Chapter 2: Evaluating Scientific Claims PDF

Chapter 2: Evaluating Scientific Claims SCB 101 Professor Calkins Recap: What are they key features of science? Based on the natural world Empirical evidence Testable Falsifiable To Vaccinate or Not The CDC recommends that children receive 10 vaccines, given over a total of 24 doses, between...

Chapter 2: Evaluating Scientific Claims SCB 101 Professor Calkins Recap: What are they key features of science? Based on the natural world Empirical evidence Testable Falsifiable To Vaccinate or Not The CDC recommends that children receive 10 vaccines, given over a total of 24 doses, between birth and 15 months of age. Many mothers were choosing not to vaccinate their children, fearing negative side effects. These claims that vaccines are bad and have negative side effects seem believable…. But are they backed with scientific evidence? How Vaccines Work When the body’s immune system is exposed to a vaccine against a virus (like a flu shot): The immune system recognizes the viral protein as an invader. The immune system mounts an attack against it. Upon later exposure to the actual flu virus: A vaccinated individual’s immune system is already armed and ready to fight before the individual feels sick. The protein itself cannot cause the flu because it does not contain genetic material. It cannot make more copies of the flu virus. How Vaccines Work Recap: Describe in 1-2 sentences how a vaccine creates immunity to a virus. A vaccine contains a harmless form of a virus that is injected into the body. This creates an immune response which ‘teaches’ the body how to react to the virus. If the body is then exposed to the actual virus, then it has already prepared to attack. Recap: Why is it impossible to become infected with a virus from a vaccine composed of viral proteins? Because they don’t contain any genetic material, and therefore can’t reproduce Recap: Natural immunity occurs without a vaccine, just by exposure to a particular stimulus, like the chicken pox virus. Explain why people don’t get chicken pox twice. Because their body remembers how to attack the virus after being exposed only once Vaccines Save Lives Before vaccines, children died in large numbers from: Smallpox Diphtheria Whooping cough Polio Other infectious diseases True or False? Scientists confidently recommended vaccinations. - But media reports and more than 100 mothers on message forums reported children developing autism after being vaccinated. Are anecdotal stories as strong as scientific evidence? Can a new mother afford to take chances?  Evaluating Claims Scientific claim: a statement about how the world works that can be tested using the scientific method Special interest and political groups make unconfirmed claims to further their causes. Claims about global warming, evolution, and medical care are made without the supporting science. We are exposed to ‘scientific claims’ every day, but many come from advertisers, not from scientists themselves. These claims look like science, but they are NOT backed by scientific evidence. This is called pseudoscience. How do we know what is true? Scientific literacy is an understanding of the basics of science and the scientific process. Enables us to make informed decisions about the world around us Enables us to communicate our knowledge to others Credentials, Please Does the entity making the scientific claim have a Ph.D or an MD? Is the degree in the field in which they are making the claim? Is the person affiliated with a major company that has stakes in the claim? Bias: a prejudice or opinion for or against something WHERE is your information coming from? Open-forum sites vs. educational sites Peer reviewed literature vs. media outlets To the Books Primary literature: first publication of scientific research that contains actual data with controls For example: technical reports, conference proceedings, dissertations, peer-reviewed science journals Includes peer review: other scientists checked data and controls before publication was allowed To the Books Secondary literature: sources that give a basic overview of a topic, or summarize research results - For example: textbooks, review articles, popular science journals, respected institutions on the Internet Always check credentials or sources on the Internet. - There must be a reference to a published study in order to be trustworthy. To the Books Social media: Not a good source of scientific information due to a lack of credentials and a lack of peer review by scientists Recap: Why are we less confident of scientific claims made over social media? Because they are most likely not backed by scientific evidence or testing Recap: How does anecdotal evidence differ from scientific evidence? a. It is not composed of systematically collected data or scientific observations and therefore does not give an accurate picture of a subject. b. It does not consist of observations of the natural world. c. It is not published in the news or on the Internet. d. It doesn’t differ enough to be scientifically discounted. Recap: Which of the following is an example of secondary literature? a. Instagram b. Los Angeles Times c. Journal of Medical Microbiology d. The Book of Mormon Correlation ≠ Causation Correlation: two or more aspects of the natural world behave in an interrelated manner Causation: a change in one aspect causes a change in another Correlation does NOT equal causation Meaning, that just because two phenomena occur at the same time, does not mean one is causing the other to happen Recap: The definition of a correlation is a. a statement about how the world works that can be tested using the scientific method. b. research that is intended to expand the fundamental knowledge of science. c. two or more aspects of the natural world that behave in an interrelated manner. d. two or more aspects of the natural world for which a change in one causes a change in another. The Wakefield Study When 8 out of 12 children experienced symptoms of autism after having received an MMR vaccine, more research was needed to determine the cause. Wakefield suggested that the MMR vaccine might be causing autism. Problems with the study: It had only 12 subjects. It did not have a random sample of children. The study had no control group. Its finding could not be replicated. It was NOT scientific or trustworthy. The Wakefield Study The CDC stated that the 20- to 30-fold increase in the incidence of autism since the 1970s is likely due to: - More awareness - More screening for the disease Correlation: two or more aspects of the natural world behave in an interrelated manner - Linking autism to the MMR vaccine is a correlation, NOT a causation. Autism and Organic Foods? Linking autism to the increase in the consumption of organic foods is a correlation, NOT a causation. The Wakefield Study Jain et. Al., 2015: Studied 95,000 children and their siblings and found NO ASSOCIATION between the MMR vaccine and Autism Even though the General Medical Council concluded the Wakefield study was “irresponsible and dishonest,” its conclusions still play a role in forming public opinion. Evaluating Vaccines Recap: What ongoing testing and reporting are vaccines subjected to? Recap: An increase in autism has been shown to occur with an increase in each of the following. Which has been shown to be the actual cause of autism? a. MMR vaccines b. sales of organic foods c. the child reaches the age of 15 months d. All of the above have been shown to cause autism. e. None of the above have been shown to cause autism. Making Choices Herd immunity occurs when a critical portion of a population is vaccinated; then, the spread of disease is contained. Vaccinating a large number of people keeps germs out of circulation and protects the vulnerable members of the community. Recap: Explain why a disease is less likely to spread to vulnerable members of a population if most people are immunized. People with vaccinations drastically reduce the transmission rate of the disease, and because they can’t spread it, it won’t effect as many people Recap: If a mother chooses not to vaccinate her children, who is at risk for contracting and suffering from the disease? a. only her children who are not vaccinated b. she herself, her children, and others in her extended family c. anyone with whom the children come in contact d. any unvaccinated person with whom the children come in contact Homework/ In Class Activity Lab 1: Scientific Method and Scientific Measurements Due MIDNIGHT the night before our next class IF unfinished by class end today STUDY for Quiz 1 Beginning of class next week 20 MC questions, 30 minutes