1. Science of Zoology and Evolution of Animal Diversity
Chapter 1
Science of Zoology and Evolution of Animal Diversity
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2. ZOOLOGY—STUDY OF ANIMALS
Life began over 600 million years ago
Evolution of
-multicellularity, coelom, vertebrae, homeothermy

3. 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

4. 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

5. 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

7. 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

8. 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 replicated to produce new genes.
Cells divide producing new cells.
Organisms reproduce, sexually or asexually, to produce new organisms
Populations may fragment to produce new populations
Species may split to produce new species

9. General Properties of Living Systems
Possession of a Genetic Program:
A genetic program provides fidelity of inheritance
DNA: Long, linear, chain of nucleotides containing genetic information
Sequence of nucleotide bases in DNA determines the order of amino acids in proteins
Genetic Code: correspondence between base sequences in DNA and the sequence of amino acids in a protein

11. 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

12. General Properties of Living Systems
Metabolism is often viewed as 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

14. 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

16. 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

18. 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

19. 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

20. 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

21. 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

22. 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

23. 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

24. 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

25. THEORY OF EVOLUTION Charles Darwin and Alfred Wallace
In 1859, Darwin published On the Origin of Species
THEORY OF EVOLUTION

26. Figure 1_05

27. Figure 1_07

28. Theories of Evolution and Heredity
Common Descent
All forms of life descended 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

29. Theories of Evolution and Heredity
Multiplication of Species
The evolutionary process produces new species by splitting and transforming older ones
Gradualism
Large differences in anatomic traits that characterize diverse species originate through the accumulation of many small incremental changes over very long periods of time

31. Theories of Evolution and Heredity
Natural Selection
A creative process that generates novel
forms from the small individual variations that occur among organisms within a population
Adaptation
An anatomical structure, physiological process, or behavioral trait that evolved by natural selection and improves an organism’s ability to survive and leave descendants

32. Theories of Evolution and Heredity
Darwin's theory of natural selection faced a major obstacle when first proposed because it lacked a successful theory of heredity
Neo-Darwinism
Describes Darwin’s theories as modified by incorporating the Chromosomal Theory Of Inheritance

33. Theories of Evolution and Heredity
Mendelian Heredity and the Chromosomal Theory of Inheritance
Foundation for current studies of genetics and evolution in animals
Genetic Approach
Mating populations of organisms that are true-breeding for alternative traits
Following hereditary transmission of those traits to offspring

35. FOSSIL RECORD Hard parts fossilize best
Stratification provides chronological information
FOSSIL RECORD

36. Figure 1_10a

37. Figure 1_10b

38. Figure 1_10c

39. -elaboration of molars
Figure 1_14
Evolution of horses
-increased size
-elaboration of molars
-loss of toes

40. Common descent
Bones of vertebrate limbs
HOMOLOGY

41. Figure 1_16

42. Figure 1_17

43. WHAT IS A SPECIES? Descend from a common ancestor
Exhibit reproductive compatibility
WHAT IS A SPECIES?

44. HOW DO NEW SPECIES APPEAR?
Allopatric speciation
Adaptive radiation
HOW DO NEW SPECIES APPEAR?

46. Figure 1_23a

47. WHEN DOES EVOLUTION OCCUR?
Gradualism v. Punctuated Equilibrium
WHEN DOES EVOLUTION OCCUR?

48. Industrial melanism (dark pigmentation) in peppered moths of England
NATURAL SELECTION

49. Changes in frequencies of variant forms of genes within populations. Ex.-blood type
MICROEVOLUTION

50. Figure 1_31
Selection

51. Population bottleneck
Figure 1_29
Population bottleneck

52. Figure 1_30
Sexual selection