (they only inherit mtoher’s DNA). this makes ______ in the same generation more related to each other compared to other species.
haploid; 1; 2; 1
parthenogenesis; females
what is the haplodiploidy hypothesis?
relatively higher relatedness of full sisters in haplodiploid populations promotes altruism among siblings and consequently, the evolution of eusociality
does the haplodiploidy hypothesis fully explain eusociality?
no
what is the monogamy hypothesis in eusociality?
lifetime monogamy ensures siblings are highly related, making obligate sterile workers, and thus eusociality more likely to evolve
caste variation in eusocial societies is influenced by which 2 factors mainly?
social and ecological influences
how do ants and wasps remove reproductive conflict within their eusocial colony?
ants - hold workers with developing ovaries captive, or queen marks competitors and workers hold them captive
wasps - remove workers’ eggs
define collective behavior in animals.
non-independent behavior - individuals coordinating and synchornising their actions
pulling vs anchoring
pulling - successfully guiding others along new path
anchoring - failing to guide others, return to group
an animal that demonstrates pulling, anchoring and “voting” on the routes is the _____ baboon.
olive
in polistes dominula bees, subordinates gain ___ than dominant helpers, but they ___ more in future by inheriting nest and its helpers. this is a risk worth taking because ___.
less; more
finding a nest is risky and usually starts off w low chances of reproductive success
in lazuli buntings, _____ plays an impt role in territory settlement and pairing.
by permiting the browner-colored birds into their group, dominant males gain by _______.
coloration
fertilising more eggs and having someone care for them
reciprocal altruism hypothesis
altruism btwn non-kin mcan evolve where compensation for altruistic actions are delayed or returned later which balances out costs and benefits
in clownfish, subordinate males wait around territories awaiting them to vacate. the territorial male has no ___ or ____, thus it is tolerated.
gains; losses
an animal that practises reciprocal altruism is the ____
bat
in wild turkeys and _______ manakins, males form pairs to _____ females. in wild turkeys, the pair are usually __________.
long-tailed; brothers
kin selection hypothesis
indirect fitness benefits explain why some individuals delay independent breeding, become nonbreeding helpers, or aid others to survive and reproduce.
_________ give alarm calls when an aerial predator is spotted. this brings greater danger to themselves due to exposure. this is more performed when they are in the presence of close _____.
in taking survival risk to ensure sirvival of kin, they gain _______ fitness instead of _______ fitness.
ground squirrels; kin
inclusive; individual
siberian jay males in ________ groups emit more _____ calls when in groups consisting of ____.
breeding; mobbing; kin
across 44 breeding bird species, it was shown that inidviduals will offer more helping effort when there is high probability of ________. If not, they help less and predominantly (mainly) direct their helping to their ____.
inheriting the territory; kin
what is the group augmentation hypothesis?
individuals survive better by living in groups
what is the pay-to-stay hypothesis?
parents allow non-kin to stay in group if they help lighten the load of parental care
in a type of cichlid, non-related kin offer _____ help to stay in a group to gain ___________ and increase likelihood of ____________.
parental; defense; inheriting territory
from 1959 to 1990, population of seychelles warblers on Cousin Island _________ due to conversation efforts, _____ hypothesis and ______ hypothesis.
increased; ecological constraints; life history
define ecological constraints hypothesis
when resources become limited, young will delay dispersal and remain in antal territory to help raise relatives
when resources become limited, young will delay dispersal and remain in antal territory to help raise relatives. what hypothesis is this?
ecological constraints hypothesis
life history hypothesis
high survival rates create surplus of individuals leading to habitat saturation which can drive cooperative breeding where individuals work together to raise offspring, making sure that more young survive even if resources are limited
what is the benefits of philopatry hypothesis?
benefits of delaying dispersal are outweighed by costs of dispersing
in meerkats, females evicted from groups suffer _______ and ________, causing likelihood of conception to _____. they can reutrn to become ______ helpers to _____ females.
severe stress; reproductive suppression; extinguish; cooperative; dominant
a study experimentally manipulated reproductive suppression in female _____ by injecting ________.
treated females becomes _______ helpers and were:
1) less _____ by dominant females
2) less likely to be completely ____ from group
overall, this produced more helpers per pup
meerkats; contraceptives
subordinate/cooperative
attacked
evicted
evolution of cooperation is large the result of natural selection on ______ instead of ______.
individuals; groups
