Integrated Principles of Zoology, 15/e Cleveland P. Hickman, Jr. Allan Larson David Eisenhour

1. Integrated Principles of Zoology, 15/e Cleveland  P. Hickman, Jr. Allan Larson David Eisenhour 1-1

2. CHAPTER 1 Life: Biological Principles and the Science of Zoology 1-2

4. The Uses of Principles • Zoology: The scientific study of animal life • Exploration of the animal world is gained by actively applying important guiding principles to our investigations • Exploration of the animal world depends critically on our questions, methods, and principles

5. The Uses of Principles • Principles of modern zoology come from: • Laws of physics and chemistry • Scientific method • Because life shares a common evolutionary origin, principles learned from the study of one group often provide insight to other groups as well

6. Fundamental Properties of Life • Does Life Have Defining Properties? • What is life? • No simple definition • The history of life shows extensive and ongoing change called evolution • Answer must be based on the common history of life on earth

7. Fundamental Properties of Life • This common history can be traced backward through time from the diverse forms observed today and in the fossil record to their common ancestor that arose almost five billion years ago • Life's history of descent with modification gives it an identity and continuity that separates it from the nonliving world

8. General Properties of Living Systems • Chemical Uniqueness: Living systems demonstrate a unique and complex molecular organization • Small molecules are assembled into macromolecules: • Nucleic Acids • Proteins • Carbohydrates • Lipids

9. General Properties of Living Systems • Although living systems are composed of the same kinds of atoms obeying the same fundamental laws of chemistry as nonliving matter, the organizational structure of the macromolecules makes them unique

11. General Properties of Living Systems • Complexity and Hierarchical Organization: Living systems demonstrate a unique and complex hierarchical organization • In living systems there exists a hierarchy of levels that includes: Macromolecules Cells Organisms Populations Species

14. General Properties of Living Systems • Emergence: A appearance of new characteristics at a given level of organization • These characteristics are called emergent properties • Different levels of the biological hierarchy and their particular emergent properties are built by evolution

16. General Properties of Living Systems • Reproduction: Living systems can reproduce themselves • At each level of the biological hierarchy living forms reproduce to generate others like themselves: • Genes replicate to produce new genes. • Cells divide producing new cells. • Organisms reproduce, sexually or asexually, to produce new organisms • Populations fragment to produce new populations • Species split to produce new species

18. General Properties of Living Systems • Possession of a Genetic Program: A genetic program provides fidelity of inheritance • Nucleic Acids: Encode structures of the protein molecules needed for organismal development and functioning • DNA: Long, linear, chain of nucleotides • Stores genetic information • Genetic Code: correspondence between base sequences in DNA and the sequence of amino acids in a protein

20. General Properties of Living Systems • Metabolism: Living organisms maintain themselves by acquiring nutrients from their environments • Metabolic processes include: • Digestion • Energy production (Respiration) • Synthesis of required molecules and structures by organisms

21. General Properties of Living Systems • Metabolism is an interaction of destructive (catabolic) and constructive (anabolic) reactions • The most fundamental anabolic and catabolic chemical processes used by living systems arose early in the evolutionary history of life

23. General Properties of Living Systems • Development: All organisms pass through a characteristic life cycle • Development describes the characteristic changes that an organism undergoes from its origin to its final adult form

25. General Properties of Living Systems • Environmental Interaction: All animals interact with their environments • Ecology: The study of organismal interaction with an environment • All organisms respond to environmental stimuli, a property called irritability

27. General Properties of Living Systems • Movement: Living systems and their parts show precise and controlled movements arising from within the system • Living systems extract energy from their environments permitting the initiation of controlled movements

28. General Properties of Living Systems • Movements at the cellular level are required for: Reproduction Growth Responses to stimuli Development in multicellular organisms • On a larger scale: Entire populations or species may disperse from one geographic location to another over time • Movement of nonliving matter: • Not precisely controlled by the moving objects • Often involves external forces

29. Life Obeys Physical Laws • First Law of Thermodynamics (Law of Conservation of energy): Energy is neither created nor destroyed but can be transformed from one form to another • All aspects of life require energy and its transformation

