The document outlines key learning goals about evolution and natural selection, as introduced by Charles Darwin, including definitions, processes, and evidence supporting the theory. It explains the four steps of natural selection: overproduction, variation, competition, and selection, and emphasizes the role of variation in adapting to changes. Additionally, it describes Darwin's observations during his voyage on the HMS Beagle, particularly in the Galapagos Islands, and how these led to his hypotheses regarding species divergence.

1. Evolution

2. Learning Goals
 1. Define "Evolution" & "Natural Selection".
 2. Describe the 4 steps of Natural Selection,
giving an example of each.
 3. Explain the importance of "Variation".
 4. Does Natural Selection act on an
organism phenotype or genotoype? Explain!
 5. List the 5 evidences that support the
Theory of Evolution.

3. Theory of Evolution
Theory of Evolution
 Evolution
The process of change over time.
 Specifically, a change in the frequency
of a gene or allele in a population over
time

4. Charles Darwin
Charles Darwin
 Father of Evolution
 Proposed a mechanism for
evolution, natural selection
natural selection
 Darwin went on a 5-year trip
around the world on the ship,
the HMS Beagle
 As the ship’s naturalist, he made
observations of organisms in
South America and the Galapagos
Islands
•Wrote a book,
Wrote a book, “
“Origin of the Species
Origin of the Species”
”

5. Voyage of the Beagle

6. Voyage of Beagle
 Dates: February 12th, 1831
 Captain: Charles Darwin
 Ship: H.M.S. Beagle
 Destination: Voyage around the world.
 Findings: evidence to propose a
revolutionary hypothesis about how life
changes over time

8. Video on Darwin
https://youtu.be/6GNUlZhE_jE -Darwin
https://youtu.be/ZbITQ0dqxCQ
Galapagos Island
https://youtu.be/XOiUZ3ycZwU
Theory

10. Patterns of Diversity
Darwin visited Argentina and Australia which
had similar grassland ecosystems.
those grasslands were inhabited by very different
animals.
neither Argentina nor Australia was home to the
sorts of animals that lived in European
grasslands.

11. Patterns of Diversity
 Darwin posed challenging questions.

Why were there no rabbits in Australia, despite
the presence of habitats that seemed perfect for
them?

Why were there no kangaroos in England?

12. Patterns of Diversity
Darwin collected the preserved remains
of ancient organisms, called fossils.
Some of those fossils resembled
organisms that were still alive today.

13. The Galapagos Island

14. The Galapagos Island
 Darwin was fascinated in particular by the
land tortoises and marine iguanas in the
Galápagos.
 Giant tortoises varied in predictable ways
from one island to another.
 The shape of a tortoise's shell could be used
to identify which island a particular tortoise
inhabited.

15. Animals found in the Galapagos
Land Tortoises
Darwin Finches
Marine Iguanas

16. Darwin’s Finches

17. The Journey Home
Darwin Observed that characteristics of
many plants and animals vary greatly
among the islands.
Hypothesis: Separate species may
have arose from an original ancestor

19. Natural Selection
Natural Selection
 Natural Selection:
Organisms that are best adapted to an
environment survive and reproduce more
than others

20.  Darwin’s Theory of Natural Selection
occurs in four steps:
 Overproduction
 Variation
 Competition
 Selection

21. 1. Overproduction
1. Overproduction
 Each species produces more
offspring that can survive

22. 2. Variation
2. Variation
 Each individual has a
unique combination of
inherited traits.
 Adaptation:
Adaptation: an inherited
trait that increases an
organism’s chances of
survival

23. Why is Variation Important?
 Because the environment changes.
 The more variation
variation within
within a species
a species, the more
likely it will survive
survive
 EX: If everyone is the same, they are all vulnerable
to the same environmental changes or diseases
 The more variation of
variation of types of
types of species
species in an
habitat, the more likely at least some will
some will
survive
survive
 EX: Dinosaurs replaced by mammals

24. Which community has a better
Which community has a better
chance of surviving a natural
chance of surviving a natural
disaster?
disaster?
Community A
Community A Community B
Community B

25. 3
3. Competition
. Competition
 Individuals COMPETE for limited
resources:
 Food, water, space, mates
 Natural selection occurs through
“Survival of the fittest
Survival of the fittest”
 Fitness
Fitness: the ability to survive and reproduce
 Not all individuals survive to adulthood

26. 4. Selection
4. Selection
 The individuals with the best traits /
best traits /
adaptations will survive and have the
adaptations will survive and have the
opportunity to pass on it
opportunity to pass on it’
’s traits
s traits to offspring.
 Natural selection acts on the phenotype
(physical appearance), not the genotype (genetic
makeup)
 Ex: When a predator finds its prey, it is due to
the prey’s physical characteristics, like color or
slow speed, not the alleles (BB, Bb)

27.  Individuals with traits that are not well
suited to their environment either die or
leave few offspring.
 Evolution occurs when good traits build
good traits build
up in a population
up in a population over many
generations and bad traits are eliminated
bad traits are eliminated
by the death of the individuals
by the death of the individuals.

28. Peppered Moth
 Which moth will the bird catch?
A
B

35. What is Artificial Selection?