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Bellwork - Thurs T/F 1. Theories do not need evidence to support them.

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Presentation on theme: "Bellwork - Thurs T/F 1. Theories do not need evidence to support them."— Presentation transcript:

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2 Bellwork - Thurs T/F 1. Theories do not need evidence to support them.
2. Fossils provide evidence of organisms that lived in the past 3. The wing of a bat has bones that are similar to those in the human arm 4. DNA can tell us how closely related 2 organisms are. 5. Whales are descended from land dwelling mammals.

3 EQ: What evidence supports the theory of evolution?
Evidence of Evolution SC.7.L.15.1 EQ: What evidence supports the theory of evolution?

4 What evidence supports the theory of evolution?
Fossils Structural evidence Molecular biology (Similar DNA) Developmental Similarities (in embryos)

5 Did these organisms live at the same time?

6 What are fossils? The remains or imprints of once living organisms.

7 Where do fossils form Fossils can form in:
In Amber - small creatures are trapped in tree sap as it hardens In sedimentary rock – layers of rock In ice – may preserve some skin and hair

8 How do fossils show a change over time
Fossil record – all of the fossils that have been found It gives evidence about the order in which species have existed through time Upper layers = newer fossils Lower layers = older fossils

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10 2. How does Structural evidence support evolution?
Comparative Anatomy – the study of similarities and differences among structures of living things. Homologous Structures – body parts of bos Body structures or organisms with similar structure but may have a different function The more similar 2 structures are, the more likely they have a common ancestor.

11 Use the colors of the bat and cat bones to color similar bones in the human arm

12 Vestigial Structures – body parts that have lost their original function, but may have been useful in a common ancestor

13 Analogous Structures – Body parts have a similar function but different in structure. Shows that the 2 organisms are not closely related

14 How does Molecular biology support evolution?
Molecular biology – the study of gene structure and function The greater the number of similarities in 2 species DNA, the more recently the 2 species may have had a common ancestor.

15 Nitrogen base sequences
Whale - TCC TGGCA CTCCA GTGGT Hippo - CCC TGGCA GTGCA GTGCT

16 The table compares an amino acid (cytochrome c) found in the mitochondria of most organisms. It shows the differences between humans and other organisms. Which is least closely related to humans? Organism # of differences in cytochrome c Chimpanzee Rhesus monkey 1 Whale 10 Turtle 15 Bullfrog lamprey 20

17 The table compares an amino acid (cytochrome c) found in the mitochondria of most organisms. It shows the differences between humans and other organisms. Put the organisms in order from most closely related to least

18 How does Developmental evidence support evolution ?
Embryology – study of development of embryos from fertilization to birth If organisms develop in a similar way, they may share a common ancestor

19 1. Name 2 similarities in the structure of these embryos 2
1. Name 2 similarities in the structure of these embryos 2. which stage is the most difficult to tell them apart? 3. How do these similarities support evolution

20 Is a reptile more closely related to an amphibian or to a bird?

21 Exit: List the 4 types of evidence to support the theory of evolution.
How do the similar structures of the human arm and the bat wing bones support evolution? If you were looking at the DNA of 2 organisms and they had a common ancestor, what would you find? Which species in the table At right are most closely related To humans. Least?

22 Name the type of evidence:
The embryos of this hippo, frog, and rabbit all looked very similar in their early stages of development Snakes have traces of leg like structures that are not used for movement 3. Lucas finds a rock formation with footprints pressed into it. 4. The genetic material of 2 different species has some similarities. 5. A salamander embryo and a fish embryo have similar patterns of early development 6 Horses', donkeys', and zebras' bodies are set up in pretty much the same way

23 Bellwork Identify the type of evidence for evolution:
1. Snakes have traces of leg like structures that are not used for movement 2. Lucas finds a rock formation with footprints pressed into it. 3. The genetic material of 2 different species has some similarities. A salamander embryo and a fish embryo have similar patterns of early development Yesterday we talked about a theory and a law. What is the difference What was the theory from yesterday? What is an adaptation?

24 Bellwork What evidence from the fossil at right suggests that this dinosaur was a common ancestor to lizards and birds? What is the difference between a variation and an adaptation 3. How does fossil evidence support the theory of evolution? 4. What happens to organisms that cannot adapt to changes in their environment

25 Extinct species research ppt: Summarize your information don’t cut and paste
Slide # What it should have points 1 Title page – your names, period, definition of extinction and how a species becomes extinct 3 2 Name of extinct species #1 with several pictures or illustrations/fossils Describe what present day organisms it may be an ancestor to 4 where, when it lived, what it ate, any predators other interesting info 5 Factors that lead to its extinction – when it went extinct 6 Name of extinct species #2 with pictures/ illustrations/ fossils 7 8 9 You will receive 3 points for creativity/neatness

26 Why do we seem to know more about mammoths than other extinct, prehistoric animals? Size among the mammoths seemed to have varied considerably. To what might this be attributed? What do the shape and size of the mammoth’s tusks indicate that they might have been used for? What is the relationship of the mammoth to the modern elephant? According to some scientists, should the mammals have become extinct? Tusks on the Tundra Besides MacPhee’s theory of a lethal virus, what are the main theories described as to what caused the massive mammalian extinctions featured in this article? Why did MacPhee choose Wrangel Island as the best place to look for evidence of his theory? Hyperdisease Hypothesis What is a megafauna? What were the two unique features of the late Quaternary extinctions noted by MacPhee?

27 Bellwork . Name and describe the 4 parts of Natural Selection
What is evolution? What is the name of the diagram at right? Are the Rodents more closely related to primates or crocodiles. Explain What characteristic do the common ancestors of Birds and fish have in common? .

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