Section 2 How Does Evolution Happen? Chapter 7 Bellringer Upright walking, hair, fingerprints, binocular vision, and speech are all traits that almost all humans have in common. List the advantages and disadvantages of each trait. Do you think the advantages are greater than the disadvantages? Why or why not?

Section 2 How Does Evolution Happen? Chapter 7 Objectives List four sources of Charles Darwin’s ideas about evolution. Describe the four parts of Darwin’s theory of evolution by natural that gradual processes had changed the Earth’s surface over selection. Relate genetics to evolution.

Chapter 7 Charles Darwin Section 2 How Does Evolution Happen? Chapter 7 Charles Darwin Darwin’s Excellent Adventure After Charles Darwin graduated from college, he served as naturalist on a ship called the HMS Beagle. During a voyage around the world, Darwin collected thousands of plant and animal samples.

Chapter 7 Charles Darwin Section 2 How Does Evolution Happen? Chapter 7 Charles Darwin Darwin’s Finches Darwin noticed that the finches of the Galápagos Islands were a little different from the finches in Ecuador. And the finches on each island differed from the finches on the other islands.

Chapter 7 Darwin’s Thinking Section 2 How Does Evolution Happen? Chapter 7 Darwin’s Thinking Ideas About Breeding The process in which humans select which plants or animals to reproduce based on certain desired traits is called selective breeding.

Chapter 7 Darwin’s Thinking Section 2 How Does Evolution Happen? Chapter 7 Darwin’s Thinking Ideas About Population Only a limited number of individuals survive to reproduce. Thus, there is something special about the offspring of the survivors.

Chapter 7 Darwin’s Thinking Section 2 How Does Evolution Happen? Chapter 7 Darwin’s Thinking Ideas About Earth’s History Darwin had begun to think that species could evolve over time. It became clear to Darwin that Earth was much older than anyone had imagined.

Darwin’s Theory of Natural Selection Section 2 How Does Evolution Happen? Chapter 7 Darwin’s Theory of Natural Selection What Is Natural Selection? Darwin proposed the theory that evolution happens through a process that he called natural selection. Individuals that are better adapted to their environment survive and reproduce more successfully than less well adapted individuals. Genetics and Evolution Today, scientists have found most of the evidence that Darwin lacked. They know that variation happens as a result of differences in genes.

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