Final Exam Flashcards
what is altruism
a behavior where individuals risk their own fitness to increase the fitness of another
if individual selection trumps group selection, why and how do groups form?
because individual fitness can increase with a group living under certain circumstances
what is increased vigilance
when large groups have the advantage of spotting potential predators
what is the dilution effect
the safety in numbers that arises through swamping the foraging capacity of local predators
explain altruism between non-relatives
young have an increased fitness if living in a group than living on their own, but they have to help raise offspring
explain altruism between relatives
relatives share many of the same alleles, 50% are shared with parents, 50% is shared with siblings, and 25% is shared between nieces and nephews. altruistic behaviors can evolve between the relatives because of the alleles
what increases the chances of your alleles being passed down to another generation?
the survival of one of your relatives
who is william hamilton
he described how altruistic behaviors can be represented as a range in values depending on how related two individuals are to each other
what is direct fitness
organisms own success in passing on alleles
what is indirect fitness
the reproductive success of other individuals that carry the same alleles as you
what is inclusive fitness
an individuals total fitness (direct + indirect)
what is hamilton’s rule
an individual is more likely to help another if it benefit to the recipient, adjusted to the likelihood to shared genetic material, is greater than the cost to the helper
what is the equation of hamiltion’s rule?
r*B>C
what does r mean in the equation r*B>C
the coefficient of relatedness between the donor and recipient
define relatedness
the probability that 2 individuals share an allele due to recent common ancestry
what does B mean in the equation r*B>C
the benefit to the recipient arising from help
what does C mean in the equation r*B>C
the cost to the donor from helping
when does natural selection favor altruism?
when r*B>C ranges from 0-1
what does 0 mean in regards to natural selection and altruism
complete relatedness
what dose 1 mean in regards to natural selection and altruism
identical clones
is helping someone unrelated, advantageous?
no, not unless there is no cost
what did JBS Haldane state?
they stated “i would gladly lay down my life for 2 brothers or 8 first cousins”
what is the haplodiploid
which sex is determined by the number of copies of chromosomes
where are haplodiploid systems found? Hint: they’re only found in these types of insects
eusocial insects
what are the 3 requirements for eusociality
- reproductive division of labor
- overlap of generations
- cooperative brood care
true or false: worker bees sacrifice themselves instead of reproducing to protect the hive
true
queens and worker bees have an r value of what?
0.5
worker bees have an of value of what if they have the same father?
0.75
if daughters have daughters then how are the sisters related?
closely related
females have inclusive fitness if…
they help mom have more children (sisters) rather than reproducing on their own
how do kin recognize each other?
the green beard effect
who came up with the geen beard effect and what is it?
dawkins, and the green beard effect is when an allele has 3 traits:
1. recognizable phenotype
2. the ability to recognize the phenotype
3. and the preferential treatment to individuals with the phenotype
what is dictyostelium
the slime mold slug are composed of amoeba relatives
how do dictyostelium recognize kin?
a gene called CSA which allows dor amoebas to hook together
what is a parasitoid
a parasite that kills the host as a normal and required part of their development
what is the host manipulation by parasite?
any alteration in host phenotype induced by the parasite that has fitness benefits for the parasite
what is host manipulation an example of?
extended phenotype
what are the 3 categories that parasitoid manipulation of host behavior falls under?
- frequency of manipulation and the magnitude of its benefits to the parasitoid
- acquisition of phylogenetic and behavioral data to begin asking questions about how the manipulations evolved
3.determination of mechanisms through which parasitoids manipulation host behavior
what was the first record of parasitic manipulation?
amphibians harboring larval acanthocephalan parasites (spinyhead worms), which consists of a complex life cycle
describe the life cycle of the acanthocephalan parasite
adults are intestinal parasites of vertebrates, egg pass in the hosts feces and are eaten by an arthropod (amphipod)
in the amphipod an acanther hatches from the egg and enters the hemocoel where it develops into an acanthela
final larval stage in a cystacanth, which as the toothed proboscis but is retraced, and a cyst wall forms over the parasite
devo pauses until the intermediate hose is eaten by the definitive host, then the cyst ruptures and the parasite attaches to the intestines
describe the parasitic manipulation of a spider by a wasp
larva resides on the spider pupation, at which the spider is manipulation into producing a “cocoon web”
what is the name of the wasp that manipulates the spider?
polysphincta
describe the polysphincta life cycle
adult lands at center of web, immobilizes spider with venom, lays eggs on spiders back, eggs hatch and feed on spider. before spider dies, it builds a wasp cocoon in the center of the stabilimentum of the web. larva moves to construct a cocoon where it pupates
the wasp larva does not have direct contact with the spiders nervous system, so how does it manipulate the spider?
