LS15 Mid-Term Flashcards
What are the steps of the scientific method?
1) Make observations
2) Formulate hypothesis
3) Make a prediction
4) Conduct an experiment
FiIl in the blank: Scientific thinking can tell you when you should ______.
change your mind
Is maze running influenced by genes? Explain.
- Yes, there is evidence that maze running in mice influenced by genes
- An experiment took “smart” mice (those good at maze running) & mated to have offspring. They did the same thing with “dull” mice. Then the best of the best mice were mated while the worst of the worst mice mated (top 20% and bottom 20%). They continued this over several generations and found that found that the bright mice did well and the dull mice did poorly.
How can you increase your experiment’s power?
1) Randomize subjects across control and experimental group
2) Control your study
3) Use a double-blind design
The better ______ your experiment is, the more _______ we should have in its results.
controlled, confidence
Should we let pseudoscience and anecdotal observations influence our beliefs?
No! (even though they can be almost unbearably appealing.)
Define scientific method/scientific thinking.
A highly flexible and often nonlinear process that can be used to explore a wide variety of thoughts, events, or phenomena, not only in science but in other areas as well
What are the 5 basic elements to scientific thinking?
Make observations.
Formulate a hypothesis.
Devise a testable prediction.
Conduct a critical experiment.
Draw conclusions and make revisions.
O-H-T-C-C!
Describe empirical knowledge.
It is based on experience and observations that are rational, testable, and repeatable.
What kind of process is scientific thinking?
Empirical process
What does scientific thinking always start with?
Observations (or noting apparent patterns or cause-and-effect relationships.)
What 2 things must a hypothesis accomplish to be useful?
- Establish an alternative explanation for a phenomenon
- Generate testable predictions
Can you prove that a hypothesis is 100% true?
No, but as more evidence accumulates, we can be more confident.
A good, testable prediction will have it so that, if our hypothesis is true, then our ________ will always be true.
Prediction
What is a critical experiment?
An experiment that makes it possible to decisively determine whether a particular hypothesis is better than the alternative hypotheses
What is an independent variable?
Some entity that can be observed and measured at the start of a process, and whose value can be changed as required.
What is a dependent variable?
One that can also be observed and measured, but whose response is created by the process being observed and depends on the independent variable.
What does controlling variables mean?
It means attempting to minimize any differences between a control group and an experimental group other than the treatment itself.
What is the placebo effect?
The frequently observed, but poorly understood, phenomenon in which people respond favorably to any treatment.
What is beneficial about blind experimental design?
Can reduce biases that may arise from the participants’ expectations
What does it mean for an experiment to be randomized?
The research participants are randomly assigned to the experimental and control group & thus no one has an influence on group composition
To draw clear conclusions from experiments, control and experimental groups should differ only with respect to the _______. Differences in outcomes between the groups can then be attributed to the ________.
treatment of interest, treatment
What is a hypothesis?
A proposed explanation for a phenomenon
What is a scientific theory?
An explanatory hypothesis for natural phenomena that is exceptionally well supported by empirical data
Which tends to be broader in scope: theories or hypotheses?
Theories
What is replication?
The process of repeating a study
What is positive correlation?
A relationship between variables in which they increase (or decrease) together.
What is pseudoscience?
Individuals make scientific-sounding claims that are not supported by trustworthy, methodical scientific studies
What are anecdotal observations?
Based on just one or a few observations, people conclude that there is or is not a link between two things
(i.e. lucky t-shirts, horoscopes, MMR vaccine causing autism)
Can scientific thinking give us insights into value judgments and other non quantifiable, subjective information?
No.
What characteristics are shared by all living organisms/living systems?
- Cellular structure
- Metabolism
- Sensitivity/responsiveness to the environment
- Homeostasis
- Growth, development, reproduction
- Evolutionary adaptation
What are the 5 central themes that recur throughout living things?
- Systems
- Pathways and transformations of energy and matter
- Information flow, exchange, and storage
- Evolution
- Structure and function
Why is the phrase “survival of the fittest” misleading?
“Survival of the fittest” is not even in the first 4 editions of The Origin of Species → it then is mentioned in the 5th a lot and it stuck
What is an evolutionary successful organism?
An organism with greater reproductive success than other individuals in the population
Fitness is measured…
- Relative to other genotypes/phenotypes
- In a specific environment
- By reproductive success
There is no _____ success. There is only _____ success.
absolute, relative
What is fitness?
a measure of the reproductive output of an individual with a particular phenotype relative to the reproductive output of individuals of the same species with alternative phenotypes
What do we expect fitness to do over time?
Increase
What is evolution?
- A change in allele frequencies in a population
What is a mutation?
A direct alteration of the base-pair sequence of an individual’s DNA so that one allele is changed to another (ex’s: power plant, UV radiation, chemicals)
Describe gene flow/migration.
Within a population some individuals leave or new individuals arrive, thus changing the overall allele frequencies.
What is genetic drift?
A random change in allele frequencies (in a population)
What are the 3 conditions for natural selection?
1) Variation of traits
2) Heritability
3) Differential reproductive success
What are the 4 agents of evolution?
- mutation
- migration (gene flow)
- genetic drift
- natural selection
List examples of traits that make an individual more likely to die, but also make them more likely to be selected by mates.
- Feer (males have big antlers → females choose males w/ largest rack of antlers even tho antlers make life difficult)
- Frigate bird males (females choose mates based on the size and color of the pouch → but the big sack makes it hard to blend in from predators)
- Peacocks (males w/ big feathers are more attractive but it makes it harder to fly)
Sexual selection leads to _______.
Trade off
What is the significance of snakes/guns regarding nature vs. nurture?
- Snakes have the same reaction everywhere/all ages (sweaty skin/increased heart rate) whereas guns cause no response in babies or many cultures.
- We have the wrong instincts because the world is changing so quickly.
Is the human brain a blank slate?
No. Some feelings and behaviors don’t need to be learned.
