Transcript Lecture 1

Chapter 1
Science of
Zoology and
Evolution of
Animal
Diversity
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
ZOOLOGY—STUDY OF ANIMALS
Life began over 600 million years ago
Evolution of
-multicellularity, coelom, vertebrae, homeothermy
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
1-3
General Properties of Living Systems
• Chemical Uniqueness:
Living systems demonstrate a unique and
complex molecular organization
– Small molecules are assembled into
macromolecules:
1. Nucleic Acids
2. Proteins
3. Carbohydrates
4. Lipids
1-4
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
1-5
1-6
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
1-7
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

1-8
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
1-9
1-10
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
1-11
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
1-12
1-13
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
1-14
1-15
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
1-16
1-17
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
1-18
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
1-19
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
1-20
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
1-21
•
Principles of Science
The scientific method may be summarized as
a series of steps:
1.
2.
3.
4.
Observation
Question
Hypothesis Formation
Empirical Test
– Controlled Experiment
Includes at least 2 groups
Test Group
Control Group
5. Conclusions
Accept or reject your hypothesis
6. Publications
1-22
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
1-23
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:
1. Darwin’s Theory of Evolution
2. The Chromosomal Theory of Inheritance
1-24
Charles Darwin and Alfred Wallace
In 1859, Darwin published On the Origin of Species
THEORY OF EVOLUTION
Figure 1_05
Figure 1_07
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
1-28
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
1-29
1-30
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
1-31
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
1-32
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
1-33
1-34
Hard parts fossilize best
Stratification provides chronological information
FOSSIL RECORD
Figure 1_10a
Figure 1_10b
Figure 1_10c
Figure 1_14
Evolution of
horses
-increased
size
-elaboration
of molars
-loss of toes
Common descent
Bones of vertebrate limbs
HOMOLOGY
Figure 1_16
Figure 1_17
1) Descend from a common ancestor
2) Exhibit reproductive compatibility
WHAT IS A SPECIES?
Allopatric speciation
Adaptive radiation
HOW DO NEW SPECIES APPEAR?
1-45
Figure 1_23a
Gradualism v. Punctuated Equilibrium
WHEN DOES EVOLUTION OCCUR?
Industrial melanism (dark pigmentation) in peppered moths of England
NATURAL SELECTION
Changes in frequencies of variant forms of genes within populations. Ex.blood type
MICROEVOLUTION
Figure 1_31
Selection
Figure 1_29
Population bottleneck
Figure 1_30
Sexual selection