The Characteristics of LifeHow are living things different from nonliving things?Living things:Require energy and raw materialsAre composed of cellsMaintain homeostasisRespond to environmentGrow and reproduceAre capable of evolvingSlide 1.1

A Five-Kingdom ClassificationMonera:single-celled prokaryotesAnimalia:eukaryotic animals, heterotrophsPlantae:eukaryotic, photosynthetic plantsFungi:eukaryotic, decomposers (fungi, yeast, mushrooms)Protista: eukaryotic protoza, algae, slimemolds

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Principles of EvolutionDarwins Principles of Natural Selection Know these four observations of Darwin in his book Origin of the Species, 1859 One: Individual members of a species show variation from one another. They are born with these variations (just think of how a litter of puppies vary, one is the runt, one is the most intelligent, etc.) Two: Organisms produce many more offspring than will survive to reproduce. Three: This sets up a competition for resources like food. Individuals born with variations that give them some advantage over others are more likely to survive. Four: The survivors live to reproduce and pass their adaptations for survival to their offspring. This results in individuals more adapted to their environment: the principle of adaptation The environment selects the best adapted individuals for survival: the principle of natural selection.

Homeostasis The most important principle of human biology Name literally means same staying Mechanism to balance body systems Example: When we are hot, the increased temperature is noticed by the hypothalamus (part of brain), it sends signals to the sweat glands to sweat and the blood vessels to dilate. Result: body temp. comes down.

Homeostasis, cont. This is an example of a NEGATIVE FEEDBACK system. The things that happen are opposite to the present conditions i.e. the sweat glands were producing sweat and the negative feedback is to turn them off Later in the course we will see examples of POSITIVE FEEDBACK Why is homeostasis so important? It explains and allows us to understand disease and health. When the homeostasis mechanism is disrupted, it causes problems Start to think homeostatically for the rest of the course. Ask yourself questions like, What would happen if this part of the homeostatic mechanism was disrupted? Are there other homeostatic mechanisms that would step in to help return the body to a state of health?

Defining Features of HumansBipedalism- but other primates do this sometime

Opposable thumbs- other primates have this, too.

Large brain- so do marine mammals

Capacity for language- other primates, too and whales & dolphins use languageCapacity for culture (sets us apart from all other organisms

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Levels of Biological OrganizationAtom and moleculeCellTissueOrganOrgan system

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Levels of Biological Organization (cont.)

Figure 1.7Slide 1.4 B

Levels of Biological Organization (cont.)OrganismPopulationCommunityEcosystemBiosphere

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Levels of Biological Organization (cont.)

Figure 1.7 cont.Slide 1.5 B

The Scientific Method

Figure 1.8Slide 1.6

Steps in the Scientific MethodObserve and generalizeFormulate a hypothesisMake a testable predictionExperiment or observeModify the hypothesis as necessary and repeat

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Ways to Disseminate FindingsPeer-reviewed journals

Popular press

Electronic publications

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Hypothesis vs. TheoryBe broadBe extensively testedBe supported over timeExplain a broad range of factsHave a high degree of reliability

Slide 1.9For a hypothesis to become a theory it must:Theories may be refuted in the future

Learning to be a Critical ThinkerBecome a skepticAppreciate the value of statisticsLearn to read graphsDistinguish anecdotes from scientific evidenceSeparate facts from conclusionsUnderstand the differences between correlation and causation

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The Role of Science in SocietyScience improves technology and the human condition

Science has limits

Making informed choices

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