1.0 Introduction

1. The Science of Biology
1. Darwin’s Voyage to South America on HMS Beagle fig 1.1
2. Example of the Exploration of Biology

1. Properties of Life
1. Biologists Study Life in Many Different Ways
2. All Organisms Share Five Basic Characteristics
1. Order: Composed of one or more ordered cells
1. Hierarchical organization fig 1.2
2. Atoms --> molecules --> organelles --> cells --> organs -->organism

2. Sensitivity: Respond to stimuli
3. Growth, development, and reproduction
4. Regulation: Have regulatory mechanisms to coordinate functions
5. Homeostasis: Maintain constant internal conditions

1. The Nature of Science
1. Biology Is Important Subject
1. Knowledge is fundamental to our future
2. Basic tool of a scientist is thought

2. Deductive Reasoning
1. Example: Eratosthenes’ estimation of earth’s circumference fig 1.3
2. Applies general principles to predict specific results
3. Used extensively in math and philosophy

3. Inductive Reasoning
1. Specific observations used to construct general scientific principles
2. Used extensively in and is definition of science
3. Example: Newton and gravity

2. How Science Is Done
1. Scientists establish which principles are true from the many possible
1. Systematically test alternative proposals
2. Construct hypothesis: Suggested explanation for facts
3. Subject to future rejection or alteration

2. Testing Hypotheses
1. Experiment: Tested of a hypothesis fig 1.5
2. Reject those inconsistent with data
3. Conditionally accept those consistent with data
4. New ideas constantly replacing old ones

3. Controls
1. Variables are factors that influence processes
2. Two experiments carried out in parallel
1. In one all variables except one being tested are kept constant
2. In control experiment test variable not changed

3. Differences in parallel experiments attributed to test variable

4. Using Predictions
1. Most useful hypothesis makes predictions
2. Prediction that is rejected may cause rejection of hypothesis
3. Example: Einstein’s hypothesis of relativity
1. Provisionally accepted due to lack of invalidating experiment
2. Light bent in eclipse corroborated prediction, supported hypothesis

5. Developing Theories
1. Theories: Hypotheses that are often tested, never rejected
2. Supported by a great deal of evidence
3. Acceptance most certain, but provisional

6. Research and the Scientific Method
1. Scientific method implied to be logical series of steps
1. Science not truly done this way
2. Scientists construct hypotheses with creative insight

2. Types of scientific research
1. Basic research extends boundaries if scientific knowledge
2. Applied research directed toward scientific industry

3. Scientific work must be communicated via papers in scientific journals

 

1.3 Darwin’s theory of evolution illustrates how science works

1. Darwin’s Theory of Evolution
1. Historical Background
1. Charles Darwin fig 1.5
1. Author of On the Origin of Species
2. Published in 1859 after 30 years of observation

2. Traditional beliefs
1. All organisms resulted from direct actions of a Creator
2. Species unchangeable over course of time

3. Darwin’s alternative
1. Does not support or refute existence of a Creator
2. Natural laws change and improve Creator’s work via evolution

2. Details of Voyage (1831 to 1836)
1. Stops along coasts and islands of southern hemisphere fig 1.6
2. Vessel named H.M.S. Beagle fig 1.7
3. Studied wide variety of plants and animals in many locations

3. Return to England After Voyage
1. Publication of study of life and geology during voyage
2. Forty years of formulation of the evolutionary process

2. Darwin’s Evidence
1. Acceptance of Evolution Inevitable Due to Supporting Evidence
1. New evidence supporting geological events
1. True age of earth greater than a few thousand years
2. Fossil evidence of many unfamiliar species

2. Lyell’s writings on species extinction and emergence

2. What Darwin Saw tbl 1.1
1. Extinct species related to living organisms fig 1.8
2. Characteristics of species varied from place to place
1. Appearance of tortoises dependent on location fig 1.9
2. Slight changes in appearance after island isolation

3. Great variety of organisms on young volcanic islands
1. Resembled forms on mainland, not distant places fig. 1.10
2. Supports evolution, refutes independent creation
3. Inventing the Theory of Natural Selection
1. Darwin and Malthus
1. Malthus wrote Essay on the Principles of Population
1. Populations of organisms increase geometrically fig 1.11
2. Food supply increases arithmetically
3. Unchecked population could reproduce to fill the world
4. Nature acts to check population growth via death

2. Darwin concluded evolution dependent on natural selection

2. Natural Selection
1. Organisms produce more offspring than will survive
2. Surviving organisms are superior in certain attributes fig 1.12
1. Pass these characters to offspring
2. Selection: Changes nature of population as a whole

3. Similar in intent to artificial selection
1. Selection for traits practiced by breeders
2. Animals breed true for traits concentrated in them
3. Example: Domestic pigeons

3. Darwin Drafts His Argument
1. First draft completed in 1842 put away for 16 years
2. May not have wanted to stir up controversy
3. Unlikely that he was refining ideas due to few changes in manuscript

4. Wallace Has Same Ideas
1. Essay from Wallace in 1858
2. Same ideas stimulated completion and presentation

5. Publication of Darwin’s Theory
1. Some views not accepted, suggestion that man evolved from apes fig 1.13
2. Followed by second book further explaining human evolution

4. Evolution After Darwin: Testing the Theory
1. Collection of Evidence by Darwin and Contemporaries
2. The Fossil Record
1. Darwin predicted links between groups of organisms
2. Microscopic fossils 3.5 billion years old
3. Graded series of vertebrate fossils

3. The Age of the Earth
1. In Darwin’s day though to be only a few thousand years old
2. Radioactive decay determined it to be 4.5 billion years,

4. The Mechanism of Heredity
1. Genes unknown at Darwin’s time
2. Laws of inheritance explain genetic variation

5. Comparative Anatomy
1. Comparison of vertebrate forelimb bones fig 1.14
2. Homologous structures: Same origin, different structure and function
3. Analogous structures: Similar structure and function, different origin

6. Molecular Biology
1. Sequence of DNA provides genetic information
2. Construct family trees and estimate rates of evolution
1. Measure degree of change in DNA code
2. Compare to known fossil evidence fig 1.15

7. Development
1. Similarities in developmental stages of species
2. Development (ontogeny) appears to go through stages resembling specie’s evolutionary history (phylogeny)

 

 

1.4 This book is organized to help you learn biology

1. Core Principles of Biology
1. Basic Principles
1. Cell biology: Molecular, subcellular, cellular levels
2. Genetics: Organismal level
3. Evolution: Population level
4. Ecology: Community, global levels

2. Organisms fig 1.16
1. Examination of organisms in second half of text
2. Function of vertebrate body