it accesses the spider’s brain by injecting high concentrations of ecdysone in the abdomen, which travels to the brain through the open circulatory system
explain how the ophiocordyceps unilateralis fungi manipulates ant hosts
spores of the fungus attaches to the cuticle of the ant. the spores germinate and break into the ants body by diffusing through the trachea. fungal cells begin to communicate and work together to form the mycelium which grows by feeding on the host organs, avoiding the vital ones. fungus then produces chemicals that cause the ant to climb to the top of a plant or tree and clamp mandibles to stay in place
how does the fungus manipulate the ant to move
it is hypothesized that the fungus severs communication between the brain and muscles, taking control of the muscles for ant movement
explain the process of the parasitic manipulation of the glyptapanteles and the caterpillar
wasp stings and injects eggs into caterpillar, caterpillar quickly recovers and resumes foraging, wasp larvae mature inside caterpillar and 2 weeks later, up to 80 larvae emerge from the caterpillar, 2 larvae remain inside the caterpillar while siblings pupate, and the caterpillar body is controlled to move back and forth violently to protect the wasp pupae
what is spontaneity
when one insect uses neurotoxins to hijack the decision-making ability of another
what is an example of spontaneity
when one insect uses neurotoxins to hijack the decision-making ability of another
whats an example of spontaneity
a cockroach and jewel wasp parasitoid
explain how the jewel wasp manipulates the cockroach
the jewel wasp stings and delivers venom into the first thoracic ganglia of the cockroach. GABA, located in the venom, inhibits the propagation of action potentials to the motor neurons, resulting in transient paralysis of the front leg muscles. second sting occurs and venom is injected into the supEG and the SEG of the roach. wasp then looks for hole, comes back and cuts off roach antennae and eats a small blood meal, pulls the roach in the hole, stings again, lays an egg in the cockroach, egg emerges and bites through the roach leg, and feeds on the roach for several days before burrowing further inside and eating the insides of the roach, pupates, and becomes a wasp
how many cerebral ganglia is the cockroach CNS comprised of?
2- the SupEG and the SEG
what do the supEG and the SEG control?
the expression of locomotive patterns that are generated by the thoracic ganglia
what does the thoracic ganglia contain?
networks of interneurons and motor neurons that generate the motor patterns for flight and walking
ancestral lineages experienced a shift from…
depending on smell to depending on sight
all tetrapods use the same family of genes to produce what?
odor receptors on the ends of neurons that grow inside their noses
when the genes that produces odor receptors experiences duplications, what happens?
for some, it resulted in new genes that can smell new smells, but in others it resulted in pseudo-genes (disabled olfactory genes)
how many olfactory receptor genes do mice have? how many of them are pseudogenes?
they have 1391 olfactory receptor genes with 508 as pseudogenes
how many olfactory receptor genes do humans have? how many of them are pseudogenes?
they have 802 olfactory receptor genes with 415 as pseudogenes
what could be a possibility for the shift form smell to sight
diet
what is the opsin gene?
this is the gene that old world monkeys and apes share that other primates lack, giving them the ability to see better in red and orange regions of the light spectrum
social evolution drove the expansion of what?
the primate brain
it is hypothesized that larger group sizes selected for what?
a larger neocortex region of the brain, so thus humans are differences than other apes
how are humans different from other apes
we are “ultra social”
what is the ultra social hypothesis experiment?
when researchers compare the mental skills of 105 two year olds to 106 chimpanzees and 32 orangutans. they gave subjects an identical series of dests which measured understanding of space, quantities, or physical causes and effects. they performed a spacial memory test and a social cognition test
what was the spacial memory test?
a toy was placed under 1 or 3 cups, and the subject needed to choose which cup contained the toy
what was the spacial cognition test?
it showed the subjects how to get a toy out of a tube testing to see if they can learn by observing
who is ralph haygood?
he studied the human genome and concluded the neural development and function evolved mainly through changes in noncoding regions of DNA
what was one important coding in noncoding regions of DNA?
the regulation of delivery to the brain
what was the significant of glucose transporters when comparing humans and other apes?
they found the glucose transporters are much more abundant in the brains of humans compared to other apes, but less abundant in our muscles in the body
what is the definition of the social brain hypothesis
it predicts that children rapidly develop social skills from others
what is the oxytocin hormone?
it is produced by the hypothalamus to foster mothering
oxytocin, vasopressin, vasotocin, etc. belong to a family of what?
neuropeptides that operate on sexual and reproductive behavior
what is the amino acid sequence that this family of neuropoptides follow?
cysteine-AA-AA-AA-asparagine-cysteine-proline-AA-glycine
what happens when oxytocin is released into the bloodstream?
it latches onto receptors in mammary glands to produce milk
- some latch onto neurons in the brain, altering a mothers behavior, facilitating bonding between mother and baby
how is oxytocin produced triggered?
by smelling in animals, and by sight in humans
what happens to oxytocin levels in women who have faced childhood trauma?
levels of oxytocin decrease when the women become mothers, interfering with their ability to form meaningful attachments with their offspring and mates
what does romantic love lead to?
a man and woman forming long-term bonds and exclusively having sex with their partners
what two neuropeptides have love co-opted?
oxytocin and vasopressin
what are some actions that elicit signal through the oxytocin-vasopressin pathways
touching, eye contact, and smiling