30. Life Obeys Physical Laws • Second Law of Thermodynamics Physical systems tend to proceed toward a state of greater disorder or entropy • The ultimate fate of materials in cells is degradation and dissipation of their chemical bond energy as heat • Organismal complexity is achieved and maintained only by the perpetual use and dissipation of energy flowing into the biosphere from the sun

31. Life Obeys Physical Laws • The complex molecular organization in living cells is attained and maintained only as long as energy fuels the organization • Survival, growth, and reproduction of animals require energy that comes from breaking complex food molecules into simple organic waste

32. Zoology As Part of Biology • Animals originated in the Precambrian seas over 600 million years ago • Characteristics of Animals: • Eukaryotes: cells contain membrane-enclosed nuclei • Heterotrophs: Not capable of manufacturing their own food and must rely on external food sources • Cells lack cell walls

34. Principles of Science • Nature of science: • Science is guided by natural law • Science has to be explained by reference to natural law • Science is testable against the observable world • The conclusions of science are tentative and therefore not necessarily the final word • Science is falsifiable

35. Principles of Science • Scientific Method • Hypothetic-deductive Method: Scientific process of making a conjecture and then seeking empirical tests that potentially lead to its rejection

36. Principles of Science • Hypothesis: • Potential answers to questions being asked • Derived from prior observations of nature or from theories based on such observations • Often constitute general statements about nature that may explain a large number of diverse observations • If a hypothesis is very powerful in explaining a wide variety of related phenomena, it attains the level of a theory

37. Principles of Science The scientific method may be summarized as a series of steps: Observation Question Hypothesis Formation Empirical Test Controlled Experiment Includes at least 2 groups Test Group Control Group Conclusions Accept or reject your hypothesis Publications 1-37

39. Principles of Science • Powerful theories that guide extensive research are called paradigms • The refutement and replacement of a paradigm is known as a scientific revolution • Two major paradigms that guide zoological research: • Darwin’s Theory of Evolution • The Chromosomal Theory of Inheritance

40. Principles of Science • Experimental vs. Evolutionary Sciences • Experimental Sciences: • Seek to explain the proximate or immediate causes that underlie the functioning of biological systems at a particular time and place • Goal: To explain how animals perform metabolic, physiological, and behavioral functions at the molecular, cellular, organismal, and populational levels

41. Principles of Science • Example: • How is genetic information expressed to guide the synthesis of proteins? • What signal causes cells to divide to produce new cells? • How does population density affect the physiology and behavior of organisms? • Experimental Sciences: Molecular Biology, Cell Biology, Endocrinology, Developmental Biology Community Ecology

42. Principles of Science • Evolutionary Sciences: • Seek to address questions of ultimate causes and rely largely on the use of the comparative method rather than experimentation • Ultimate Cause: The evolutionary factors responsible for the origin, state of being, or purpose of a biological system

43. Principles of Science • Molecular biology, cell biology, organismal structure, development, and ecology are compared among related species to identify patterns of variation • Patterns of similarity and dissimilarity are used to test hypotheses of relatedness • This information is used to reconstruct the evolutionary tree that relates to the species being studied • Rely on experimental sciences as a starting point

44. Principles of Science • Example: • Why do different species of animals have different numbers of chromosomes in their cells? • Why do some animal species maintain complex social systems, whereas other species have solitary individuals? • Evolutionary Sciences: Comparative Biochemistry, Molecular Evolution, Comparative Cell Biology, Comparative Anatomy, Comparative Physiology, and Phylogenetic Systematics

45. Theories of Evolution and Heredity • Darwin’s Theory of Evolution • Over 150 years old • Published in On the Origin of Species by Means of Natural Selection in England in 1859 • Darwinism encompasses several different, although mutually compatible theories

46. Theories of Evolution and Heredity • Ernst Mayr (Harvard University) proposed that Darwinism should be viewed as five major theories: • Perpetual Change • Common Descent • Multiplication of the Species • Gradualism • Natural Selection

48. Theories of Evolution and Heredity • Perpetual Change The living world is neither constant nor perpetually cycling, but is always changing • The varying forms of organisms undergo measurable change across generations throughout time • Documented by the fossil record • Theory upon which the remaining 4 are based

49. Theories of Evolution and Heredity • Common Descent All forms of life descend from a common ancestor through a branching of lineages • Life’s history has the structure of a branching evolutionary tree, known as a phylogeny • Serves as the basis for our taxonomic classification of animals