week 1 - scientific thinking and darwin

Question 1

five steps to the scientific method

Answer 1

1. make observation
2. formulate hypothesis
3. make a prediction
4. conduct the experiment
5. conclusion/analysis

Question 2

how does a hypothesis differ from a theory or prediction?

Answer 2

hypothesis - is a proposed explanation for an observation made
a theory - an explanatory hypothesis for natural phenomena that is supported by empirical evidence, repeatedly tested and considered fact
prediction - possible outcome based on empirical evidence

Question 3

with more and more observations made about something, do you eventually prove a hypothesis to be true?

Answer 3

NO - overtime, you can continue to have increasing confidence that a hypothesis is true, stuff could also be anecdotes

Question 4

self correcting process

Answer 4

if a hypothesis does not work with your observations and tests made, you will change your hypothesis as you go on

Question 5

control in a study

Answer 5

to try and make the study exactly the same for each group participating except for the thing that you are testing

Question 6

control group in a study

Answer 6

group in the study that is not receiving the variable that you are testing

Question 7

random testing

Answer 7

to make a study as random as you can, so you can see how it affects all people instead of one subset

Question 8

double blind studies

Answer 8

study where information is withheld from from the participants until the end of the study

Question 9

pseudoscience

Answer 9

collection of beliefs or practices mistakenly regarded as being based on the scientific method

Question 10

anecdotes

Answer 10

only collected when you notice things - very personal observations

Question 11

superstitions

Answer 11

when you see something and something else happen and imagine that there is a connection - no methodical observations

Question 12

nonequivalent group

Answer 12

extraneous variables that matter when you are trying to control everything in the experiment but one thing

Question 13

quantitative study

Answer 13

relating to, or measured by the quantity of something rather than its quality (ex. graphs)

Question 14

why should you say “this data suggests” instead of “this data proves”?

Answer 14

there are factors that cannot be proven, and there is no way that we can prove a hypothesis to be true

Question 15

evolution

Answer 15

change in allele frequencies within a population

Question 16

gene

Answer 16

section of dna instructing how to produce a trait

Question 17

allele

Answer 17

one variant of a gene (several may exist)

Question 18

how many copies of a every gene do we carry?

Answer 18

two, one from our mother and one from our father (two copies of the same gene)
- sometimes the two alleles are the exact same

Question 19

who is charles darwin?

Answer 19

the man who pretty much discovered evolution
1. finch variation and that each island unique sets of the same species because of evolution
2. also studied inheritance of genes

Question 20

three mechanisms of evolution

Answer 20

1. variation
2. heritability
3. differential reproductive success

Question 21

differential reproductive success

Answer 21

different variations traits will yield different reproductive tendencies, leading to differential reproductive success

Question 22

stabilizing selection

Answer 22

when individuals with extremes of the traits have reduced fitness, variance decreases (ex. birds with hella children)

Question 23

directional selection

Answer 23

when one extreme has a higher fitness than all others, variance decreases (ex. giraffes with longer necks)

Question 24

disruptive selection

Answer 24

when the extremes of the normal distribution have higher fitness than the intermediates (variance increases)

Question 25

why do turkeys stop evolving to have larger breasts?

Answer 25

because one of the mechanisms of natural selection has stopped working - must reintroduce whatever has stopped working

Question 26

agents of selection

Answer 26

things that influence selection

Question 27

examples of agents of selection

Answer 27

natural disasters, disease, temperature change, etc.

Question 28

fitness

Answer 28

the relative number of viable individuals that are contributed to the next generation

Question 29

positive correlation

Answer 29

natural selection leads to an increased frequency of traits that increases fitness, while reducing the prevalence of traits that lower fitness

Question 30

example of a trait that increases fitness

Answer 30

faster legs so its easier to run away from predators

Question 31

example of a trait that decreases fitness

Answer 31

having a lot of children so much that you cant feed them all in timely manner

Question 32

tradeoff between survival and reproduction example

Answer 32

family that has many children increases drs but there is no car that fits that many people, no job going to sustain that big of a family, etc.

Question 33

artificial selection

Answer 33

humans be the agents that determine reproductive success

Question 34

kin selection

Answer 34

idea that you would rather help your relatives reproduce than the willingness to help others

Question 35

sexual selection

Answer 35

when one sex acquires mates, and it results in male to male competition and female choice (ex. peacocking)

Question 36

does selection act on species, population, individuals, or genes?

Answer 36

individuals - people are the carriers of the genes, that are the physical unit of heredity, individuals are acted upon
- behavior has evovled over time to affect the individual and not the pop. or species

Question 37

which is more important in terms of selection? genotype or phenotype?

Answer 37

phenotypes - each person has their own phenotypic characteristics, and some genes dont even code for anything

Question 38

does natural selection increase or decrease variability in a population?

Answer 38

decrease - we are going to see more of the good traits than the bad traits overtime

Question 39

what is the outcome of natural selection?

Answer 39

adaptation - is the character that increases fitness

Question 40

four ways of evolution

Answer 40

1. natural selection
2. genetic drift
3. mutation
4. migration

Question 41

what can we see in genetic drift?

Answer 41

founder effect and bottlenecks

Question 42

founder effect

Answer 42

small number of individuals migrate to a new habitat (amish people with a bunch of fingers)

Question 43

bottlenecks

Answer 43

population gets reduced significantly in size (ex. big elephants had only one gene because only those survived)

Question 44

genetic drift

Answer 44

variance in the frequency of different genotypes in a population, often due to random chance

Question 45

migration

Answer 45

movement of individuals between populations

Question 46

mutation

Answer 46

a direct change in the genetic material of an organism, changing one allele into another
-completely random

Question 47

norm of reaction

Answer 47

all of the possible phenotypes that can be produced by a single genotype if it were raised in all possible environments

Question 48

steep norm of reaction

Answer 48

particular genotypes can produce many different phenotypes, depending greatly on the environment (ex. food consumed)

Question 49

flat norm of reaction

Answer 49

a particular phenotype always produces the same phenotype regardless of the environment (ex. eye color)

Question 50

how can a phenotype become so diverse?

Answer 50

depends on the type of environment that you are in
- also vast amount of variation in that gene pool to create a lot of phenotypic diversity (broccoli, cauliflower and cabbage are all from a single species)