ASIM'S WEBWORLD View: Main School Main AP Biology Chapter Guides RELATED LINKS Review Questions and Answers		AP BIOLOGY: Chapter One Outline THE SCIENCE OF BIOLOGY Darwin's Voyage to South America on HMS Beagle fig 1.1 Example of the Exploration of Biology BIOLOGY IS THE SCIENCE OF LIFE Biologists Study Life in Many Different Ways Brief Consideration of the Characteristics of Living Things Composed of one or more ordered cells fig 1.2 Hierarchical organization Cells tissues organs systems organism Organism population ecosystem biome biosphere Display sensitivity and respond to stimuli fig 1.3a Capable of growth, development and reproduction fig 1.3b Have regulatory mechanisms to coordinate functions fig 1.3c WHY IS BIOLOGY IMPORTANT TO YOU? Biology Is Interesting Because of Its Great Variety Biology Affects the Quality of Our Future Study population and disease Manage earth's resources Opportunities for Biologists Researchers Genetic engineers Physicians Biology teachers THE NATURE OF SCIENCE Deductive Reasoning Analysis of specific cases using general principles Used extensively in math and philosophy Example: Eratosthenes' estimation of earth's circumference fig 1.4 Inductive Reasoning General principles derived from observations, experiments Used extensively in and is definition of science Example: Newton and gravity Testing Hypotheses fig 1.5 Hypothesis: suggested explanation for facts Subject to future rejection or alteration Tested with observations and experiments Reject those inconsistent with data Conditionally accept those consistent with data Controls Variables are factors that influence processes Two experiments carried out in parallel In one all variables except one being tested are kept constant In control experiment test variable not changed Differences in parallel experiments attributed to test variable The Importance of Prediction Most useful hypothesis makes predictions Prediction that is rejected may cause rejection of hypothesis Example: Einstein's hypothesis of relativity Provisionally accepted due to lack of invalidating experiment Light bent in eclipse corroborated prediction, supported hypothesis Theories Hypotheses that are often tested, never rejected Supported by a great deal of evidence Acceptance most certain, but provisional The Scientific Method Experimental testing of hypothesis Based upon systematic, objective collection of data Hypothesis constructed with creative insight Types of scientific research Basic research extends boundaries if scientific knowledge Applied research directed toward scientific industry Scientific work must be communicated via papers in scientific journals HISTORY OF A BIOLOGICAL THEORY: DARWIN'S THEORY OF EVOLUTION Evolution Provides an Example of the Scientific Process Historical Background Charles Darwin fig 1.6 Author of On the Origin of Species Published in 1859 after 30 years of observation Traditional beliefs All organisms resulted from direct actions of a Creator Species unchangeable over course of time Darwin's alternative Does not support or refute existence of a Creator Natural laws change and improve Creator's work via evolution Details of Voyage (1831 to 1836) Stops along coasts and islands of southern hemisphere fig 1.7 Observations in Patagonia and Galapagos Islands fig 1.8 Return to England After Voyage Publication of study of life and geology during voyage Forty years of formulation of the evolutionary process DARWIN'S EVIDENCE Due to Supporting Evidence Acceptance of Evolution Inevitable Darwin's rejection of supernatural explanations New evidence supporting geological events True age of earth greater than a few thousand years Fossil evidence of many unfamiliar species Lyell's writings on species extinction and emergence What Darwin Saw tbl 1.1 Extinct species related to living organisms fig 1.8 Characteristics of species varied from place to place Appearance of tortoises dependent on location fig 1.9 Slight changes in appearance after island isolation Great variety of organisms on young volcanic islands Resembled forms on mainland, not distant places fig 1.10 Supports evolution, refutes independent creation Darwin and Malthus Malthus wrote Essay on the Principles of Population Populations of organisms increase geometrically fig 1.11 Food supply increases arithmetically Unchecked population could reproduce to fill the world Nature acts to check population growth via death Darwin concluded evolution dependent on natural selection Natural Selection Organisms produce more offspring than will survive Surviving organisms are superior in certain attributes fig 1.12 Pass these characters to offspring Changes nature of population as a whole Similar in intent to artificial selection Selection for traits practiced by breeders Animals breed true for traits concentrated in them Example: domestic pigeons PUBLICATION OF DARWIN'S THEORY First Draft Completed in 1842, Years of Refinement Letter from Wallace with Same Ideas Stimulated Completion and Presentation Some Views Not Accepted, Including Man Evolving From Apes EVOLUTION AFTER DARWIN: TESTING THE THEORY Collection of Evidence by Darwin and Contemporaries The Fossil Record Darwin predicted links between groups of organisms fig 1.13 Microscopic fossils 3.5 billion years old Graded series of vertebrate fossils The Age of the Earth, 4.5 Billion Years, Determined by Radioactive Decay The Mechanisms of Heredity Genes unknown at Darwin's time Laws of inheritance explain genetic variation Comparative Anatomy Comparison of vertebrate forelimb bones fig 1.14 Homologous structures: same origin, different structure and function Analogous structures: similar structure and function, different origin Molecular Biology Sequence of DNA provides genetic information Construct family trees and estimate rates of evolution Measure degree of change in DNA code Compare to known fossil evidence fig 1.15 Development Similarities in developmental stages of species fig 1.16 "Ontogeny recapitulates phylogeny" HOW THIS TEXT IS ORGANIZED TO HELP YOU LEARN BIOLOGY Natural Selection and Evolution Are the Essence of Biology Logical Arrangement of Text Basic principles in first half of text Cell biology: molecular, subcellular, cellular levels Genetics: organismal level Evolution: population level Ecology: community, global levels Examination of organisms in second half of text Microorganisms Plants Animals Function of vertebrate body Chapter information is cumulative