1. Biology: Evolution, Diversity, and Ecology
EEES Biodiversity
Biology: Evolution, Diversity, and Ecology

2. Chapter 1
Exploring Life

3. Biology:
The science of life.

4. 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

5. Some Properties of Life
Order
Reproduction
Growth and Development
Energy Processing/Utilization
Responsiveness to the Environment
Regulation & Homeostasis
Evolutionary Adaptation

7. 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

8. A Hierarchy of Biological Organization
Biosphere: all environments on Earth
Ecosystem: all living and nonliving things in a particular area
Community: all organisms in an ecosystem
Population: all individuals of a species in a particular area
Organism: an individual living thing

9. A Hierarchy of Biological Organization (continued)
Organ and organ systems: specialized body parts made up of tissues
Tissue: a group of similar cells
Cell: life’s fundamental unit of structure and function
Organelle: a structural component of a cell
Molecule: a chemical structure consisting of atoms

10. Organs and organ systems Organisms
The biosphere
Organelles
1 µm
Cell
Ecosystems
Cells
Atoms
Molecules
10 µm
Communities
Tissues
50 µm
Populations
Organs and organ systems
Organisms

11. 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

12. LE 1-4 Sunlight Ecosystem Producers (plants and other photosynthetic
organisms)
Heat
Chemical
energy
Consumers
(including animals)
Heat

13. 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

14. LE 1-5
25 µm

15. 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

16. LE 1-6 Sperm cell Nuclei containing DNA Fertilized egg Embryo’s cells
with DNA from
both parents
Embryo’s cells
With copies of
inherited DNA
Egg cell
Offspring with traits
inherited from both parents

17. 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

18. Nucleus DNA Nucleotide Cell DNA double helix Single strand of DNA

19. 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

20. LE 1-8
EUKARYOTIC CELL
PROKARYOTIC CELL
DNA
(no nucleus)
Membrane
Membrane
Cytoplasm
Organelles
Nucleus (contains DNA)
1 µm

21. 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

25. Plant and animal cells larger than bacteria and viruses (require microscope)

26. 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

27. 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

28. 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

29. LE 1-10
Outer membrane
and cell surface
CELL
Cytoplasm
Nucleus

30. 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

31. 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

32. Animation: Negative Feedback Animation: Positive Feedback
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

33. A A Negative feedback Enzyme 1 Enzyme 1 B B Enzyme 2 C C Enzyme 3 D D
LE 1-11 A A
Negative
feedback
Enzyme 1
Enzyme 1 B B
Enzyme 2 C C
Enzyme 3 D D D D D D D D D D D

34. W W Enzyme 4 Enzyme 4 X X Positive feedback Enzyme 5 Enzyme 5 Y Y
LE 1-12 W W
Enzyme 4
Enzyme 4 X X
Positive
feedback
Enzyme 5
Enzyme 5 Y Y
Enzyme 6
Enzyme 6 Z Z Z Z Z Z Z Z Z Z Z Z Z Z Z Z Z Z Z

35. 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

37. 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

38. LE 1-14
Species
Genus
Family
Order
Class
Phylum
Kingdom
Domain
Ursus
americanus
(American
black bear)
Ursus
Ursidae
Carnivora
Mammalia
Chordata
Animalia
Eukarya

39. 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

40. Figure 27.1 The three major lineages of life

41. LE 1-15 Bacteria Protists Kingdom Plantae Archaea Kingdom Fungi
Kingdom Animalia

42. 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

43. Cilia of windpipe cells
LE 1-16a
15 µm
5 µm
Cilia of Paramecium
Cilia of windpipe cells

44. Cross section of cilium, as viewed with an electron microscope
LE 1-16b
0.1 µm
Cross section of cilium,
as viewed with an
electron microscope
Cilia of Paramecium
Cilia of windpipe cells

45. 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

48. Fig. 16.4

49. 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

51. 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)

52. Descent with modification

53. 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

54. LE 1-20 Population of organisms Hereditary Overproduction variations
and competition
Differences in
reproductive success
Evolution of adaptations
in the population

55. Theory of Natural Selection
Over-reproduction
Struggle for existence
Survival & reproduction of the fittest
Inheritance & accumulation of favorable traits

56. Natural selection can “edit” a population’s heritable variations
An example is the effect of birds preying on a beetle population

57. LE 1-21 Population with varied inherited traits
Elimination of individuals with certain traits
Reproduction of survivors
Increasing frequency of traits that enhance
survival and reproductive success

58. Natural selection is often evident in adaptations of organisms to their way of life and environment
Bat wings are an example of adaptation

60. Evolutionary adaptation is a product of natural selection
Seahorse
Poorwill

61. 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

62. South American mainland
LE 1-23
Large
ground finch
Large
tree finch
Small
ground
finch
Large cactus
ground finch
Camarhynchus
psittacula
Geospiza
magnirostris
Geospiza
fuliginosa
Green
warbler
finch
Gray
warbler
finch
Sharp-beaked
ground finch
Woodpecker
finch
Medium
tree finch
Geospiza
conirostris
Medium
ground
finch
Certhidea
olivacea
Certhidea
fusca
Geospiza
difficilis
Cactus
ground finch
Camarhynchus
pauper
Cactospiza
pallida
Small
tree finch
Mangrove
finch
Geospiza
fortis
Geospiza
scandens
Camarhynchus
parvulus
Cactospiza
heliobates
Seed eater
Vegetarian
finch
Cactus flower
eaters
Seed eaters
Platyspiza
crassirostris
Insect eaters
Bud eater
Ground finches
Tree finches
Warbler finches
Common ancestor from
South American mainland

63. 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

64. Discovery Science
Discovery science describes nature through careful observation and data analysis
Examples of discovery science:
understanding cell structure
expanding databases of genomes

65. Types of Data Data are recorded observations Two types of data:
Quantitative data: numerical measurements
Qualitative data: recorded descriptions

67. Induction in Discovery Science
Inductive reasoning involves generalizing based on many specific observations

68. Hypothesis-Based Science
In science, inquiry usually involves proposing and testing hypotheses
Hypotheses are hypothetical explanations

69. 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

70. Observations Question Hypothesis #1: Dead batteries Hypothesis #2:
LE 1-25a
Observations
Question
Hypothesis #1:
Dead batteries
Hypothesis #2:
Burnt-out bulb

71. Test falsifies hypothesis Test does not falsify hypothesis
LE 1-25b
Hypothesis #1:
Dead batteries
Hypothesis #2:
Burnt-out bulb
Prediction:
Replacing batteries
will fix problem
Prediction:
Replacing bulb
will fix problem
Test prediction
Test prediction
Test falsifies hypothesis
Test does not falsify hypothesis

72. 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

73. A Closer Look at Hypotheses in Scientific Inquiry
A scientific hypothesis must have two important qualities:
It must be testable
It must be falsifiable

74. 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

75. 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

76. 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

77. 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

78. Model Building in Science
Models are representations of ideas, structures, or processes
Models may range from lifelike representations to symbolic schematics

79. From body From lungs Right atrium Left atrium Right ventricle Left
To lungs
To body

80. Science, Technology, and Society
The goal of science is to understand natural phenomena
Technology applies scientific knowledge for some specific purpose

81. 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

90. Structure and function are correlated