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EEES 2150- Biodiversity
Biology: Evolution, Diversity, and Ecology
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
PowerPoint Lectures for Biology, Seventh Edition
Neil Campbell and Jane Reece
Lectures by Chris Romero
Chapter 1Chapter 1
Exploring Life
Biology:
The science of life.
Science in the broadest sense refers to any knowledge or trained skill, especially (but not exclusively) when this is attained by verifiable means.[1] The word science also describes any systematic field of study or the knowledge gained from such study. In a more restricted sense, science
refers to a system of acquiring knowledge based on empiricism*, experimentation, and methodological naturalism, as well as to the
organized body of knowledge humans have gained by such research. Scientists maintain that scientific investigation must adhere to the
scientific method, a process for evaluating empirical knowledge which explains observable events in nature as a result of natural causes,
rejecting supernatural notions.
Fields of science are commonly classified along two major lines:Natural sciences, the study of the natural phenomena;
Social sciences, the systematic study of human behavior and society.
*empirical, or empirically based, that is, dependent on evidence or consequences that are observable by the senses
Some Properties of Life
• Order
• Reproduction
• Growth and Development
• Energy Processing/Utilization
• Responsiveness to the Environment
• Regulation & Homeostasis
• Evolutionary Adaptation
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
• Concept 1.1: Biologists explore life from the microscopic to the global scale
• The study of life extends from molecules and cells to the entire living planet
• Biological organization is based on a hierarchy of structural levels
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
A Hierarchy of Biological Organization
1. Biosphere: all environments on Earth
2. Ecosystem: all living and nonliving things in a particular area
3. Community: all organisms in an ecosystem
4. Population: all individuals of a species in a particular area
5. Organism: an individual living thing
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
A Hierarchy of Biological Organization (continued)
6. Organ and organ systems: specialized body parts made up of tissues
7. Tissue: a group of similar cells
8. Cell: life’s fundamental unit of structure and function
9. Organelle: a structural component of a cell
10. Molecule: a chemical structure consisting of atoms
Ecosystems
The biosphere
Organisms
Populations
Communities
Cells
Organelles
Molecules
Tissues
Organs and organ systems
Cell1 µm
Atoms
10 µm
50 µm
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Energy Conversion
• Activities of life require work
• Work depends on sources of energy
• Energy exchange between an organism and environment often involves energy transformations
• In transformations, some energy is lost as heat
• Energy flows through an ecosystem, usually entering as light and exiting as heat
LE 1-4LE 1-4
Sunlight
Ecosystem
Heat
Heat
Chemicalenergy
Consumers(including animals)
Producers(plants and otherphotosynthetic
organisms)
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
A Closer Look at Cells
• The cell is the lowest level of organization that can perform all activities of life
• The ability of cells to divide is the basis of all reproduction, growth, and repair of multicellular organisms
LE 1-5LE 1-5
25 µm
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
The Cell’s Heritable Information
• Cells contain DNA, the heritable information that directs the cell’s activities
• DNA is the substance of genes
• Genes are the units of inheritance that transmit information from parents to offspring
LE 1-6LE 1-6
Sperm cell
NucleicontainingDNA
Egg cell
Fertilized eggwith DNA fromboth parents
Embryo’s cells With copies of inherited DNA
Offspring with traits inherited from both parents
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
• Each DNA molecule is made up of two long chains arranged in a double helix
• Each link of a chain is one of four kinds of chemical building blocks called nucleotides
LE 1-7LE 1-7
DNA double helix Single strand of DNA
Nucleotide
Cell
Nucleus DNA
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Two Main Forms of Cells
• Characteristics shared by all cells:
– Enclosed by a membrane
– Use DNA as genetic information
• Two main forms of cells:
– Eukaryotic: divided into organelles; DNA in nucleus
– Prokaryotic: lack organelles; DNA not separated in a nucleus
LE 1-8LE 1-8
Membrane
Cytoplasm
EUKARYOTIC CELL PROKARYOTIC CELL
DNA(no nucleus)
Membrane
1 µm
Organelles
Nucleus (contains DNA)
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Types of cells- eukaryotes vs. prokaryotes
•Nuclear envelope
•2 or more linear chromosomes
•“Eukaryotic” chromosome proteins & structure
•Membrane-bound organelles
•Asexual reproduction by mitosis
•Sex by fusion of gametes after meiosis
•No nuclear envelope
•One main circular chromosome
•“Prokaryotic” chromosome proteins & structure
•No organelles
•Asexual reproduction by binary fission
•No sexual reproduction
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
• Concept 1.2: Biological systems are much more than the sum of their parts
• A system is a combination of components that form a more complex organization
• Cells, organisms, and ecosystems are some examples of biological systems
