EXPLORING LIFE

1. EXPLORING LIFE

2. What is SCIENCE? • Derived from the Latin verb meaning “to know” • Science is… …a process by which we know and understand how the natural world works • Based on EVIDENCE – limits scientific study to processes that can be observed, measured • Scientific knowledge is PROVISIONAL – evidence we have in front of us whether developed in lab/ observations in nature

3. Is Science ABSOLUTE? • Evidence CAN change! • New tools • New technology • New information • Evidence DOES NOT provide proof or truth (we SUPPORT) • Models approximate the truth and are susceptible to modification • BIAS cannot always be eliminated our “thinking” colors our interpretation

4. How do we obtain our information? Different TYPES of Science • Discovery Science: Describing nature • Hypothesis-based Science: Explaining nature How are they DIFFERENT???

5. Discovery Science Involves careful observation, measurement

6. Hypothesis-based Science

7. Scientific Method provides… Hypothesis Prediction Results in a body of knowledge Experiment Observation Theory (Explanation) Law (Summary)

8. Theory vs. Law • LAW: expresses a FUNDAMENTAL principle of science (“Rule”) • Summarizes the results of repeated observation • MUST be confirmed, agreed upon • Only applies under defined conditions • Does not explain a mechanism Example: Newton's Law of Gravity • THEORY: explains how nature works (“Explains Rules”) • A scientific theory summarizes a hypothesis or group of hypotheses that have been supported with repeated testing, accumulation of extensive, varied evidence • Valid as long as there is no evidence to dispute it. Therefore, theories can be disproven. • Regardless of which definitions one uses, scientists agree that a theory is NOT a “ law in waiting". Theories DO NOT “grow up” to be Laws!

9. The Culture of Science • Scientists build on each other’s work by always remaining skeptical and by seeking reproducible evidence to confirm ideas

10. Science, Technology, & Society • Scientific advances promote new technologies, which in turn enable further scientific advances and useful applications to our lives.

11. The Cell Theory “All life is composed of one or more cells.” • BUT…. What is LIFE?

12. Properties of Life

13. Levels of biological organization (1) (8) (6) (2) (9) (3) (4) (7) (10) (5)

14. Energy flow in an ecosystem

15. DNA: The Genetic Material In each cell, the genes along the length of the DNA molecules encode the information for building the cell’s other molecules. In this way, DNA controls the development and maintenance of the entire organism and, indirectly, everything it does.

16. Prkaryoticvs Eukaryotic Cells

17. What is the importance of Emergent Properties? Characteristics that can be attributed to the arrangement and interactions of parts as complexity increases.

18. Reductionism • Breaking down complex systems to simpler components that are more manageable to study How is this useful in science?

19. Systems Biology • Focuses on how the parts influence one another; results of their interactions Focuses on the parts of the system

20. Form Fits Function Analyzing a biological structure gives us clues about what it does and how it works (FORM) Knowing the function of something provides insight into its construction (FUNCTION)

21. Feedback mechanisms regulate biological systems.

22. Unifying Theme: EVOLUTION • The process of evolution (change over time) is responsible for life’s dual nature of unity and diversity What does this statement mean?

23. Unity in Diversity While a sea horse, a jackrabbit, hummingbird, crocodile and penguin look very different, their skeletons are basically similar. This supports the idea that the organisms living on Earth today are modified descendents of common ancestors.