1. KEY CONCEPT There were theories of biological and geologic change before Darwin.

2. Early scientists proposed ideas about evolution.
Evolution is the biological change process by which descendants come to differ from their ancestors.
A species is a group of organisms that can reproduce and have fertile offspring.

3. Theories of geologic change set the stage for Darwin’s theory.
There were three theories of geologic change.
catastrophism
gradualism
uniformitarianism

4. Uniformitarianism is the prevailing theory of geologic change.

5. KEY CONCEPT Darwin’s voyage provided insight on evolution.

6. Darwin observed differences among island species.
Variation is a difference in a physical trait.
Galápagos tortoises that live in areas with tall plants have long necks and legs.
Galápagos finches that live in areas with hard-shelled nuts have strong beaks.

7. What he saw:
Tortoises on Galapagos had:
Birds on Galapagos had:
Examples in the current world:

8. MOVIE- ROCK POCKET MICE

9. An adaptation is a feature that allow an organism to better survive in its environment.
Species are able to adapt to their environment.
Adaptations can lead to genetic change in a population.
What are some human adaptations?

10. Darwin observed fossil and geologic evidence supporting an ancient Earth.
Darwin found fossils of extinct animals that resemble modern animals.

11. He saw land move from underwater to above sea level due to an earthquake.
Darwin extended his observations to the evolution of organisms.

12. KEY CONCEPT Darwin proposed natural selection as a mechanism for evolution.

13. Several key insights led to Darwin’s idea for natural selection.
Darwin noticed a lot of variation in domesticated plants and animals.
Artificial selection is the process by which humans select traits through breeding.
neck feathers
crop
tail feathers

14. How can we see that in our world today?
Artificial selection is controlled breeding by humans to produce more individuals with specific traits.
How can we see that in our world today?
Dog breeding
How do companies benefit from artificial selection?
Food supply
Medicine

15. Natural selection is a mechanism by which individuals that have inherited beneficial adaptations produce more offspring on average than do other individuals.
Heritability is the ability of a trait to be passed down.
There is a struggle for survival due to overpopulation and limited resources.
Darwin proposed that adaptations arose over many generations.

16. Natural selection explains how evolution can occur.
There are four main principles to the theory of natural selection.
Variation-
overproduction-
adaptation-
descent with modification-
Fitness is the measure of survival ability and ability to produce more offspring.

17. Natural selection acts on existing variation.
Natural selection can act only on traits that already exist.
Structures take on new functions in addition to their original function.
wrist bone
five digits

18. Why are adaptations important?
Adaptations: are characteristics that an organisms HAS not grows: If the environment changes, which animals survive?
Fitness is the measure of an animals ability to reproduce and survive.
You must be born with a trait to pass it to your offspring.
Some traits you acquire throughout your life. Those are not adaptations that will be passed down.
Adaptations are traits that you have the are good for an environment.
If a wolf has a really thick coat and the weather becomes really cold- he survives, he reproduces, and his offspring would live to pass on the thick coat.
What happens if you don’t have a specific characteristic?
The animal doesn’t reproduce or doesn’t survive

19. KEY CONCEPT Evidence of common ancestry among species comes from many sources.

20. Evidence for evolution in Darwin’s time came from several sources.
Fossils provide evidence of evolution.
Fossils in older layers are more primitive than those in the upper layers.

21. Fossils Which is younger? Older?
Fossils: fossils can be looked at over time.
(Sect 12.1) Law of superposition: rock layer at the top is younger than rock layer at the bottom.
(Sect 12.1) Fossils can be dated. Radiometric dating helps to use molecules to decide how old a fossil is. Half-life**
Fossils can be compared between different layers of rock to decide there relative age

22. The study of geography provides evidence of evolution.
Geographical locations have different characteristics, but sometimes very similar animals (biogeography)

23. Embryology provides evidence of evolution.
identical larvae, different adult body forms
similar embryos, diverse organisms
Larva
Adult barnacle
Adult crab

24. Embryology Who are you looking at?
Embryology: Embryos of many organisms are VERY similar. If they are not related, why are they so similar? What do the embryos share?

25. The study of anatomy provides evidence of evolution.
Homologous structures are similar in structure but different in function.
Homologous structures are evidence of a common ancestor.
Human hand
Bat wing
Mole foot

26. The study of anatomy provides evidence of evolution.
Analogous structures have a similar function, but different structure.
Human hand
Bat wing
Mole foot
Fly wing
Analogous structures are not evidence of a common ancestor.

27. Anatomy physical structures of organisms can support evolution
Homologous structures: bat wing, whale fin, and human arm
Show common ancestry
Similar in structure, but different function
Analogous structures: bird wing & butterfly wing
NOT common in ancestry
Similar in function, but different structure

28. Structural patterns are clues to the history of a species.
Vestigial structures are remnants of organs or structures that had a function in an early ancestor.
Ostrich wings are examples of vestigial structures.

29. KEY CONCEPT New technology is furthering our understanding of evolution.

30. Fossils provide a record of evolution.
Paleontology is the study of fossils or extinct organisms.

31. Paleontology provides evidence to support evolution.

32. Molecular and genetic evidence support fossil and anatomical evidence.
Two closely-related organisms will have similar DNA sequences.

33. Pseudogenes are sequences providing evidence of evolution.
no longer function
carried along with functional DNA
can be clues to a common ancestor

34. Evolution unites all fields of biology.
Scientist from any fields contribute to the understanding of evolution.
The basic principles of evolution are used in many scientific fields.