Test 2

Question 1

What are three reasons that female parental care is common in mammals

Answer 1

Females invest more resources (gamete production) into offspring thus would lose those invested resources if the offspring were to die. Females aren’t able to have as many offspring so the few offspring they have need to survive to pass on their genes; evident in the Bateman Gradient which found that female reproductive success does not increase when they mate with more males. Females are often the only ones present when the offspring are born so to pass on those genes they are the only ones that can ensure the offspring does not die

Question 2

What are three reasons that male parental care is common in fish

Answer 2

Males are often the ones left to defend the territory that has the eggs thus has invested more resources than the female and would not want to waste those resources. Females are not around when the eggs hatch making it so that the males are the only ones left to care for the offspring. To ensure their genes pass on thus ensure they are the only ones to fertilize the eggs, males defend the territory from other males

Question 3

What are the two darwinian puzzles and define them

Answer 3

Cooperation, when an organism does something that helps another at a cost to them and displaying for copulation which is dangerous for the males since it gives out their location, is energenetically costly to develop these structures and to perform these actions, and could injure them when they fight over females

Question 4

What is a solution to the darwinian puzzle of cooperation

Answer 4

kin selection: selection that works to increase the fitness of relatives. Used to ensure their genes are passed on since they share genes with relatives. Called inclusive fitness: when an individual acts to increase the survival and reproduction of non-descendent kin as well as themselves

Question 5

What is an example of kin selection

Answer 5

vampire bats that will regurgitate blood to share with bats that were unsuccessful in foraging. This could be harmful since they are giving up nutrients. Kin selection can be seen when the bats do this for siblings since they share 50% of their DNA thus, helping the brother would ensure that they can both reproduce and pass on their genes

Question 6

What is a solution to the darwinian puzzle of displaying for copulation

Answer 6

Dangerous behaviors allow the males to attract a mate which then allows them to have offspring thus, pass on their genes. Being able to have offspring extends to Darwin’s theory of selection since the organism is able to minimize risk enough to survive the possible predation and male to male competition for a mate while also maximizing reproduction by obtaining a mate and passing on its genes

Question 7

What is an example of displaying for copulation

Answer 7

Birds sing to attract females. In singing they are giving out their location not only to the female but also to predators. However, should they succeed in attracting a mate they are then able to reproduce and have offspring thus, pass on their genes

Question 8

What is an ESS and what ESS do lizard morph express

Answer 8

Evolutionarily stable strategy is a strategy that when adopted by a population cannot be invaded by any competing alternative strategy. Male lizards have a mixed ESS since there are multiple strategies employed by the various males and no one strategy is safe from being invaded by another

Question 9

What are Tinbergen’s four questions and do they address ultimate or proximate level explanations

Answer 9

The two proximate questions address how a behavior functions to help an organism and are What are the mechanistic causes of the behavior? How does the behavior develop? The two ultimate questions address why did this behavior evolve and the questions are How did the behavior evolve? What is the funciton of the behavior?

Question 10

What is a mating system and what are the four types

Answer 10

A way to describe who mates with whom. Polygyny: one male mates with multiple females, polgynandry: male and females mate with multiple partners, monogamy: one male mates with one female, polyandry: one female mates with multiple females

Question 11

What are key pieces of observational or experimental evidence that would align with each mating system

Answer 11

polygyny: a male lives with a group of females (harem), seen in greater spear-nosed bats
polygynandry: sex is used not only to reproduce but also to settle conflicts as seen in bonobo chimps
monogamy: both parents care for offspring like with mimic poison frogs where the male remembers offspring location and females provide food
polyandry: sex-role reversal; males incubate eggs like in jacanas or females are dominant like in bees

Question 12

What mating system would be expected for the monkeys and which one is least likely

Answer 12

The most likely system is polygynyandry since females live in groups with a single mate living with them as well as their offspring. The least likely system is monogamy since the monkeys live in groups making it very hard for males to ensure they are the only ones mating with a certain females

Question 13

What are the behaviors assigned to hawks and doves in the model

Answer 13

Hawks will always fight leading to a 50/50 chance agaisnt hawks with a cost for losing and will always win agaisnt a dove. Doves will always flee from hawks and agaisnt doves they will display at a cost and a 50/50 chance of winning

Question 14

What is the math for not saving a sibling but for saving 2 brothers and 8 cousins

Answer 14

A sibling would not be saved since that would create a risk to him that is not outweighed by the benefit. But saving 2 siblings would outweight the cost since they are half related to him or 8 cousins since they are 1/8 related to him. Saving them would essentially allow him to let his genes pass on even if he were to die

Question 15

What is the relatedness between sisters and their offspring in ants

Answer 15

sisters are .75 related while their offspring are only .5 related

Question 16

How would an evolutionary psychologist explain that men prefer younger women and women prefer older men

Answer 16

men prefer younger women since they are physically better to have offspring while women prefer men that are older since they are likely better established in the world and have more resources

Question 17

What are three hypotheses for preference-trait evolution and what are key features of them

Answer 17

sensory exploitation: which is when a trait becomes common since is exploits a pre-existing bias of the female
honest advertisement of male quality: when a trait indicates some heritable aspect of a male’s genetic or physiological quality
runaway selection: trait and preference become genetically correlated and co-evolve in a positive feedback loop that “runs away”

Question 18

What is a scenario that uses all three hypotheses

Answer 18

sensory exploitation in which birds with feathers on their heads exploit a preexisting bias in females leading to male offspring that have feather on their head which soon begins to become the most common trait. Runaway selection leads to female offspring of the males with feathers having a preference for males with feathers so they only mate with males who have feathers on their head while females without the preference mate with males regardless of the trait presence. This leads to selection for males with feathers on their heads. Honest advertisement of male quality would lead to feathers on head to show good quality wise a male is since they are able to dedicate so many/little resources to the development of it

Question 19

What are two examples that show understanding of Lorenz’s statement

Answer 19

Swordtail fish females prefer males with long tails. To figure out if the preference for long tails existed first or if the taild did, scientists glued long tails on platyfish, an ancestor of the swordtail fish, which did not have long tails and females were attracted to those males suggesting that the preference existed before the tails did
Tungara frog males produce whines while some add chucks to the whines. Females of all species prefer calls with whines and chucks. This shows that the chuck likely evolved after the whine did and that preference for both likely evolved before the chuck did in order for the chuck to become established

Question 20

Would Tinbergne agree with Lorenz

Answer 20

Tinbergen would likely agree since they are both classical ethologists and his famous 4 questions are aimed at finding why an animal behaves a certain way by looking at trait evolution

Question 21

What are plausible hypotheses for salamander vocalization using Tinbergen’s four questions

Answer 21

Mechanistic: if a male salamander were to be inhibited from developing a large song center then he will not vocalize during breeding season
Develop: if a male does not vocalize during breeding season then he will not be able to have offspring that season
Evolve: If a male salamander’s T is blocked he will not vocalize during breeding season
Function: if male doesn’t vocalize then female can’t guage how fit he is