BIO 141 1st Edition Lecture 3 Outline of Last Lecture II. Developing Relationships: Plants & PeopleIII. Babylon & BeerIV. Non-vascular PlantsOutline of Current Lecture V. Scientific MethodVI. Scientific TheoryVII. Double Blind ExperimentVIII. VariablesIX. ModelsX. SystemsCurrent LectureScience Depends on Skepticism and Accuracy- Ideally scientists are skeptical and unbiased.- Scientists strive for: o Accuracy: Correctness of measurements.o Reproducibility: Repeatability of results. Repeating studies or tests is replication. Scientific Method- Identify question  form testable hypothesis  collect data to test hypothesis  interpret results  report for peer review  publish findings.- If hypothesis is rejected after interpreting results, then go back to forming a testable hypothesis and create a new one.Hypothesis- Testable experiment.Scientific Theory- Description or explanation that has been supported by a larger number of tests and is considered by experts to be reliable. These notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.Natural Experiment- Involves observation of events that have already happened.Manipulative Experiment- Conditions are deliberately altered for one variable and others are constant. Controlled Study- Comparing a treatment group to a control group that hasn’t gotten treatment.Blind Experiment- Researcher doesn’t know which group has been treated until after the data has been analyzed. Double-Blind ExperimentVariable- On a graph:o Dependent variable is Y (vertical)o Independent variable is X (horizontal)- In each study there is one dependent (response) variable and one or more independent (explanatory) variables. - The dependent or response variable is affected by what happens to the independent explanatory variable. Variables Examples- Rainfall (explanatory), crop (response)- Growth rate (response), sun exposure (explanatory)- Voter apathy (explanatory), percent voter turnout (response)- Age (explanatory), height (response)Models- Simple representations of phenomena.- Allow scientists to study complex systems and predict the effects of conditions that are too difficult to create and control.- When multiple models agree, scientists gain confidence.- Can be physical, model organism, mathematical models, or other types. Systems- Networks of interdependent components and processes with materials and energy flowing from one to another. - Central concept in environmental science.- Examples: ecosystems, climate systems, economic systems, geologic systems. System Characteristics- Can be open or closed. - Closed: self-contained and receives no inputs of energy or material from outside.- Open: system that takes input from surroundings.- Throughput: energy flows in and out of the system. - Positive feedback loop: when a flow leads to compartment changes that further enhancethe flow. - Negative feedback loop: dampens flow.Stability of Systems- Equilibrium: changing littler over time. - Disturbance: periodic destructive events such as fire or flood.- Resilience: ability of system to recover quickly from disturbance. - State Shift: severe disturbance in which the system does not return to normal but instead changes some of its state variables. System Characteristics- Emergent Properties: characteristics of a whole, functioning system that are quantitatively or qualitatively greater than the sum of the system’s parts.- Example: The human body is a system of flows and compartments but from that system emerges emotions, ideas, painting, dance, etc.Consensus & Conflict- Scientific consensus: general agreement among informed scholars. Stems from a community of scientists who collaborate in a cumulative, self-correcting process.- Paradigm shifts: Great changes in explanatory frameworks. Occur when a majority of scientists agree that an old explanation no longer works very