1. Natural Selection and the Evidence of Evolution
Section 15.1
Offset your 3 papers and make a foldable.
Title the top flap the title above
Title the Other flaps:
What is evolution?
Darwin-Travels and Influence
Natural Selection
Evidences—Adaptations, Fossil
Evidences—Anatomical, Embyological, Biochemical

2. Flap 1--What is evolution?
The change in populations over time.

3. Flap 2--Who is Charles Darwin?
English scientist/naturalist whose ideas provide foundation for the theory of evolution by natural selection
Sailed on HMS Beagle for 5 years studying and collecting biological and fossil specimens

5. Major Ports of Call… Galapagos Islands
Location: Near equator, 1000km off west coast of S. America
What he studied: many species of animals and plants unique to the island, but are similar elsewhere
Major findings: Observations led to his consideration that species change over time

6. Thomas Malthus’ Influence on Darwin
Proposed idea that human populations grow faster than Earth’s food supply

7. Darwin’s book…
1859, The Origin of Species
Detailed account on his ideas and theories that support evolution

8. Flap 3—Natural Selection
Realized organisms struggle to compete in changing environments. Many types of competition exist:
Food and space
Escaping predators
Location of shelter

9. Insights into why only certain individuals survive…
Traits vary among populations; these traits are inherited
Breeding with others that had desirable traits produced offspring with these traits

10. Darwin’s Hypothesis…
Artificial Selection- breeding organism with specific traits in order to produce offspring with identical traits
There is force in nature that works like artificial selection

11. What is natural selection?
Mechanism of change in populations over time

12. Flap 4-What are adaptations?
Variation that aids an organisms chances of survival in its environment
Develop in a species over many generations

13. Structural Adaptations Examples
Teeth and Claws
Protect against predators
Mimicry
Enables one species to resemble another
Camouflage
Enables species to blend with surroundings

14. Physiological Adaptation
What are they?
Changes in organism’s metabolic processes
Example:
After years of exposure to specific pesticides, insects and weeds have become resistant

15. Fossil Evidence Indirect source
Provide record of early life based upon rock layers and location of fossils within them.
As record becomes more complete, the sequence of evolution is clearer

16. earliest, most primitive bird ~145 mya
Example: Archeoptryx
earliest, most primitive bird ~145 mya

17. Flap 5-Anatomical Evidence
Homologous- common evolutionary origin, features have similar structure
but have different functions. Ex-bat wing and human hand

18. Anatomical Evidence
Analogous- no common ancestor, but similar in function. Organisms like the shark and dolphin evolved sleek bodies because they live in similar environments, not because they are related.

19. Anatomical Evidence
Vestigial- body structure in present day organism that no longer serves original purpose

20. Embryological Evidence
The more similar the embryos through out development the closer the evolutionary relationship.

21. Biochemical Evidence Great table on page 403!
All organisms share DNA, ATP and many enzymes among their biochemical molecules . The more changes the more time that has passed since they shared a common ancestor.