Chapter 9 Biology

instincts (innate behaviors)

don't require any environmental input to develop, present in all in individuals in a population and do not vary much from one individual to another

paternity uncertainty

due to possibility females mate with multiple males, any of whom could be the father

reproductive investment

energy mother will expend in the growth, feeding, and care of offspring

group selection

evolution of a trait that is beneficial for the species or population while decreasing the fitness of the individual exhibiting the trait

direct fitness

fitness measured by individual's total reproductive output

indirect fitness

fitness measured by reproductive output that individuals bring about through seemingly altruistic behaviors towards close kin

polygamy

individuals have multiple mates 1. polygyny 2. polyandry

monogamy

individuals mate and remain with just one other individual

fixed action

innate behavior triggered in response to a specific signal called a sign stimulus, requites no learning, does not vary, once started must run to completion

reciprocal altruism

kindness toward unrelated individuals

kin selection

kindness towards close relatives

total reproductive output

lifetime number of offspring a male can produce

4 rules of female choosiness

1. mate only after subjecting a male to courtship rituals 2. mate only with a male who controls valuable resources 3. mate only with a male who contributes a large parental investment up front (nuptial gift) 4. mate only with a male that has a valuable physical attribute

3 conditions for reciprocal altruism to evolve

1. repeated interactions among individuals, with opportunities to be both donor and recipient of altruistic-appearing acts 2. benefits to the recipient that are significantly greater than the costs to the donor 3. ability to recognize and punish cheaters, individuals that are recipients of altruistic-appearing acts but do not return the favor

2 differences in sexual behavior of males/females

1. sex with the greater energetic investment in reproduction will be more discriminating when it comes to mating 2. members of the sex with less energetic investment in reproduction will compete among themselves for access to the higher-investing sex

pair bond

male and female spend high proportion of time together

communication

action or signal on the part of one organism that alters the behavior of another organism

behavior

any and all of the actions performed by an organism, often in response to its environment or to the actions of another organism

polyandry

one female mates with multiple males

polygyny

one male mates with multiple females

mate guarding

consequence of (attempt to reduce) paternity uncertainty, reduce male's vulnerability, happens if male intends to raise offspring he benefits by minimizing risk in danger zone

female

sex that produces larger gamete

male

sex that produces smaller, motile gamete

sexual monomorphism

sexes of species are indistinguishable behaviors: both parents invest equally in caring for offspring, mating system tends toward monogamy, both sexes are equally choosy when selecting a mate

sexual dimorphism

sexes of species differ in size or appearance behaviors: one parent invests more in caring for the offspring, mating system tends toward polygamy, female is usually choosier when selection mate, mate usually competes for access to mating opportunities with other sex

honest signal

signal that cannot be faked and that is given when both the individual making the signal and individual responding to it have the same interests, carries the most accurate info about an individual or situation

language

specific type of communication in which arbitrary symbols represent concepts and grammar dictates the way the symbols can be manipulated to communicate and express ideas

inclusive fitness

sum of individuals indirect and direct fitness

3 common types of communication

1. chemical - pheromones released by individual into environment that trigger behavioral responses in another individual 2. acoustical - sounds that trigger behavioral responses 3. visual - individuals display visual signals of threat, dominance, health, vigor

learning

behaviors greatly influenced by individuals environment, altered and modified over time in response to past experiences

prepared learning

behaviors learned easily by all or nearly all individuals

altruistic behaviors

behaviors that come at a cost to the individual performing them while benefiting a recipient (define costs and benefits in terms of contribution to individual's fitness)