Unit 1 Q & A
|Why do male sticklebacks turn red? Give a causative explanation using all four of Tinbergen's aims of ethology.||Causation- Male body color is correlated with dancing in front of a female|
Development- Red body color develops during courting.
Function- Red color attracts females and lets them know that that male is ready to mate and wards off other males. The brighter the red color, the more females will be attracted.
Evolution- Red body color may have evolved as a species recognition cue for 3-spined sticklebacks so that females would choose the correct males
|Which of Tinbergen's four aims of ethology are explanations of proximate causation vs. ultimate causation?|| Proximate causations are the causation and development of the behavior. |
Ultimate causations are the function and evolution of the behavior.
|What are the three conditions necessary for a trait frequency to change under the mechanism of natural selection?||There must be a struggle for existence, variation among individuals in a species, and a heritability of traits.|
|Explain why behaviors might not always evolve as predicted by natural selection theory.||Behaviors might not always evolve as predicted by the natural selection theory because animal's environments are always changing and do not often stay the same long enough for a trait that was necessary at one time to fully evolve before another trait is now better suited for the new environment.|
|Why must we consider the evolutionary relationships of multiple species before drawing conclusions in a comparative study?|| Because some species evolved through convergent evolution. Species evolve similarly containing analogous structures similar in function, but are not closely related. |
(ex. birds and bats both have wings but they are not closely related at all.)
|What distinguishes individual learning from cultural transmission?||Individual learning ensures variation within an individual and trait frequencies change within a generation. Cultural transmission refers to variations within individuals and trait frequencies change across generations.|
|How does artificial selection shape behavioral phenotypes?||Artificial selection is identical to natural selection except for the fact that humans control the reproductive success of alternative types within the population. Through artificial selection desired behavioral phenotypes will become more prevalent quicker than they would through natural selection alone because male and female animals that possess the desired behavioral phenotypes will be bred together ensuring that the desired behavioral phenotype is passed on.|
|How does natural selection shape behavioral phenotypes?||Natural selection uses variation among individuals in a species, heritability of traits, and struggle for existence to shape behavioral phenotypes. Through these ways mutation, genetic recombination, and migration or gene flow influence which behavioral phenotypes produce the highest level of fitness. Over time, the traits that produce the highest level of fitness will become more popular than the traits that don't.|
|Describe an example of behavior that seems to have a simple Mendelian pattern of inheritance.||The ability of male flies to produce a song seems to have a simple Mendalian pattern of inheritance. The period gene, when mutated, leads to a mutation of the fly's song. The song is too fast or too slow and will not attract females. The disruption of 1 gene completely disrupts a behavior.|
|How is variation in behavior maintained in a population?||Through artificial selection. Variation occurs among behavioral phenotypes and some of this variation is heritable. Individuals with the desired traits are bred to produce more of those traits. Eventually more individuals with the desired trait will exist than individuals without the desired trait.|
|What can knockout mutations tell us about genetic control of behavior?||Knockout mutation studies show that genetic control is based off of just 1 gene. The removal of just 1 gene and completely disrupt a behavior. However, 1 gene does not cause a behavior.|
|How does variation still work with a strong natural selection?|| Mutation? Usually considered too slow.|
Gene Flow? Counterstrikes selection!
Changes in environment? Very weakened but animals change because their environment changes.
|Why would evolution occur more rapidly when a trait has high heritability?||Because if it has high heritability that means it is more easily passed down from generation to generation and it is more easily selected for by natural selection therefore altering that populations gene pool all together.|
|What are the main criticisms of the adaptationist program?||Chance events such as mutation, recombination, drift, and gene flow maybe more important than natural selection.|
Hypotheses about adaptation are untestable since they are questions of a historical natural and are not subject to experimentation
Behavioral ecologists ignore constraints that would prevent selection from acting upon each trait individually.
|Why must we consider Adaptationist program/main criticisms between closely related species before testing hypotheses?||We must consider Adaptationist program/main criticisms between closely related species before testing hypotheses because they allow for statistical independence while comparing closely related species.|
|How does the complexity of a molecule influence its effectiveness as a chemical messenger?||The more complex a molecule is the longer its half-life and the larger the level of communication. Molecular messengers work at cell to cell communication level (neurotransmitters with a very short half-life and travel only very short distances to pheromones which can be released outside the body and last for long periods of time).|
|What do studies of 0M/ 2M mice tell us about the role of hormones during development?||Hormones play an important role in development. These hormones influence development in possibly changing the way the mouse will respond and act later in life. 2M males have high levels of testosterone and very low levels of parental care. 0M mice have low levels of testosterone and high levels of parental care. Therefore, males with higher levels of testosterone have a lower fitness according to females and males with lower levels of testosterone have higher fitness according to females.|
|Explain how the bowing and cooing of male ring doves is both responsive to and responsible for hormone secretion.||Courtship, bowing and cooing, of male ring doves is responsible for hormone secretion. Courtship stimulates the necessary hormone secretion for ovulation. The presence of a male, who is bowing and cooing and courting the female, and nest building materials are essential in ovulation. Hormones produce behaviors that lead back into the stimuli system. Courtship, bowing and cooing, is also responsive to hormone secretion. A male will bow and coo more if he senses the hormones secreted when a female is ovulating.|
|How do birds recognize specific songs?||A bird's HVC has neurons specifically tuned to the male's own song and those of familiar rivals. Birds have their own songs memorized and the songs of their neighbors.|
|If behaviors are unlikely to be the result of a single gene, why do mutants missing only one gene have abnormal behaviors?||Mendelian inheritance patterns suggest that some behaviors might be disrupted by a single gene because it is not 1 gene that leads to 1 behavior, but the absence of 1 gene disrupts behaviors.|
|Important:||Learning is a relatively permanent change in behavior as a result of experience.|
|How do innate behaviors, such as taxis and reflexes, become modified with frequent exposure to stimuli?||Through habituation and sensitization. Habituation means an animal is becoming less sensitive to stimuli over time. Sensitization means an animal is becoming more sensitive to stimuli over time.|
|What distinguishes classical vs. operant conditioning?||Classical conditioning works with a behavior that is already present. Classical conditioning is the experimental pairing of a conditioned and unconditioned stimulus. Operant conditioning works on an unknown behavior but ends with a reward. In operant condition learning that occurs when a response by animals is reinforced by reward or punishment. Different from classical because behavior occurs first and then learning.|
|Why are some stimuli more easily paired with particular behaviors?||Some stimuli are more easily paired with particular behaviors because of constraints. Some animals will only respond the desired way with a certain stimuli. For example, rats can learn to associate taste with nausea but not with electric shock. Rats can learn to associate sound with shock but not nausea.|
|Which types of learning are restricted to a narrow sensitive period during development and why might this be adaptive?||Imprinting is restricted to a narrow sensitive period during development because some animals have no fear when they are first born, but however that fear level heightens as time goes on.|
|How did difference in study animals and scientific approaches between ethologists and comparative psychologists fuel the nature vs. nurture controversy?||Ethologists observed animals in the wild through field observations. The animals were in their natural environment. Also, the ethologists tested the instinct theory and used related species. Psychologists did lab experiments in a laboratory environment. The animals and the testing situation were easily controlled. Also, the psychologists used model species and tested the learning theory.|