The Science of Biology Chapter 2

What is Science?? Science (“to know”) is a way to ask questions about the natural world Science is testable or falsifiable; beliefs, opinions, and the supernatural are not testable Science is supported with evidence that can be verified through repeated experiments

What is Science?? (continued) Science is NOT a set of unchanging facts; it is an ongoing process that advances knowledge and understanding Scientific knowledge is uncertain Reality is complex Explanations of reality are not absolutely true Allows for alternative explanations to better explain observations Scientists must be skeptical (question existing ideas) and open-minded (consider new hypotheses if the data supports it)

Discovery Science Describes natural structures or processes through careful observation and data collection Emphasizes inquiry and observation Inquiry is about asking questions based on observations and actively seeking answers Observation is the use of the senses or instruments to gather and record information about structures or processes Observations are recorded as Data

Types of Data QUANTITATIVE A recorded measurement Scientists worldwide use the metric system QUALITATIVE Descriptions, drawings, or photographs Best data is documented, clearly organized, consistently recorded, and reliable

Inferences Logical conclusions based on observations Example: In 1928, Alexander Fleming observed a mold contaminating a cultured of bacteria. He noticed no bacteria growing near the mold. He inferred that the mold was killing the bacteria.

Practice making Inferences…

Inferences and Generalizations in Science Inferences help refine general questions into specific questions that can be explored further Ex: What substance produced by this mold is killing the bacteria? Generalizations are conclusions formed from many specific observations that are related Ex: Many molds have antibiotic properties that can be used to kill bacteria harmful to humans.

Hypothesis-based Science Seeks explanations to specific questions by testing predictions Ex: Poisonous snakes have bright colors and rings. Some non-poisonous snakes also have bright colors and rings. Question: What is the function of such mimicry? POISONOUS NON-POISONOUS

Form a Hypothesis Hypothesis: Mimics benefit because predators confuse them with the harmful species. Restate the hypothesis in “IF, AND, and THEN” format: If this idea is true, and I do this, then this will happen. EX: If predators confuse the mimics with the harmful species, and I expose predators to non-poisonous snakes with rings and without rings, then the predators will attack the species without the rings more often.

Design a Controlled Experiment The experiment is designed to test the hypothesis Can only test the effect of ONE variable!! Ex: The presence of colored rings on the snakes body The Control Group The Experimental Group

Organize Data and Interpret Results Quantitative data should be organized into charts and graphs The results will either support the hypothesis or cause the scientist to revise his or her hypothesis and test again

Theories in Science A theory is a well-tested explanation that makes sense out of a great variety of scientific observations Supported by an extensive body of evidence Provide framework for future research and predictions Subject to modification as new evidence is uncovered

Models in Science Models are physical, mental, or mathematical representations of how to understand a process or an idea Can be drawings, graphs, 3D, computer programs, or equations

Communication and Technology in Science Communication is necessary for cooperation and competition among scientists Scientist communicate their ideas in published journals and the web Technology is the result of applied scientific understanding Ex: Structure of DNA = Science Genetic Engineering = Technology

Science, Technology, and Society Technology is not driven by the curiosity that drives basic science, but by the needs and wants of humans Ethics in Science: Debated issues about technology ask “should it be done,” not “can it be done” Good citizens make an effort to understand the technology before making lifestyle and democratic choices