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
The Emergent Properties of Systems
• Emergent properties result from arrangements and interactions within systems
• New properties emerge with each step upward in the hierarchy of biological order
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Systems Biology
• Systems biology seeks to create models of the dynamic behavior of whole biological systems
• An example is a systems map of interactions between proteins in a fruit fly cell
• Such models may predict how a change in one part of a system will affect the rest of the system
LE 1-10LE 1-10
CELL
Nucleus
Cytoplasm
Outer membraneand cell surface
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
• Systems biology uses three key research developments:
– High-throughput technology: methods to generate large data sets rapidly
– Bioinformatics: using computers and software to process and integrate large data sets
– Interdisciplinary research teams
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Feedback Regulation in Biological Systems
• Regulatory systems ensure a dynamic balance in living systems
• Chemical processes are catalyzed (accelerated) by enzymes
• Many biological processes are self-regulating: the product regulates the process itself
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
• In negative feedback, the accumulation of a product slows down the process itself
• In positive feedback (less common), the product speeds up its own production
Animation: Negative Feedback Animation: Positive Feedback
LE 1-11LE 1-11
Enzyme 1
A A
BB
C C
DD
D
DD
D
D
D
DDD
Enzyme 2
Enzyme 3
Negativefeedback
Enzyme 1
LE 1-12LE 1-12
W
Enzyme 4
W
XX
Y Y
ZZ
ZZ
Z ZZ
ZZ Z
Enzyme 5
Enzyme 6
Positivefeedback
Enzyme 4
Enzyme 6
Enzyme 5
Z
Z Z Z
Z
Z
Z
ZZ
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
• Concept 1.3: Biologists explore life across its great diversity of species
• Biologists have named about 1.8 million species
• Estimates of total species range from 10 million to over 200 million
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Grouping Species: The Basic Idea
• Taxonomy is the branch of biology that names and classifies species into a hierarchical order
• Kingdoms and domains are the broadest units of classification
LE 1-14LE 1-14
Ursidae
Ursus
Carnivora
Mammalia
Chordata
Animalia
Eukarya
Species Genus Family Order Class Phylum Kingdom DomainUrsusamericanus(Americanblack bear)
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
The Three Domains of Life
• At the highest level, life is classified into three domains:
– Bacteria (prokaryotes)
– Archaea (prokaryotes)
– Eukarya (eukaryotes)Eukaryotes include protists and the kingdoms Plantae, Fungi, and Animalia
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Figure 27.1 The three major lineages of life
LE 1-15LE 1-15
Bacteria 4 µm 100 µm
0.5 µm
Kingdom PlantaeProtists
Kingdom AnimaliaKingdom FungiArchaea
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Unity in the Diversity of Life
• Underlying life’s diversity is a striking unity, especially at lower levels of organization
• In eukaryotes, unity is evident in details of cell structure
LE 1-16aLE 1-16a
Cilia of windpipe cellsCilia of Paramecium
15 µm 5 µm
LE 1-16bLE 1-16b
Cilia of windpipe cellsCilia of Paramecium
Cross section of cilium,as viewed with anelectron microscope
0.1 µm
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
• Concept 1.4: Evolution accounts for life’s unity and diversity
• The history of life is a saga of a changing Earth billions of years old
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Fig. 16.4
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
• The evolutionary view of life came into sharp focus in 1859, when Charles Darwin published On the Origin of Species by Natural Selection
• “Darwinism” became almost synonymous with the concept of evolution
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
• The Origin of Species articulated two main points:
– Descent with modification (the view that contemporary species arose from a succession of ancestors)
– Natural selection (a proposed mechanism for descent with modification)
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Descent with modification
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Natural Selection
• Darwin inferred natural selection by connecting two observations:
– Observation: Individual variation in heritable traits
– Observation: Overpopulation and competition
– Inference: Unequal reproductive success
– Inference: Evolutionary adaptation
LE 1-20LE 1-20
Evolution of adaptationsin the population
Differences inreproductive success
Overproductionand competition
Populationof organisms
Hereditaryvariations
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Theory of Natural Selection
• Over-reproduction
• Struggle for existence
• Survival & reproduction of the fittest
• Inheritance & accumulation of favorable traits
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
• Natural selection can “edit” a population’s heritable variations
• An example is the effect of birds preying on a beetle population
LE 1-21LE 1-21
Population with varied inherited traits
Elimination of individuals with certain traits
Reproduction of survivors
Increasing frequency of traits that enhancesurvival and reproductive success
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
• Natural selection is often evident in adaptations of organisms to their way of life and environment
