Lecture 2 - Scientific Methodology and Evolution

Question 1

Are philosophy and mathematics science? and what about statistics?

Answer 1

No and statistics are the bridge between mathematics and science

Question 1

What is science?

Answer 1

the systematic study of the structure and behavior of the physical and natural world through observation and experiment.

Question 2

What are the principles and goals of science?

Answer 2

the goal is to understand reality and the principles are
- interested in facts not opinions or beliefs
- numerical information
- any uncertainty is quantified and openly shared

Question 3

What is a hypothesis?

Answer 3

a suggested explanation for an event or observation. Hypothesis must be testable and falsifiable. No number of experiments can prove that a hypothesis is correct but a single experiment can prove it is incorrect.

Question 4

What is the scientific theory?

Answer 4

a generally accepted explanation for a set of observations supported by data.

Question 5

How is the word theory used?

Answer 5

the word theory is commonly used outside the scientific world to describe a simple hunch: scientists use the term to describe a broadly accepted explanation for an occurrence

Question 6

What is the scientific method?

Answer 6

the scientific method is a method of research with defined steps that include experiments and careful observation

Question 7

What are the steps of the scientific method?

Answer 7

step 1: make observations
step 2: ask a research question
step 3: formulate testable hypotheses
step 4: make predictions
step 5: design experiments to test hypotheses
final steps: present work, peer reviewed, and then publish it

Question 8

Null vs alternative hypotheses?

Answer 8

Null hypothesis HO: will not
Alternative hypothesis HA: will

Question 9

Independent vs Dependent variable?

Answer 9

independent variable: variable the researcher intentionally makes different between groups.
dependent variable: the variable that the researcher predicts will be affected and measures to determine effect aka response variable

Question 10

treatment vs control group?

Answer 10

treatment group: receives the treatment
control group: receives no treatment or placebo

Question 11

standardized variable?

Answer 11

you should identify any variables that can affect the results of the experiment: think lurking variable

Question 12

replication of experiment?

Answer 12

replication: refers to the number of individuals in the treatment or control group “n”.
- it can also refer to the number of times you repeat the experiment with new groups
NOTE: the more replicates: the more confidence you can have that the results are not due to chance(more statistical power).

Question 13

Data collection?

Answer 13

what data will you collect from your treatment and control groups? how will you measure it etc.

Question 14

analysis?

Answer 14

analyze the results from the data collection in something like a graph: conclusion you can reject or accept null hypothesis

Question 15

Statistical analysis?

Answer 15

used to determine the probability that the results you find are just due to random chance. In science, there needs to be a statistically significant difference to reject the null hypothesis. Generally p<0.05 is statistically significant

Question 16

What is evolution?

Answer 16

a change in the heritable characters in a population over time.

Question 17

what is macroevolution?

Answer 17

evolution above the species level: creating a new species

Question 18

what is a character in evolution?

Answer 18

a character is an observable feature that can vary among individuals. if there is more than one variation of the character , we call those variation traits.
example: flower color is a variable character in pea plants. there are 2 traits for this character; flower color is either white or purple

Question 19

what does it mean for a character to be heritable?

Answer 19

can be passed from parents to offspring through their genes

Question 20

what is natural selection?

Answer 20

one mechanism by which populations can evolve;
Natural selection is the process by which living organisms with traits that help them better survive and reproduce in their environment are more likely to pass those traits to their offspring. Over time, this leads to a gradual change in the characteristics of a population as the traits that enhance survival become more common.

Question 21

adaptation?

Answer 21

an inherited trait that increases an individuals probability of surviving ad reproducing in a particular environment; if a population evolves by natural selection, we describe it as having adapted to its environment

Question 22

what are the 3 categories of adaptation?

Answer 22

1) structural: a feature of a organisms body that helps it to survive and reproduce. Example: jellyfish bodies are transparent to hide from predators.
2) behavioral: responses made by an organism that help it to survive and reproduce. example: sounds made by whales to help them communicate, navigate and hunt prey
3)physiological: a body process that helps an organism to survive/reproduce. example: cobra creates venom to protect itself

Question 23

adaptation for a porcupine?

Answer 23

1) structural adaptation: sharp quills for protection from predators, sharp claws for digging
2) behavioral adaptation: curls into a ball when threatened, digs burrows in which to nest and rest
3) physiological adaptations: tongue can stiffen and penetrate soil, ears sensitive to low frequencies to detect ant sounds

Question 24

what are the 3 conditions necessary and sufficient for natural selection to cause a population to evolve?

Answer 24

1) there is character variation in the population
2) the variation in that character is heritable
3) there are fitness differences between individuals with different variations of the character (traits)