Adaptation:Adaptation:Darwin’s VoyageDarwin’s Voyage

Chapter Seven Holt TextChapter Seven Holt Text

7.27.2

Charles DarwinCharles Darwin

1. Who was Charles 1. Who was Charles Darwin?Darwin?

1.1. British NaturalistBritish Naturalist

In 1831, set out on a 5-In 1831, set out on a 5-year trip around the year trip around the world.world.

Job: to learn as much Job: to learn as much as possible about as possible about the living things he the living things he saw.saw.

HMS BeagleHMS BeagleLife Science: Evolution (click here)Life Science: Evolution (click here)

Darwin’s Excellent Darwin’s Excellent AdventureAdventure

2. What did Darwin 2. What did Darwin observe?observe?

2. Great diversity of 2. Great diversity of living things.living things.

Collected 1,000’s of Collected 1,000’s of plant and animal plant and animal samplessamples

Took MANY notesTook MANY notes

2. What did Darwin 2. What did Darwin observe?observe?

2. First stops were in 2. First stops were in Brazil, Argentina and Brazil, Argentina and later Galapagos later Galapagos Islands.Islands.

2. What did Darwin 2. What did Darwin observe?observe?

2. Noticed that some 2. Noticed that some species were present species were present in several locations; in several locations; however they had however they had some different traits.some different traits.

Click pic

3. What is a 3. What is a speciesspecies?? 3. A group of similar 3. A group of similar organisms that can organisms that can mate and produce mate and produce fertile offspring.fertile offspring.

1.7 million species 1.7 million species identified so faridentified so far

Darwin’s FinchesDarwin’s Finches

4. How were the 4. How were the animals different?animals different?

4. Finches4. Finches

Darwin noticed that the Darwin noticed that the finches on the finches on the Galapagos Islands Galapagos Islands were similar to the were similar to the ones found in ones found in Equador but slightly Equador but slightly different.different.

He noticed that the beaks of the finches He noticed that the beaks of the finches had adapted to the way each finch had adapted to the way each finch usually gets food.usually gets food.

Galapagos FinchesGalapagos Finches

4. How were the 4. How were the animals different?animals different?

4. Iguanas-4. Iguanas-

On S. America: green On S. America: green with small claws (live with small claws (live in rain forest)in rain forest)

On G. Islands: gray On G. Islands: gray with larger claws (live with larger claws (live on beach)on beach)

4. How were the 4. How were the animals different?animals different?

4. On G. Islands4. On G. Islands

Tortoises had different Tortoises had different shell shapes and shell shapes and patterns on different patterns on different islands.islands.

Darwin’s ThinkingDarwin’s Thinking

5. What was Darwin’s 5. What was Darwin’s hypothesis?hypothesis?

5. Island animals were 5. Island animals were separated from separated from mainland relatives. mainland relatives. Each population Each population adapted to its adapted to its environment.environment.

6. What is an 6. What is an adaptationadaptation??

6. A trait that helps an 6. A trait that helps an organism survive and organism survive and reproduce. reproduce.

7. Example of 7. Example of adaptation?adaptation?

7. For finches that ate 7. For finches that ate insects, those with insects, those with sharpest beaks were sharpest beaks were able to catch more able to catch more bugs. bugs.

These survived longer These survived longer and were more likely and were more likely to reproduce.to reproduce.

Their offspring likely to Their offspring likely to have sharp beaks…have sharp beaks…

7. Example of 7. Example of adaptation?adaptation?

7. Iguanas7. Iguanas

(Compare those who (Compare those who lived in the jungle to lived in the jungle to those on the island those on the island beach.)beach.)

8. What is 8. What is evolutionevolution?? 8. Gradual change in a 8. Gradual change in a species over time. species over time.

Happens over many Happens over many years.years.

Darwin’s Theory of Darwin’s Theory of Natural SelectionNatural Selection

9. What was Darwin’s 9. What was Darwin’s book calledbook called

9. 9. The Origin of The Origin of SpeciesSpecies

It summarized his ideas It summarized his ideas about how organisms about how organisms adaptadapt

Darwin’s Theory of Darwin’s Theory of Natural SelectionNatural Selection

9. What is 9. What is natural natural selectionselection??

9. Process by which 9. Process by which individuals that are individuals that are better adapted to better adapted to their environment are their environment are more likely to survive more likely to survive and reproduce. and reproduce.