• Bat wings are an example of adaptation
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Evolutionary adaptation is a product of natural selection
Seahorse Poorwill
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
The Tree of Life
• Many related organisms have similar features adapted for specific ways of life
• Such kinships connect life’s unity and diversity to descent with modification
• Natural selection eventually produces new species from ancestral species
• Biologists often show evolutionary relationships in a treelike diagram
LE 1-23LE 1-23Largeground finch
Large cactusground finch
Sharp-beakedground finch
Geospizamagnirostris
Geospizaconirostris
Mediumground finch
Geospizafuliginosa
Smallground finch
Woodpecker finch
Camarhynchuspsittacula
Large tree finch
Medium tree finch
Cactusground finch
Geospizadifficilis
Cactus flowereaters
Geospizascandens
Seed eater
Ground finches
Seed eaters
Tree finches
Common ancestor fromSouth American mainland
Insect eaters Bud eater
Warbler finches
Mangrove finchGeospiza
fortis
Cactospizapallida Small
tree finch
Camarhynchuspauper
Camarhynchusparvulus
Greenwarblerfinch
Graywarblerfinch
Certhideaolivacea
Certhideafusca
Vegetarianfinch
Platyspizacrassirostris
Cactospizaheliobates
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
• Concept 1.5: Biologists use various forms of inquiry to explore life
• Inquiry is a search for information and explanation, often focusing on specific questions
• The process of science blends two main processes of scientific inquiry:
– Discovery science: describing nature
– Hypothesis-based science: explaining nature
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Discovery Science
• Discovery science describes nature through careful observation and data analysis
• Examples of discovery science:
– understanding cell structure
– expanding databases of genomes
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Types of Data
• Data are recorded observations
• Two types of data:
– Quantitative data: numerical measurements
– Qualitative data: recorded descriptions
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Induction in Discovery Science
• Inductive reasoning involves generalizing based on many specific observations
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Hypothesis-Based Science
• In science, inquiry usually involves proposing and testing hypotheses
• Hypotheses are hypothetical explanations
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
The Role of Hypotheses in Inquiry
• In science, a hypothesis is a tentative answer to a well-framed question
• A hypothesis is an explanation on trial, making a prediction that can be tested
LE 1-25aLE 1-25a
Hypothesis #1:Dead batteries
Hypothesis #2:Burnt-out bulb
Observations
Question
LE 1-25bLE 1-25b
Hypothesis #1:Dead batteries
Hypothesis #2:Burnt-out bulb
Test prediction
Test falsifies hypothesis
Prediction:Replacing batterieswill fix problem
Prediction:Replacing bulbwill fix problem
Test prediction
Test does not falsify hypothesis
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Deduction: The “If…then” Logic of Hypothesis-Based Science
• In deductive reasoning, the logic flows from the general to the specific
• If a hypothesis is correct, then we can expect a particular outcome
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
A Closer Look at Hypotheses in Scientific Inquiry
• A scientific hypothesis must have two important qualities:
– It must be testable
– It must be falsifiable
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
The Myth of the Scientific Method
• The scientific method is an idealized process of inquiry
• Very few scientific inquiries adhere rigidly to the “textbook” scientific method
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Designing Controlled Experiments
• Scientists do not control the experimental environment by keeping all variables constant
• Researchers usually “control” unwanted variables by using control groups to cancel their effects
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Limitations of Science
• The limitations of science are set by its naturalism
– Science seeks natural causes for natural phenomena
– Science cannot support or falsify supernatural explanations, which are outside the bounds of science
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Theories in Science
• A scientific theory is much broader than a hypothesis
• A scientific theory is:
– broad in scope
– general enough to generate new hypotheses
– supported by a large body of evidence
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Model Building in Science
• Models are representations of ideas, structures, or processes
• Models may range from lifelike representations to symbolic schematics
LE 1-30LE 1-30Frombody
Fromlungs
Rightatrium
Leftatrium
Rightventricle
Leftventricle
To lungs To body
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Science, Technology, and Society
• The goal of science is to understand natural phenomena
• Technology applies scientific knowledge for some specific purpose
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
• Concept 1.6: A set of themes connects the concepts of biology
• Biology is the science most connected to the humanities and social sciences
• Underlying themes provide a framework for understanding biology
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Structure and function are correlated
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings