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Science Log pg. 32 Peppered Moths

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1 Science Log pg. 32 Peppered Moths
Of the four parts of Natural Selection, which was best represented in the evolution of the peppered moths? Explain

2 EVOLUTION: Descent with modification

3 Age of the Earth Scientists estimate Earth to be 4.6 billion years old
Does not look today as it once did, nor do the organisms on it

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5 Change over time Earth is very old! Has changed a great deal.
Different atmosphere Different temp. Collisions from outer space Some organisms have stayed about the same as they were millions of years ago (sharks). Some have changed. Some have disappeared.

6 Adaptation Traits that an organism uses to survive and reproduce in it’s environment. They are passed on from parent to offspring. Example: How are Polar bears adapted to life in the Arctic? Why would they not be well adapted to life in Hawaii? Can include structures or behaviors Sea Turtles bury their eggs in the sand. How is this behavior an adaptation?

7 Species Living things that share the same characteristics and adaptations Can mate with one another to produce offspring that are fertile (can reproduce) Species have changed over time

8 Species change too… Many different life forms have existed through Earth’s history Evidence for this comes from fossils Why do species change? Due to evolution Small changes in a species because of natural selection add up over millions of years! Mutations in an organism’s DNA, although most often bad, can sometimes result in an adaptation. If this mutation helps the organism survive it will passed on to its offspring.

9 Evidence! Key evidence to support evolution comes from fossils
Generally found in sedimentary rock (particles of sand, dust and soil form layers, with oldest at the bottom) Fossils tell us that some species have died out, while some have changed greatly Why??

10 Because of EVOLUTION “Descent with Modification”
Organisms change over time, to what suits their survival the best Example: Giraffe

11 Must Have: Overproduction (too many babies) Variation (different traits C "Struggle for Existence" “Success = Reproduction and passing on the trait”

12 C Giraffes with longer necks get better food, have more babies (have an advantage in the struggle for existence) C Longer necks make more long necks (so that trait gets inherited)

13 Results: Over time, average neck length increases

14 **Extinctions may occur, which allow others to take over
Other conditions: **New species can form **Extinctions may occur, which allow others to take over *Extinction happens when adaptations fail to keep up with changes to the environment. Okapi (relative of the giraffe)

15 How do New Species Form? Speciation

16 Steps to a New Species Separation Adaptation
Selection (reproductive isolation)

17 More evidence for evolution
1. Comparing Skeletons: Different organisms have same basic structure = common ancestor

18 2. Fossil Evidence At first glance, whales may seem similar to fish. But whales have all the characteristics of a mammal. Scientists believe that the ancient ancestor of whales was a land mammal. A more recent ancestor was a mammal that spent some time in water and some time on land. There is fossil evidence to support this hypothesis.

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21 Things that have been left over as evolution takes place.
3. Vestigial Structures Physical structures or behavior that is no longer necessary for an organism to survive or reproduce in it’s environment. Things that have been left over as evolution takes place. Scientists think that the appendix may be a vestigial structure. Vestigial Structure Vestigial Structure

22 4. Comparing DNA from different species
All organisms have the same type of DNA Organisms that are more closely related have more similar sequences of DNA (example: humans and chimpanzees, only million base pair differences

23 5. Embryonic Structures Early in development all embryos look amazingly similar Common ancestor?

24 Were you paying attention?
1. What is evolution? 2. Organisms are considered members of the same species if…. A. B.

25 Were you paying Attention Cont.
3. What are the 3 steps to speciation (the forming of a new species) 4. What are 5 examples of evidence in support of the Theory of Evolution?

26 Branching Tree Diagrams
Scientists use branching tree diagrams to show how they think organisms are related. They are kind of like family trees. They use fossil evidence, comparative anatomy (comparing skeletons), and DNA comparisons

27 Which animal is most closely related to whales?

28 Which groups of animals are still alive today?
How can you tell? Why do the lines get wider or thinner? What does the branching tree diagram tell us about snakes and lizards?

29 Read “Evidence of Whale Evolution” pg. 302-303
On pg. 11 in your ISN, describe the evidence (at least 4 pieces of evidence). How does this evidence support the idea that modern day whales have an ancestor that used to walk on land (one + complete sentence)? When you finish, please get your computer (edmodo)

30 Science Log: Evidence of Evolution pg. 16 in ISN
Using your textbook (Chapter 10 – Section 1) and your power point notes, record four or more types of evidence that scientists use to support the Theory of Evolution. Name and briefly describe each type of evidence in one complete sentence (minimum of 4 sentences) HW: Marshmallow Lab on pg. 17; Peppered Moths pgs ; Words to Watch pg. 15


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