1. Darwin’s Theory of Evolution The Puzzle of Life’s Diversity Chapter 15-1
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2. The total variety of all the organisms in the biosphere
= ________________
Where did all these different organisms come from?
How are they related?
BIODIVERSITY

3. What scientific explanation can account for the diversity of life?
ANSWER:
A collection of ______________,
__________, and ___________ known as
________________________
Scientific facts
observations
hypotheses
EVOLUTIONARY THEORY

4. 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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5. Who Was Charles Darwin? Galápagos Islands finches tortoises
While on his voyage around the world aboard the ____________, Charles Darwin spent about one month observing life on the
________________.
There, he encountered some unique animals, such as ______ and ________.
H.M.S. Beagle
Galápagos Islands
finches
tortoises

6. 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

7. 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…

8. 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

9. Darwin’s Theory of Evolution Ideas that Shaped Darwin’s Thinking Chapter 15-2
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10. Ideas that shaped Darwin’s thinking: In 1785 ______________
proposes that the
______________ by
_________________
occurring over
__________ periods of
time, and is
_______________ old.
James Hutton
Earth was shaped
geological forces
very long
millions of years

11. 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

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

13. 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

14. 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

15. The male fiddler crab uses its
front claw to attract mates and
ward off predators.
Through repeated use, the front
claw becomes larger.
The fiddler passes on this acquired characteristic to its offspring

16. 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.

17. 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