lec 32- behaviour and sociality Flashcards
what are the advantages and disadvantages of animals living in social groups?
benefit: increased vigilance, enhanced defence capability, cooperative foraging/hunting, improved defense of critical resources, dilution effect
costs: increased conspicuousness to predators, increased competition for food, increased competition for mates, increased chances for parasites, decreased certainty of paternity/maternity
are the edges of a colony more vulnerable to predation than middle?
yes
does parasitism increase with group size?
yes
why are large groups good?
-each member of a large group has a lower probability of being targeted by a predator than an individual, the individual who breaks away from the group is often more likely to be targeted
-competition for safest spot (center of school, herd)
why is cooperative foraging beneficial?
-easier to gain more energy
-e.g. Africa wild dogs can hunt prey larger than their own size
what are some other examples of cooperative foraging?
-group feeding in baleen whales with bubble nets
-white pelicans driving fish into shallow water shores to trap them and eat them
when does self sacrificing altruism occur?
happens in groups with close genetic relatives, known as kin
what is alarm altruism and what is the risk?
-when an individual gives out a warning call to alert the group, but increases risk for one self by potentially not escaping in time
why is warning calls common in female ground squirrels?
because they raise and protect their offspring, hence them calling to protect them
can helping behaviour evolve despite the cost of not reproducing?
yes, e.g. meerkats that have young gain help from other subordinate meerkats that don’t breed for years till apart of the dominat breeding group
what is the example of altruism seen in Florida scrub jays?
prior offspring of a couple or even relatives of the couple protect them and their current offspring from harm (Glen E Woolfenden and John Fitzpatrick)
do individuals most often help relatives based on the coefficient of relatedness (r)? what are the different r values between different relationships?
yes
offspring (parent and child) and full siblings = 0.5 r
grandchildren, half siblings, nephews, and nieces = 0.25 r
great grandchildren and cousins = 0.125 r
what formula proposed by William Hamilton explains altruism?
inclusive fitness = direct fitness + indirect fitness
what is kin selection?
selection arising from the indirect genetic benefits of helping relatives (high r values) raise offspring, rather than reproducing yourself
when does an altruistic allele increase in frequency?
when relatedness and benefit is greater than the cost
rb > C
is kin selection seen in white fronted bee eater birds?
yes, young birds often help their parents raise young which helps increase the reproductive success of the parents
does high certainty of paternity cause increased male parental investment?
yes, e.g. male giant water bug carries eggs of females it breeds with
what are the three components for genes and selection to act upon altruistic traits?
-a recognizable kin phenotype exists
-ability to recognize kin phenotype (smell, sight, sound etc.)
-preferential treatment of individuals with recognized phenotype
what is Eusociality?
a type of social structure common in insects and one vertebrate (naked mole rat) where most members never reproduce themselves but help rear offspring of a few dominant members (queen, and their one mate)
what is haploploidy and explain how it is beneficial?
-a mechanism of sex determination where males hatch from unfertilized eggs (haploid) and females from fertilized eggs
-sisters from a queen (mother) share 75% of their genes, while queens share 50% of genes with offspring, as such its more beneficial to them to help the queen raise more offspring (sisters) than producing their own offspring
are naked mole rats the only Eusocial mammal and are not prone to cancer making it a key research species?
yes
what allows for learning in humans?
synaptic plasticity, the dendritic spines on dendrites in our neurons change over time with learning
what is anthropomorphism?
the tendency to interpret animal behaviours in human terms
what is sociality a key for?
teaching, learning, and abstract thinking
does social group size increase the brain over time?
yes, it influences its growth and learning ability
what is one example of non-biological evolution?
teaching is a way for humans to pass information from one generation to the next instead of genes
who came up with “survival of the fittest” and “nature red in tooth and claw”?
-Spencer 1864
-Tennyson 1833
did Herbert Spencer say that evolution is the progressive development of the physical world?
yes, economics also follows survival of the fittest
do companies always compete to survive in the industry by following the demand of the consumers (selection) and advancing in technology (mutations) to prevent loss of the company (extinction)?
yes