9. What is 9. What is natural natural selectionselection??

9. 9. NatureNature selects for selects for certain traits in an certain traits in an organism because of organism because of conditions in the conditions in the environment.environment.

10. Natural selection is 10. Natural selection is like _________.like _________.

10. Selective breeding10. Selective breeding

It works to produce It works to produce organisms with the organisms with the best traits.best traits.

11. Four factors that 11. Four factors that affect natural affect natural selection:selection:

11. 11.

OCVSOCVS

11. Three factors that 11. Three factors that affect natural affect natural selection:selection:

11. 11. Overproduction:Overproduction:

Most species produce Most species produce many more offspring many more offspring than can survive.than can survive.

Increases chances that Increases chances that at least one will at least one will survive.survive.

11. Three factors that 11. Three factors that affect natural affect natural selection:selection:

11. 11. Competition:Competition:Food and other Food and other

resources limited. resources limited. Offspring must Offspring must compete to get food, compete to get food, escape predators.escape predators.

The strongest ones will The strongest ones will survive.survive.

11. Three factors that 11. Three factors that affect natural affect natural selection:selection:

11. 11. Variation:Variation:

Different alleles of Different alleles of genes give different genes give different traits.traits.

Some traits help Some traits help organism survive. Ex: organism survive. Ex: faster swimmersfaster swimmers

11. Three factors that 11. Three factors that affect natural affect natural selection:selection:

11. 11. Successful Successful Reproduction:Reproduction:

The best adapted The best adapted organisms are likely organisms are likely to have many to have many offspring that survive.offspring that survive.

12. Role of genes in 12. Role of genes in adaptationadaptation

12. Genes carry 12. Genes carry instructions for traits instructions for traits and are passed from and are passed from parent to offspring.parent to offspring.

13. How do new 13. How do new species form?species form?

13. A group of 13. A group of individuals gets individuals gets separated from the separated from the rest long enough for rest long enough for traits to evolve.traits to evolve.

(By a river, ocean, (By a river, ocean, earthquake, earthquake, mountains)mountains)

14. Examples of 14. Examples of adaptationadaptation

14. Monarch butterfly 14. Monarch butterfly and viceroy moth.and viceroy moth.

Viceroy Moth Monarch Butterfly

14. Examples of 14. Examples of adaptationadaptation

14. Peppered Moth14. Peppered Moth

Peppered MothPeppered MothLight Variety

Dark Variety

The usual form of the peppered moth Biston betularia in northern The usual form of the peppered moth Biston betularia in northern Europe has a light 'peppered' pattern of coloration. The moth rests Europe has a light 'peppered' pattern of coloration. The moth rests on tree branches and its color pattern camouflages it against on tree branches and its color pattern camouflages it against predatory attack. The camouflage only works against the right predatory attack. The camouflage only works against the right background: birds are more likely to eat poorly camouflaged background: birds are more likely to eat poorly camouflaged moths, which therefore have a lower fitness. moths, which therefore have a lower fitness.

The light coloration of tree branches is mainly caused by lichens The light coloration of tree branches is mainly caused by lichens that grow there. Smoke pollution in the industrial revolution in the that grow there. Smoke pollution in the industrial revolution in the UK killed these lichens near to industrial areas, leaving tree UK killed these lichens near to industrial areas, leaving tree branches black. At about this time, around 1830, a 'melanic' form branches black. At about this time, around 1830, a 'melanic' form of the peppered moth becomes increasingly common in of the peppered moth becomes increasingly common in contemporary moth collections. The melanic form is camouflaged contemporary moth collections. The melanic form is camouflaged on dark tree branches. Through the 19th century, the melanic on dark tree branches. Through the 19th century, the melanic form increased in frequency until, near industrial regions, it was form increased in frequency until, near industrial regions, it was the normal type of the moth. The increase was almost certainly the normal type of the moth. The increase was almost certainly driven by natural selection. driven by natural selection.