Darwin’s Theory Chapter 11 Lesson 2

Essential Questions WHAT WAS DARWIN’S HYPOTHESIS? What is natural selection?

Vocabulary Adaptation Scientific theory Trait Natural selection The following vocabulary words can be found highlighted in your book on pages 385-393. Write their definition in your notes next to the picture of this slide. Adaptation Scientific theory Trait Natural selection variation

What was Darwin’s hypothesis? in 1831 Darwin set sail on a five year trip around the world. He was a naturalist or someone who observes and studies nature. Darwin made the following observations: Diversity- Darwin was amazed at the diversity of living things he saw. He wondered why they were so different from those in England.

What was Darwin’s hypothesis? Fossil size- Darwin observed fossils that resembled the bones of living sloths but that were much larger.

What was Darwin’s hypothesis? Characteristics of Galapagos organisms- Darwin noticed differences between the Galapagos iguanas and the south American iguanas. Look at page 386 of your book and complete the “comparing iguanas” section at the bottom.

What was Darwin’s hypothesis? Characteristics of Galapagos organisms- Darwin also noticed differences among organisms in the different Galapagos islands. For example, tortoises from one island had a dome shaped shell and tortoises from another island had a saddle shaped shell. He found that he could tell which island the turtle came from just by looking at its shell.

What was Darwin’s hypothesis? Characteristics of Galapagos organisms- Darwin also noticed that the birds looked different on each island in the Galapagos. While they were all finches, they all had different beak shapes. Turn to page 387 of your book. Read and complete “interactive art” Discuss with your group. You will have 10 minutes

What was Darwin’s hypothesis? Darwin’s hypothesis was that species change over time and become adapted to new conditions.

+ = Artificial selection In artificial selection only organisms with a desired trait are bred. + = Turn to page 388 and complete the “APPLY IT” section at the bottom. You may discuss with your group. You will have 5 Minutes.

Artificial selection Does artificial selection support Darwin’s hypothesis? Discuss with your group and answer in your notes. Remember- Darwin hypothesized that species change over time and become adapted to new conditions.