Lecture 2 - Scientific Methodology and Evolution Flashcards
Are philosophy and mathematics science? and what about statistics?
No and statistics are the bridge between mathematics and science
What is science?
the systematic study of the structure and behavior of the physical and natural world through observation and experiment.
What are the principles and goals of science?
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
What is a hypothesis?
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.
What is the scientific theory?
a generally accepted explanation for a set of observations supported by data.
How is the word theory used?
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
What is the scientific method?
the scientific method is a method of research with defined steps that include experiments and careful observation
What are the steps of the scientific method?
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
Null vs alternative hypotheses?
Null hypothesis HO: will not
Alternative hypothesis HA: will
Independent vs Dependent variable?
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
treatment vs control group?
treatment group: receives the treatment
control group: receives no treatment or placebo
standardized variable?
you should identify any variables that can affect the results of the experiment: think lurking variable
replication of experiment?
replication: refers to the number of individuals in the treatment or control group ānā.
- 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).
Data collection?
what data will you collect from your treatment and control groups? how will you measure it etc.
analysis?
analyze the results from the data collection in something like a graph: conclusion you can reject or accept null hypothesis
Statistical analysis?
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
What is evolution?
a change in the heritable characters in a population over time.
what is macroevolution?
evolution above the species level: creating a new species
what is a character in evolution?
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
what does it mean for a character to be heritable?
can be passed from parents to offspring through their genes
what is natural selection?
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.
adaptation?
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
what are the 3 categories of adaptation?
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
adaptation for a porcupine?
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
what are the 3 conditions necessary and sufficient for natural selection to cause a population to evolve?
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)
