1. Darwin’s Theory of Evolution The Puzzle of Life’s Diversity Chapter 15-1
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2. 15–1 The Puzzle of Life’s Diversity 1. Patterns of Diversity
Section Outline
Section 15-1
15–1 The Puzzle of Life’s Diversity
A. Voyage of the Beagle
B. Darwin’s Observations
1. Patterns of Diversity
2. Living Organisms and Fossils
3. The Galápagos Islands
C. The Journey Home

3. Definitions EVOLUTION:
THEORY:
FOSSIL:
change over time; the process by which modern organisms have descended from ancient organisms
a well-supported testable explanation of phenomena that have occurred in the natural world
the preserved remains of ancient organisms

4. evolution theory fossil ________ is a
The _______ that Darwin found caused him to ask questions that led to his proposal of the theory of
_________.
_______ provide evidence to support the theory of
fossils
________ is a
______; a testable explanation of naturally-occurring phenomena
Evolution
theory
evolution
Fossils
evolution
theory
fossil
The _____ record provides for some of the evidence that supports the ______ of evolution
fossil
theory

5. Charles Darwin H.M.S. Beagle 5 year The person who contributed the
The person who contributed the
most to our understanding of
evolution was
______________________
In 1831, at age 22, he joined the crew of
the _______________ as a naturalist for
a ________ voyage around the world.
Charles Darwin
H.M.S. Beagle
5 year
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6. Charles Darwin English naturalist
(1831) Set sail on the Beagle for a voyage around the world
During his travels, Darwin made many observations & collected a great deal of evidence, leading him to propose the theory of evolution

7. Cont. Charles Darwin
Collected fossils preserved remains of ancient organisms
Noticed that many plants & animals were very suited to their environments.
Spent much time in Galapagos Islands in Pacific Ocean near South America

8. DARWIN WONDERED? Why do Argentina and Australia have ________
______ even though they have _____________
_________?
Why are there no ______ in Australia and
no ________ in England?
Why have so many species
disappeared?
How are these ______ species
_______ to living species?
different
similar grassland
animals
ecosystems
rabbits
kangaroos
extinct
related

9. Some were hot and dry, with little vegetation.
The Galάpagos Islands are close together but have very different _______.
Some were hot and dry, with little vegetation.
Others had more rainfall and were rich in vegetation
Each island had
its own _____
_________ of
plant and animal
species.
climates
Biology by Miller and Levine; Prentice Hall Publishing©2006
unique
assortment

10. Giant Tortoises of the Galápagos Islands
Section 15-1
and on Pinta Island, tortoise necks
were somewhere in between
Pinta
Tower
Pinta Island Intermediate shell
Marchena
James
Fernandina
Santa Cruz
Isabela
Santa Fe
Hood Island
Saddle-backed shell
Floreana
Hood
On the desert-like Hood Island,
tortoises had long necks…
Isabela Island
Dome-shaped shell
…while on the lush rainforest of Isabela Island,
tortoises had short necks…

11. Tortoises from the Galapagos Islands

12. same species different isolated
After his voyage, Darwin spent a great deal of time thinking about his findings.
He began to wonder if animals living on
different islands had once been members
of the ____________ that had
developed _________ characteristics
after becoming _______ from one
another in different habitats.
Biology by Miller and Levine; Prentice Hall Publishing©2006
same species
different
isolated

13. Darwin’s Theory of Evolution Ideas that Shaped Darwin’s Thinking Chapter 15-2
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14. 1. Hutton and Geological Change 2. Lyell’s Principles of Geology
Section Outline
Section 15-2
15–2 Ideas That Shaped Darwin’s Thinking
A. An Ancient, Changing Earth
1. Hutton and Geological Change
2. Lyell’s Principles of Geology
B. Lamarck’s Evolution Hypotheses
1. Tendency Toward Perfection
2. Use and Disuse
3. Inheritance of Acquired Traits
4. Evaluating Lamarck’s Hypotheses
C. Population Growth

15. Ideas that shaped Darwin’s thinking: In 1785 ______________
proposes that the
______________ by
_________________
occurring over
__________ periods of
time, and is
_______________ old. Rocks can be pushed from the ocean floor to form __________.
James Hutton
Earth was shaped
geological forces
very long
millions of years
mountains

