Scientific Thinking 

Define Science

• what does science ^^encompass^^: observations, descriptions, experiments, and explanations of natural phenomena
• ==science== is an important pathway in the discovery and better understanding of the world we live
• ==pseudoscience==: scientific-sounding claims that are not supported by trustworthy, methodical scientfic studies
  • “four out of five dentists”
  • ==anecdotal observations==: based on only one or a few observations, people conclude that there is or is not a link between two things
  • superstitions
  • bad science leads to dangerous behavior
  • ex: do vaccines cause autism ?

limits of science

• the scientific method is above all, empirical
• value judgements and subjective info falls outside the realm of science
• doesnt do general moral statements nor gives insight to ethical problems
• technology is not science, it is the application of research
• ex: should we edit genes?

Define Biology

• what is ==biology==: the study of living things
• important ^^questions in bio^^:
  • what are the chemical and physical basis for life?
  • how do organisms use genetic info to build themselves and reproduce
  • what are the diverse forms that life on earth takes and how did it arise
  • how to organisms interact with each other and their environment

Describe scientific thinking

• what are some examples of %%scientific literacy%% in the modern world:
  • how reliable is DNA fingerprint evidence
  • why do allergies strike children from clean homes more than child from dirty homes
  • why do new agricultural pests appear more quickly than new pesticides
• what is ==biological literacy== : the ability to use the process of scientific inquiry to think creativty about real world issues that have a biological component, communicate those thoughts to others, integrate these ideas into your decision making
• scientific thinking is an empirical ^^process^^ that involves making : observation, hypothesis, prediction, experiment, conclusion
  • ex: phone not charging
  • ^^rarely linear^^
• what is scientific thinking ^^based on^^: experience and oberservations that are rational, testable, and repeatable
  • self-correcting

scientific method:

• when making an ^^observation^^, it mustn’t have: an apparent matter or cause and effect relationship

  • correlation does not equal causation

• what is a ==hypothesis==: a proposed explanation for an observed phenomenon

• what is a useful ^^hypothesis^^: must clearly establish an alternative explanation for a pheneomenon and generate testable and falsifiable predictions

  • ex: echinacea reduces the duration and severity of the symptoms of the common cold

• ==null hypothesis==: a negative statement proposing that no relationship exists between two factors

  • valid but easier to disprove
  • ex:echinacea has no effect on the duration or severity of the symptoms of the common cold

• ==alternative hypothesis==: impossible to prove that a hypothesis is absolutely and permanently true

• what is the goal of your ^^predictions^^: to propose a situation that will give a particular outcome if your hypothesis is supported but a differrent outcome if it is not

  • involves ^^“if…then”^^ statements
  • example of prediction: %%if%% echinasea reduces the likelihood of catching the common cold and the duration of the symptoms of a cold, %%then%% indivudals who take echinasea will have a %%lower%% likelihood of catching a cold and a %%shorter%% duration of cold symptoms
  • %%if%% echinasea reduces the likelihood of catching the common cold and the duration of the symptoms of a cold, %%then%% individuals who dont take echinasea will have a %%higher%% likelihood of catching a cold and a %%longer%% duration of teh cold symptoms

• what is a ==critical experiment== : one that makes it possible to decisively determine whether one hypothesis supported by evidence over all alternative hypothesis

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• the last step of the scientific method is: to draw ==conclusions== and make revisions to your hypothesis if needed

  • look for patterns and relationships in evidence
  • determine if findings and conclusions support hypothesis
  • if the result isnt what you expected, it doesnt mean its a wrong answer, it just means you need to revise your hypothesis and conduct further experimenets based on new observations

Describe key aspects of a well-designed experiment

• ==theories==: exceptionally well supported hypothesis, repeatedly tested, unlikely to be altered by any new evidence, broader in scope than hypothesis
  • ex: evolution, gravity

key terms

• ==treatmeants==: any experimental condition applied to individuals(does not have to be animal)
• ==experimental group==: a group of individuals who are exposed to treatment
  • ex: group exposed to epinichea
• ==control group==: group of individuals who are treated identically to the experimental group with one exception-they are not exposed to the treatment
• ==variables==: characteristics of an experiment that are subject to change
  • variables can be ^^independent^^ and ^^dependent^^
  • dependent variable ^^depends^^ on independent variable
• ==control variables==: minimizing any differences between control group and experimental group other than the treatment itself ; the things you consciously kept the same
  • ex: plants with same sunlight and water and soil
• ==placebo effect==: this is the phenomenon in which people respond favorably to any treatment
  • what highlights the need for a comparison of treatment effects with an appropriate control group : the placebo effect

designing experiments

• ==blind experimental design==: the experimental subjects do not know which treatment(if any) they are receiving
• ==double blind experimental design==: neither the experimental subjects nor the experimenter knows which treatment the subjects are receiving
  • which design is the ^^best^^: double blind experimental design (no bias)
• ==randomized experimental design==: the experimental subjects do not know which treatment (if any) they are receiving because it is randomized
• ==replication==: process of repeating a study
  • increases our confidence in results
  • helps isolate variables responsible for outcomes
  • experiments that can be repeated again and again are an effective defense against biases
• ^^biases:^^ can influence our behavior, including our collection and intepretation of data. with careful controls, it is possible to reduce the impact of biases

visual displays

• ^^visual displays^^ help us understand phenomena
  • title
  • y-axis: dependent variable
  • ==dependent variable==: created by the process being observed and whose value cannot be controlled
  • x-axis: independent variable
  • ==independent variable==: some measurable entity that is available at the start of a processs and whose value can be changed as required
  • data points
• how can a ^^graph^^ be ^^misleading^^:
  • ambiquity in labeling or scales
  • incomplete info on how data was collected
  • biases or hidden assumptions
  • unknown/unreliable data sources
  • insufficient/inappropriate context for data presentation

statistics

• ==statistics==: a set of analytical and mathematical tools designed to help researchers gain understanding from the data they gather

  • can help us make decisions

  • drawing conclusions based on ^^limited^^ observations is risky

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• statistics can also help us ^^identify relationships^^ (or lack thereof) between variables

  • ==positive correlation==: when one variable increases, so does the other

• ==statistical analyses== help us organize and summarize observations and experimental evidence

  • dont help us draw conclusions

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Describe how scientific thinking can be used to help make better decisions

• ^^evidence^^ gained from well-controlled studies designed in accordance with ^^good scientific thinking^^ can illuminate when we should ^^change^^ our minds
• we make choices everyday based on assumptions about out world; it is essential to ^^question^^ these ^^choices^^ and the veracity of our ^^assumptions^^

Describe the major themes in biology

• ==biology== is the study of life
• ^^characteristics of all living things^^: organism of one or more cells, uses energy to perform work, responds to external stimuli and environment, homeostasis , capable of growth and developing and repoduction, capable of evolving and adapting over time
• what are the ^^five central themes^^ in biology: evolution;structure and function; information flow, exchange, and storage ; pathways and transformation of energy and matter; systems