1. The Father of Evolution
Charles Darwin
The Father of Evolution

2. Charles Darwin Born in 1809, Shrewsbury, England Naturalist
Studied Medicine
Degree in Theology
Buried in Westminster Abbey

3. Darwin’s Theory of Evolution
Evolution, or change over time, is the process by which modern organisms have descended from ancient organisms.
A scientific theory is a well-supported testable explanation of phenomena that have occurred in the natural world.

4. Ideas that shaped Darwin’s Thinking
James Hutton:
1795 Theory of Geological change
Forces change earth’s surface shape
Changes are slow
Earth much older than thousands of years

5. Ideas that Shaped Darwin’s Thinking
Charles Lyell
Book: Principles of Geography
Geographical features can be built up or torn down
Darwin thought if earth changed over time, what about life?

6. Lamarck’s Theory of Evolution
Tendency toward Perfection(Giraffe necks)
Use and Disuse (bird’s using forearms)
Inheritance of Acquired Traits

9. Population Growth Thomas Malthus-19th century English economist
If population grew (more Babies born than die)
Insufficient living space
Food runs out
Darwin applied this theory to animals

10. Another influential scientist
Alfred Russel Wallace
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Another influential scientist
Botanist
Contribution:
Essay described evolution by natural selection
Alfred Russel Wallace
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11. Publication of Orgin of Species
Russel Wallace wrote an essay summarizing evolutionary change from his field work in Malaysia
Gave Darwin the drive to publish his findings

12. 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

13. Row, row, row your boat! Voyage of H.M.S. Beagle 5 year unpaid voyage
Darwin studied plants, animals, collected fossils
Found fossils of extinct animals that were similar to modern species. On the Galapagos Islands in the Pacific Ocean he noticed many variations among plants and animals of the same general type as those in South America.

14. This voyage lasted from 1831 to 1836.

15. Many of Darwin’s conclusions were based on observations of wildlife in the Galapagos Islands.
The Galapagos Islands lie 500 miles west of Ecuador in the Pacific Ocean, directly on the equator.
“Galapagos” means turtle.

16. The Galapagos Island
The smallest, lowest islands were hot, dry, and nearly barren-Hood Island-sparse vegetation
The higher islands had greater rainfall and a different assortment of plants and animals-Isabela- Island had rich vegetation.

17. Animals found in the Galapagos
Land Tortoises
Darwin Finches
Blue-Footed Booby
Marine Iguanas

18. Darwin noticed there were several types of finches on these islands.
Galapagos finches
Darwin noticed there were several types of finches on these islands.
In particular, Darwin observed something odd about the finches: they all looked like a bird he had seen on the South American continent.

19. In all, there were 13 types of finches, some species being confined to only one island.

20. The most distinct difference among finch species is their beaks, which are adapted for the specific diets available on the islands.

21. Darwin wondered if the birds and other animals had been created to match their environment, why didn’t these birds look like the birds of the African continent, since the environments of both the Galapagos and Africa were similar.

22. Once on the islands, the birds must have changed over the years.
Darwin guessed that some of the birds from South America migrated to the Galapagos.
Once on the islands, the birds must have changed over the years.

23. This would explain the numerous species of birds present.
large ground finch
woodpecker finch
cactus finch
This would explain the numerous species of birds present.

24. This tree has how many major branches?
Warbler Finch
Tree Finch
Ground Finch
Certhidea olivacea
& C. Fusca
Geospiza difficilis
G. conirostris
G. scandens
Cacts Finch
(nectar,eeds, blood)
G. magnirostris
Seed-eating Finch
G. fuliginosa
G. fortis
Platyspiza crassitrostris
C. heliobates
Cactospiza pallida
Woodpecker-like Finch
Vegetarian Finch
Insect-eating Finch
Camarhynchus pauper
C. psittacula
C. pauper
(seeds & insects)
PHYLOGENIC TREE:
A diagram showing the evolutionary history of a species of an animal.
This tree has how many major branches?

25. 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

26. Living Organisms and Fossils
Darwin collected the preserved remains of ancient organisms, called fossils.
Some of those fossils resembled organisms that were still alive today.

27. Living Organisms and Fossils
Others looked completely unlike any creature he had ever seen.
As Darwin studied fossils, new questions arose.
Why had so many of these species disappeared?
How were they related to living species?

28. Fossils

29. TWO TYPES OF EVOLUTION:
Convergent Evolution: process by which unrelated species become similar as they adapt to similar environments.
Divergent Evolution: formation of new species from an existing species adapting to new environments.
What type of evolution is a phylogenic tree?

30. After returning from the Galapagos and studying all the different types of plants & animals. Darwin concluded new concepts of change….

31. evolution Natural Selection Darwin called this…
which means (change in species over time)
Darwin extended these principles to biology, which helped him form his theory of…
Natural Selection
…or Survival of the Fittest.

32. Natural Selection & Artificial Selection
Natural variation--differences among individuals of a species
Artificial selection- nature provides the variation among different organisms, and humans select those variations they find useful.

33. Evolution by Natural Selection
The Struggle for Existence-members of each species have to compete for food, shelter, other life necessities
Survival of the Fittest-Some individuals better suited for the environment

34. Natural Selection
Over time, natural selection results in changes in inherited characteristics of a population. These changes increase a species fitness in its environment

35. Five basic components of
Natural Selection

36. 1. All species have genetic variation.
Every species is different, even within itself.
Look around you…are you all the same?

37. 2. The environment presents challenges to survival.
There is a constant struggle for survival. Examples are:
Drought
Fires
Floods
Snowstorms
Hurricanes
Tornadoes
Other natural disasters

38. 3. Organisms produce more offspring than can survive
3. Organisms produce more offspring than can survive. Competition exists WITHIN and AMONG species.
Within a Species
Among a Species
food
food
space
space
mates

39. Darwin’s definition of fitness:
4. Individuals that are fit to their environment leave more offspring than those who aren’t.
Darwin’s definition of fitness:
an organism which has successfully adapted to its environment
Organisms who possess favorable traits will leave more offspring.
In other words, he who spreads the most genes wins!
1st

40. 5. Characteristics of fit individuals increase in a population over time.
Over time, genes for less favored characteristics will be eliminated from the gene pool.
Example: giraffes and their long necks.

41. Therefore Darwin’s contributions:
Provided evidence that species evolve
In 1859, he proposed the Theory of Natural Selection to explain evolution (Survival of the fittest)
Over time, change within species leads to the replacement of old species by new species as less successful species become extinct.
Some evidence from fossils may prove that species on Earth have evolved from ancestral forms that are extinct. (species that have disappeared permanently.)

42. What is a species?
One or more populations of individuals that can interbreed, producing fertile offspring.
Speciation is the process by which new species are formed over time.

43. Equus, the modern horse, evolved from the dog-sized Hyracotherium
Equus, the modern horse, evolved from the dog-sized Hyracotherium. Notice it evolved from a four-toed front foot to the one-toed front foot of the modern horse.