Part 2

Figure 1.6-7
Kingdom Animalia
© 2016 Pearson Education, Ltd.

1.7 Evolution explains the unity and
diversity of life
• Evolution can be defined as the process of
change that has transformed life on Earth
from its earliest beginnings to the diversity of
organisms living today.
• The fossil record documents
– that life has been evolving on Earth for billions of
years and
– the pattern of ancestry.

Figure 1.7a

1.7 Evolution explains the unity and
diversity of life
• In 1859, Charles Darwin published the book
On the Origin of Species by Means of Natural
Selection, which articulated two main points.
1. Species living today descended from ancestral
species in what Darwin called “descent with
modification.”
2. Natural selection is a mechanism for evolution.

Video: Galápagos Island Overview

Video: Galápagos Marine Iguana

Video: Galápagos Sea Lion

Video: Galápagos Tortoise

Figure 1.7b

Figure 1.7c-0

Figure 1.7c-1

Figure 1.7c-2

Figure 1.7c-3

1.7 Evolution explains the unity
and diversity of life
• Natural selection was inferred by connecting
two observations.
1. Individual variation: Individuals in a population
vary in their traits, many of which are passed
on from parents to offspring.
2. Overproduction of offspring: A population can
produce far more offspring than the
environment
can support.

Video: Blue-footed Boobies
Courtship Ritual

Video: Albatross Courtship Ritual

Video: Soaring Hawk

• From these observations, Darwin drew two
inferences.
1. Unequal reproductive success: Individuals with
heritable traits best suited to the environment
are more likely to survive and reproduce than
less well-suited individuals.
2. Accumulation of favorable traits over time: As a
result of this unequal reproductive success over
many generations, an increasing proportion of
individuals in a population will have the
advantageous traits.© 2016 Pearson Education, Ltd.

Figure 1.7d-1
Population with varied
inherited traits.
1

Figure 1.7d-2
inherited traits.
1 2 Elimination of
individuals with certain
traits and reproduction
of survivors.

Figure 1.7d-3
inherited traits.
1 2 3Elimination of
individuals with certain
traits and reproduction
of survivors.
Increasing frequency
of traits that enhance
survival and
reproductive success.

• Darwin realized that numerous small changes
in populations as a result of natural selection
could eventually lead to major alterations of
species.
• The fossil record provides evidence of such
diversification of species from ancestral
species.

Figure 1.7e-0
Millions of
years ago
Years
ago
34 24 5.5 2 0104
Loxodonta cyclotis
(Africa)
Loxodonta
africana
(Africa)
Elephas
maximus
(Asia)
Mammuthus
Stegodon
Platybelodon
Mammut
Deinotherium

Figure 1.7e-1
Millions of
years ago
Years
ago
34 24 5.5 2 0104
Stegodon
Platybelodon
Mammut
Deinotherium

Figure 1.7e-2
Millions of
years ago
Years
ago
34 24 5.5 2 0104
Loxodonta cyclotis
(Africa)
Loxodonta
africana
(Africa)
Elephas
maximus
(Asia)
Mammuthus

THE PROCESS OF SCIENCE

1.8 In studying nature, scientists
make observations and form and
test hypotheses
• Science is a way of knowing that stems from
our curiosity about ourselves and the world
around us.
• Science is based upon inquiry, the search for
information and explanations of natural
phenomena.
• Scientists typically
– make observations,
– form hypotheses, proposed explanations for a set
of observations, and© 2016 Pearson Education, Ltd.

test hypotheses
• Two types of data are frequently collected in
scientific investigations.
1. Qualitative data is descriptive.
2. Quantitative data includes numerical
measurements.

test hypotheses
• Scientists use two types of reasoning.
1. Inductive reasoning makes generalizations based
on collecting and analyzing a large number of
specific observations.
2. Deductive reasoning flows from general
premises to predicted and specific results.

test hypotheses
• We solve everyday problems by using
hypotheses.
– A common example would be the reasoning we
use to answer the question, “Why doesn’t a
flashlight work?”
– Two reasonable hypotheses are that
1. the batteries are dead or
2. the bulb is burned out.

Figure 1.8-1
Observation:
Flashlight doesn’t work.
Question:
Why doesn’t the
flashlight work?
Hypothesis #1:
Batteries are dead.
Hypothesis #2:
Bulb is burned out.

Figure 1.8-2
Observation:
Question:
Why doesn’t the
flashlight work?
Hypothesis #1:
Batteries are dead.
Hypothesis #2:
Bulb is burned out.
Prediction:
Replacing batteries
will fix problem.
Prediction:
Replacing bulb
will fix problem.
Test of prediction:
Replace batteries.
Test of prediction:
Replace bulb.

