Module 1 - Science and the Scientific Method.pdf

BIO 10.01 Science and the Scientific Method Albert Matthew C. Lazatin, MSc What is science?  Science is a methodical approach to studying the natural world Science is a determination of what is most likely to be correct at the current time with the available evidence...

BIO 10.01 Science and the Scientific Method Albert Matthew C. Lazatin, MSc What is science?  Science is a methodical approach to studying the natural world Science is a determination of what is most likely to be correct at the current time with the available evidence ○ Can be verified or examined by other scientists Science relies on evidence from the natural world examined and interpreted through logic  Science is non-dogmatic Science doesn’t prove, disprove, or replace religious or spiritual beliefs; science explains the natural world only Science cannot make moral or aesthetic judgements Science is based on assumptions The world is real  Humans can accurately perceive and attempt to understand the physical universe By T. R. Shankar Raman - Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=94454993 Natural processes can explain natural phenomena and events Human perceptions may be inaccurate or biased Scientific knowledge is contingent rather than absolute By Nobu Tamura email:[email protected] http://spinops.blogspot.com/ - By Jes from Melbourne, Australia, CC BY-SA 2.0, http://spinops.blogspot.com/2013/01/iguanodon-bernissartensis.html, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=5158019 https://commons.wikimedia.org/w/index.php?curid=78481061  Scientific explanations are probabilistic By Jerome laurens - Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=84237142 The scientific method What is the scientific method? A process of using comparative critical thinking to answer scientific questions There is no such thing as a definitive set of scientific methods ○ Methods vary across different fields The scientific method is non-linear By ArchonMagnus - Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=42164616 “Steps” included in the scientific method Observation and formulation of a question Observation of a phenomenon, event, or “problem” Based on the observation, a question is formulated ○ How did this happen? ○ Why is this happening? The question must be answerable Hypothesis An educated proposal to answer the scientific question Has to be testable and falsifiable ○ Hypotheses that fail can be proven correct later on and vice versa Experimentation Design methodology to prove or disprove the hypothesis ○ Not all disciplines use the same methodology Results must be reproducible and verifiable Control setup and experimental setup  Variables Independent variable ○ Controlled/manipulated Dependent variable ○ Affected by the independent variable Controlled variable ○ Constant between experimental and control groups Example 1 Which variable is dependent? A. Plant height B. Fertilizer C. Plant species Example 1 Which variable is dependent? A. Plant height B. Fertilizer C. Plant species Example 1 Which variable is independent? A. Plant height B. Fertilizer C. Plant species Example 1 Which variable is independent? A. Plant height B. Fertilizer C. Plant species Example 2 Which variable is dependent? A. Zone of inhibition B. Antibiotic used C. Bacteria Example 2 Which variable is dependent? A. Zone of inhibition B. Antibiotic used C. Bacteria Example 2 Which variable is independent? A. Zone of inhibition B. Antibiotic used C. Bacteria Example 2 Which variable is independent? A. Zone of inhibition B. Antibiotic used C. Bacteria Evaluation All conclusions need to be analyzed thoroughly to verify them Scientific findings should be made public Peer review is critical in the sciences Vigorous questioning of existing ideas is central to the scientific process Other definitions  A confirmed or agreed upon Fact empirical observation or conclusion Knowledge based on real occurrences  A statement that isn’t Belief scientifically provable May be correct or incorrect Outside the realm of science  A well-substantiated explanation for natural phenomena that has been Scientific Theory tested and verified but can still be falsified Supported, modified, or replaced as new evidence and methods are made available  Different from the non-scientific definition of “theory” ○ A hypothesis is tested extensively before becoming a theory Theories aren’t likely to change ○ Theories can change, but only if there are lots of observations and evidence a theory can’t explain The theory of spontaneous generation Spontaneous generation - life arising from nonliving matter Widely accepted from classical antiquity until the 17th century By Ian Alexander - Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=120373498 Questioning spontaneous generation Francesco Redi’s experiment https://bio.libretexts.org/@api/deki/files/8443/OSC_Microbio_03_01_Rediexpt.jpg?revision=1  (a) (b) John Needham (a) and Lazzaro https://bio.libretexts.org/@api/deki/files/61364/Spallanzani_Experiment.png?revision= Spallanzani’s (b) experiments 1&size=bestfit&width=661&height=610  Louis Pasteur’s experiment https://bio.libretexts.org/@api/deki/files/8445/OSC_Microbio_03_ 01_Pasteur.jpg?revision=1 Scientific theory vs scientific law Theories are explanations while laws are patterns seen in large amounts of data Theories do not “graduate” into laws with more evidence; theories remain theories while laws remain laws  Laws are frequently expressed Ex. Newton’s Second Law as equations ○ Equations show the relationships between F =m(v/t) = ma variables F = force m = mass v = velocity t = time a = acceleration Gause’s law Competitive exclusion principle ○ Two species cannot occupy the same niche in a habitat ○ If two species compete for the same resource, one would outcompete the other  Invasive species demonstrate extreme competitive exclusion By NOZO - Self-photographed, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=3569899 CC0, https://commons.wikimedia.org/w/index.php?curid=141382153 By Charles J. Sharp - Own work, from Sharp Photography, sharpphotography.co.uk, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=80031074 References and further reading 3.1: Spontaneous Generation. 2016 Jul 10. Biology LibreTexts. [accessed 2024 Aug 14]. https://bio.libretexts.org/Bookshelves/Microbiology/Microbiology_(OpenStax)/03%3A_The_Cell/3.01%3A_Spontaneous_Generation. Alviar-Agnew M, Agnew H. 2016 Apr 4. 1.6: Hypothesis, Theories, and Laws. Chemistry LibreTexts. [accessed 2024 Aug 14]. https://chem.libretexts.org/Bookshelves/Introductory_Chemistry/Introductory_Chemistry/01%3A_The_Chemical_World/1.06%3A_Hypothesis_Theories _and_Laws. Genovesi E, Blinderman L, Natale P. 2019 Jun 30. 3.2: Experimental Design. Biology LibreTexts. [accessed 2024 Aug 14]. https://bio.libretexts.org/Bookshelves/Introductory_and_General_Biology/Unfolding_the_Mystery_of_Life_-_Biology_Lab_Manual_for_Non-Science_ Majors_(Genovesi_Blinderman_and_Natale)/03%3A_The_Scientific_Method/3.02%3A_Experimental_Design. Hartline R. 2022 Jan 13. 1.3: The Myth of Spontaneous Generation. Biology LibreTexts. [accessed 2024 Aug 14]. https://bio.libretexts.org/Bookshelves/Microbiology/Microbiology_Laboratory_Manual_(Hartline)/01%3A_Labs/1.03%3A_The_Myth_of_Spontaneous_Ge neration. McLelland CV. 2006. The Nature of Science and the Scientific Method. The Geological Society of America. Moody K, Gonzales A. 2022 Sep 9. 6.2.1: Competitive exclusion principle. Biology LibreTexts. [accessed 2024 Aug 14]. https://bio.libretexts.org/Sandboxes/Team%3A_Ecology_Wildlife_and_Conservation_(EVC)/09%3A_Species_Interactions_in_Communities/9.02%3A_Co mpetitive_Interactions/9.2.01%3A_Competitive_exclusion_principle.