How do you think giraffes acquired a long neck over time? Objective: Understand How Organisms Change Over Time. Key words: Lamarck, acquired, traits, use, disuse. Do Now: How do you think giraffes acquired a long neck over time?

Jean-Baptiste Lamarck Objective: Understand How Organisms Change Over Time. Key words: Lamarck, acquired, traits, use, disuse. Jean-Baptiste Lamarck 1744 - 1829

How Species Acquired New Traits? Objective: Understand How Organisms Change Over Time. Key words: Lamarck, acquired, traits, use, disuse. How Species Acquired New Traits? Original short-necked ancestor Keeps stretching neck to reach leaves higher up on tree Long-necked descendant after many generation

How Species Acquired New Traits? Objective: Understand How Organisms Change Over Time. Key words: Lamarck, acquired, traits, use, disuse. How Species Acquired New Traits?

How Species Acquired New Traits? Objective: Understand How Organisms Change Over Time. Key words: Lamarck, acquired, traits, use, disuse. How Species Acquired New Traits?

How Species Acquired New Traits? Objective: Understand How Organisms Change Over Time. Key words: Lamarck, acquired, traits. How Species Acquired New Traits? Lamarck believed that this occurred through use and disuse. If an animal often used a certain trait or characteristic, that trait would become larger or more pronounced. If the trait went unused, it would no longer develop fully and would become reduced Organisms change over time by inheritance of acquired characteristics

How Species Acquired New Traits? Objective: Understand How Organisms Change Over Time. Key words: Lamarck, acquired, traits. How Species Acquired New Traits?

How Species Acquired New Traits? Objective: Understand How Organisms Change Over Time. Key words: Lamarck, acquired, traits. How Species Acquired New Traits? Because the front claw has been used repeatedly, it becomes larger 1 2 The male crab uses its small front claw to attract mates and ward off predators 3 The acquired characteristics, a larger claw, is then passed on to the crab’s offspring

How Species Acquired New Traits? Objective: Understand How Organisms Change Over Time. Key words: Lamarck, acquired, traits. How Species Acquired New Traits? 2. How did Lamarck explain species acquire new traits? 3. Do you agree or disagree with Lamarck’s explanation of how evolution works? Explain. Species acquire new traits through use and disuse. (False) If an animal often used a certain trait, that trait would become larger. (True) Then, the offspring will inherit the new trait.(False) Disagree. Body traits are determined by DNA. The use or disuse of any trait do not change the DNA.

How Did Giraffes Acquire Long Necks?

Jean-Baptiste Lamarck Objective: Understand How Organisms Change Over Time. Key words: Lamarck, Darwin, acquired, traits, natural selection Jean-Baptiste Lamarck 1744 - 1829 Charles Darwin 1808-1882 Similarities How organisms change over time? The idea of evolution: Species change over time Organisms struggle to survive in their environments The accumulation of small changes could accomplish big results All organisms are related Organisms inherit acquired characteristics Species evolve by natural selection: survival of organisms better adapted to the environment