10.4 Evidence of Evolution SPONGE Look back in your notes from Thursday. Please write a paragraph...

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10.4 Evidence of Evolution

SPONGE

Look back in your notes from Thursday. Please write a paragraph describing what Darwin learned from the animals that he observed on his voyage. (Think adaptations and variations)

What are adaptations?

Is a physical difference in ONE individual in a group an adaptation or a variation?

OBJECTIVE

Today we will create a double bubble map comparing and contrasting the homologous structures of a bird vs. a whale.

10.4 Evidence of EvolutionSet up Cornell Notes on pg. 19

•Topic: 10.4 Theory of Evidence of Evolution

•Essential Question:

1.How can a bat’s wing be considered a homologous structure AND an analogous structure?

2.1 Atoms, Ions, and Molecules10.4 Evidence of Evolution

1. How can a bat’s wing be considered a homologous structure AND an analogous structure?

Understanding that structural patterns are clues to the history of a species is important because some of Darwin’s best evidence for evolution came from comparing the body parts of different species.

Why is this important?

STANDARDS

8.d- Students know reproductive or

geographic isolation affects speciation

7.3c- Students know how independent lines of evidence from geology, fossils, and comparative anatomy provide the bases for the theory of evolution

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

1. Fossils- are the preserved remains of animals, plants, and other organisms from the past.

Evidence of Evolution:

• Fossils in older layers are more primitive (simple) than those in the upper layers

• Evidence for change over time• The fossil record supports

Darwin’s concept of Decent with modification

• Specific conditions are needed for fossilization.• Only a tiny percentage of living things became fossils.

• Relative dating estimates the time during which an organism lived.– It compares the placement

of fossils in layers of rock.– Scientists infer the order in

which species existed.

Fossil evidence of evolution of Hominid Skull

The term "hominid" may refer to "humans and relatives of humans closer than chimpanzees".[2] In this usage, all hominid species other than Homo sapiens are extinct

• 2. Geography:

– Darwin saw that island finches looked like, but were not identical to, species on the S. American Continent

– Different ecosystems, favored different traits

• 3. Embryology (study of embryos):

– The similar features of embryos in very different organisms suggests evolution from a distant common ancestor

Anatomy of an embryo

Adult barnacleAdult crab

– identical larvae, but different adult body forms– similar embryos, but look and behave very differently

Darwin studied the embryos of crabs and barnacles:

Look for the similarities of the embryos

• 4. Anatomy:

– Homologous structures are similar in structure but different in function

• Some of Darwin’s best evidence came from comparing body parts of different species

–The similarities in anatomy in different species offers strong evidence for a common ancestry

–It would be unlikely for many species to have such similar anatomy if each species evolved separately.

1. Identify each animals’ anatomical structure (by coloring like bones the same color)2. Identify each animals anatomical function

Homologous Structures:

All have a similar structure (the bones are similar), but their functions are different. (Some for walking, some for flying, some for swimming)

Homologous Structures:

Studying, anatomy gives us clues to the history of a species

• Vestigial Structures: Are remnants of organs or structures that had a function in an early ancestor

Points to Ponder

• Compare these wings.• They are both used to _______• Are the structures the same?

Points to Ponder

• Suppose two organisms have similar needs caused by the environment, for example two different organisms needing to fly…– Both can develop similar adaptations using

different body parts (analogous structures)

– Analogous structures are NOT evidence of a common ancestor!!!!!!

– Analogous structures have a similar function, but are NOT similar in origin

**Identify each animals’ anatomical structure vs. function

All function the same way (they are all used for flying), but their structures are different

**Identify each animals’ anatomical structure vs. function

Chitin

Bone and feathers

Bone and SkinChitin

SPONGE

Please open your study guides to page 105 and complete it.

For those of you who forgot it….

Give examples of each

Evidence for evolution in Darwin’s time came from

several sources

Fossils: Geography:

Embryology: Anatomy:

10.4 Evidence of Evolution SPONGE Look back in your notes from Thursday. Please write a paragraph...

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