16. Ideas that shaped Darwin’s thinking: In 1833 ___________
explains that the geological
processes still ___________
have shaped Earth’s
features over
________________
Charles Lyell
occurring now
long periods of time

17. Ideas that shaped Darwin’s thinking:
Theory of Pangaea
…and continental
drift

18. insufficient space & food
Ideas that shaped Darwin’s thinking:
_____________________
He observed that babies were being born
faster than people were dying. He
reasoned that if the human population
continued to grow, sooner or later there
would be _______________________
Thomas Malthus (1798)
insufficient space & food

19. Jean-Baptiste Lamarck (1809)
Ideas that shaped Darwin’s thinking:
___________________________
was one of first scientists
to recognize living things
_______________ and that
all species were ________ from
other species.
Lamarck published his hypothesis of
________________________
the year Darwin was born.
Jean-Baptiste Lamarck (1809)
changed over time
descended
Inheritance of Acquired traits

20. The male fiddler crab uses its
front claw to attract mates and
ward off predators.
Through repeated use, the front
claw becomes larger.
Lamarck’s Hypothesis:
The fiddler passes on this acquired characteristic to its offspring
True or false?

21. What’s wrong with Lamarck’s hypothesis?
What’s wrong with Lamarck’s hypothesis?
Lamarck didn’t know about
genes and how traits are _______.
If you lifted weights your
whole young adult life, and
then you had children, would
your kids be more muscular?
inherited
NO! Acquired traits may help an organism, but they won’t be passed on to offspring.

22. What’s right with Lamarck’s hypothesis?
Lamarck was first to
develop a scientific
hypothesis about
_______
and recognize that
organisms are
________________________
evolution
adapted to their environments

23. Match the letter of the idea with the man or men who proposed it:
Hutton
Lyell
Malthus
Lamarck
Match the letter of the idea with
the man or men who proposed it:
The earth is really old, and slowly changes
Living things pass changes on to their offspring, leading to species changes
Sooner or later growing populations run out of resources
Living things change slowly over time because of competition for resources, and pass those changes on to their offspring

24. c.
Malthus
Hutton a.
Lamarck
Lyell b. d.
The earth is really old, and slowly changes
Living things pass changes on to their offspring, leading to species changes
Sooner or later growing populations run out of resources
Living things change slowly over time because of competition for resources, and pass those changes on to their offspring

25. Concept Map Section 15-3 Evidence of Evolution includes
The fossil record
Geographic distribution of living species
Homologous body structures
Similarities in early development
which is composed of
which indicates
which implies
which implies
Physical remains of organisms
Common ancestral species
Similar genes

26. Section 15.3 Darwin Presents His Case
The beaks of four species of Galapagos finches,
from Darwin's Journal of Researches, 1839.

27. Darwin’s Theory Darwin didn’t publish his ideas for 20 years!
Darwin published On the Origins of Species in 1859.
It provides evidence that evolution has occurred by NATURAL SELECTION.

28. Basis of Darwin’s Theory
His theory was based on artificial selection:
 Animal breeders breed animals only with desired traits. Those desired traits are passed down to the next generation.

29. Darwin’s Theory: Natural Selection
In nature, this is called NATURAL SELECTION.
 Individuals best suited to their environment survive & reproduce most successfully.
 AKA “Survival Of The Fittest” (sometimes called “Reproduction of the Fittest”)
 Struggle For Existence: is there an unlimited food supply?

30. Darwin’s Theory continued
Fitness ability to survive & reproduce in a specific environment
Results from adaptations, or inherited characteristics that increase the organism’s chances of survival.
Only the fittest organisms pass on their traits to offspring
Thus, the species changes over time.

31. How can you get an adaptation?
Can you “get” one at all?
Adaptations are inherited characteristics… you are born with them!
Adaptations are mutations that are beneficial in a particular environment!

32. Evidence of Evolution
A) Homologous structures structures that have different mature forms but develop from the same embryonic tissues
B) Similarities in early development, or embryology
C) Fossil record
D) Geographical distribution of living organisms (where the organisms are) 32

33. Homologous Structures33

34. Similarities in Embryology
In their early stages of development
Embryos of different species develop almost identically
This provides evidence that they share a common ancestry 34

35. 35