Figure 1.8-3
Observation:
Question:
Why doesn’t the
flashlight work?
Hypothesis #1:
Batteries are dead.
Hypothesis #2:
Bulb is burned out.
Prediction:
Replacing batteries
will fix problem.
Prediction:
Replacing bulb
will fix problem.
Test of prediction:
Replace batteries.
Test of prediction:
Replace bulb.
Results:
Hypothesis is contradicted.
Results:
Flashlight works.
Hypothesis is supported.

test hypotheses
• A scientific theory is
– much broader in scope than a hypothesis and
– supported by a large and usually growing body of
evidence.
• Science is a social activity in which scientists
– work in teams,
– share information through peer-reviewed
publications, meetings, and personal
communication, and
– build on and confirm each other’s work.© 2016 Pearson Education, Ltd.

1.9 SCIENTIFIC THINKING:
Hypotheses can be tested using
controlled field studies
• Scientists conducted a controlled experiment
to test the hypothesis that color patterns have
evolved as adaptations that protect animals
from predation.
• The experiment compared an experimental
group consisting of noncamouflaged mice
models and a control group consisting of
camouflaged models that matched the mice
native to each area.
• The groups differed by only one factor, the© 2016 Pearson Education, Ltd.

Figure 1.9-0
Beach population Inland population

Figure 1.9-1
Beach population

Figure 1.9-2
Inland population

1.9 SCIENTIFIC THINKING:
Hypotheses can be tested using
controlled field studies
• As presented in Table 1.9,
– the noncamouflaged models had a much higher
percentage of attacks in the beach and inland
habitats and
– these data fit the key prediction of the camouflage
hypothesis.

Table 1.9

BIOLOGY AND EVERYDAY LIFE

1.10 EVOLUTION CONNECTION:
Evolution is connected to our
everyday lives
• Evolution is a core theme of biology.
• Humans selectively breed plants and animals
in the process of artificial selection to
produce
– move productive crops,
– better livestock, and
– a great variety of pets that bear little resemblance
to their wild ancestors.

1.10 EVOLUTION CONNECTION:
Evolution is connected to our
everyday lives
• Humans also unintentionally cause
– the evolution of antibiotic-resistant bacteria,
– the evolution of pesticide-resistant pests, and
– the loss of species through habitat loss and global
climate change.

Figure 1.10

1.11 CONNECTION: Biology,
technology, and society are
connected in important ways
• Many issues facing society
– are related to biology and
– often involve our expanding technology.
• The basic goals of science and technology
differ.
– The goal of science is to understand natural
phenomena.
– The goal of technology is to apply scientific
knowledge for some specific purpose.

1.11 CONNECTION: Biology,
technology, and society are
connected in important ways
• Although their goals differ, science and
technology are interdependent.
– Research benefits from new technologies.
– Technological advances stem from scientific
research.
• Technologies of DNA manipulation are the
results of scientific discovery of the structure
of DNA.

You should now be able to
1. Describe seven properties common to all life.
2. Describe the levels of biological organization from
molecules to the biosphere, noting the
interrelationships between levels.
3. Define the concept of emergent properties and describe
an example of it.
4. Explain why cells are a special level in biological
organization. Compare prokaryotic and eukaryotic cells.
5. Compare the dynamics of nutrients and energy in an
ecosystem.

6. Explain how DNA encodes a cell’s information.
7. Compare the three domains of life.
8. Describe the process and products of natural selection.
9. Distinguish between quantitative and qualitative data.
10. Compare the definitions and use of inductive and
deductive reasoning in scientific investigations.
11. Distinguish between a scientific theory and a
hypothesis.

12. Describe the structure of a controlled experiment and
give an example.
13. Explain how evolution impacts the lives of all humans.
14. Compare the goals of science and technology. Explain
why an understanding of science is essential to our
lives.

Figure 1.UN01
ENERGY FLOW
Light
Producers
Chemical
energy
Consumer
Heat

Figure 1.UN02

Figure 1.UN03
Observations Inferences
Heritable
variations
Overproduction
of offspring
Natural selection:
Unequal reproductive
success leads to
evolution of adaptations
in populations.

Figure 1.UN04
Biology
is the study of
(a)
(b)
(c)
(d)
(e)
DNA
(genetic code)
diversity of life
cells as basic
units of life
common properties
of living organisms
has changed
through the process of
mechanism is
depends on
accounts
for accounts
for
leads to codes for
is evidence of
seen in
seen in
variations in seen in

Figure 1.UN05
No reward
Food reward
Day
Averagetimeto
completemaze(min)
25
20
15
10
5
0
0 1 2 3 4 5 6

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