1. 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
Cilia of windpipe cells
Cilia of Paramecium

2. 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

3. 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

4. The evolutionary view of life came into sharp focus in 1859, when Charles Darwin published On the Origin of Species by Natural Selection

5. 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)

6. Darwin’s Observations
Population
of organisms
Hereditary
variations
Overproduction
and competition
Differences in
reproductive success
Evolution of adaptations
in the population

7. Natural selection can “edit” a population’s heritable variations
LE 1-21a
Natural selection can “edit” a population’s heritable variations
Population with varied inherited traits

8. Elimination of individuals with certain traits
LE 1-21b
Elimination of individuals with certain traits

9. Reproduction of survivors
LE 1-21c
Reproduction of survivors

10. Increasing frequency of traits that enhance
LE 1-21d
Increasing frequency of traits that enhance
survival and reproductive success

11. Bat wings are an example of adaptation
Video: Soaring Hawk

12. South American mainland
The Tree of Life
Large
ground finch
Large cactus
Sharp-beaked
Geospiza
magnirostris
conirostris
Medium
ground
finch
fuliginosa
Small
Woodpecker
Camarhynchus
psittacula
tree finch
Cactus
difficilis
Cactus flower
eaters
scandens
Seed eater
Ground finches
Seed eaters
Tree finches
Common ancestor from
South American mainland
Insect eaters
Bud eater
Warbler finches
Mangrove
fortis
Cactospiza
pallida
pauper
parvulus
Green
warbler
Gray
Certhidea
olivacea
fusca
Vegetarian
Platyspiza
crassirostris
heliobates
Biologists often show evolutionary relationships in a treelike diagram
Phylogenetic Tree

13. Inquiry is a search for information and explanation, often focusing on specific questions
Two main processes of scientific inquiry:
Discovery science: describing nature
Hypothesis-based science: explaining nature

14. Types of Data Two types of data:
Quantitative data: numerical measurements
Qualitative data: recorded descriptions

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

16. 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

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

18. 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

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

20. 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

21. 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

22. Theories in Science
A scientific theory is much broader than a hypothesis
A scientific theory is:
broad in scope
generally enough to generate new hypotheses
supported by a large body of evidence

23. The Culture of Science Science is an intensely social activity
Both cooperation and competition characterize scientific culture

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

25. A set of themes connects the concepts of biology
Science as a Process
Evolution
Energy Transfer
Continuity and Change
Relationship of Structure and Function
Regulation
Interdependence in Nature
Science, Technology, and Society