Presentation on theme: "Ch. 14.1: Darwin developed a Theory of Evolution"— Presentation transcript:
1 Ch. 14.1: Darwin developed a Theory of Evolution ObjectivesSummarize ideas from Darwin’s time that influenced his work.Identify some key observations from Darwin’s voyage that led to his theory.Describe the two main points of Darwin’s theory.VocabularyEvolutionAdaptationDescent w/ ModificationNatural selection
2 What do you know about the Theory of Evolution? Do you agree or disagree?Humans evolved from apes.
4 What do you know about the Theory of Evolution? Do you agree or disagree?2. Individual organisms can evolve.
5 What do you know about the Theory of Evolution? Do you agree or disagree?3. Populations will evolve adaptations that they need to be successful.
6 What do you know about the Theory of Evolution? Do you agree or disagree?4. Evolution can happen in one life time.
7 What do you know about the Theory of Evolution? Do you agree or disagree?5. Evolution can only happen over millions of years.
8 What do you know about the Theory of Evolution? Do you agree or disagree?6. Humans have stopped evolving.
9 Old Ideas Darwin’s Influences Before Darwin Species are fixed or permanentEarth was less than 10,000 years old (and unchanging)Darwin’s InfluencesLyell: Study of fossils and rock record … Earth is much older than 10,000 and Earth CHANGES.Farmers: Selective breeding can change species.Malthus: Economist (Famine & disease result when population are bigger than resources. Selective pressure)Lamarck (1800): Inheritance of Aquired Characteristics (Organisms can adapt!)
10 Lamarck’s Theory of Evolution Inheritance of Acquired CharacteristicsBased on 3 IdeasDesire (will) to changeUse and DisusePassing on acquired traitsIntroduces idea that populations CAN EVOLVE or CHANGE (correct)Knew NOTHING about GENES/GENETICS.
11 Charles Darwin Proposed THEORY OF EVOLUTION. 1. Descent with ModificationChange in species over time.Modern organisms descend from ancient.Adaptations are acquired in response to changes in habitatAdaptation: Inherited trait that improves ability to survive & repro.NATURAL SELECTION = mechanismWell suited individ. SURVIVE & REPRO. More offspring (pass genes on)
12 Darwin’s Observations Voyage on the BEAGLEGalapagos:Unique organisms - similar to, but different from plants on nearest mainland.Each island had in chain had some different species.Mainland species had changed after they colonized the islands and adapted to new environments.Wrote: On Origin of Species (w/ Wallace), 1858
14 Evolution by Natural Selection Wild species show variations (due to genetics)High birthrates & limited resources cause competition (everyone can’t survive & thrive)Individuals well-suited to enviro. SURVIVE & REPRO. (SURVIVAL OF FITTEST)Larger portion of each new generation will have favorable variation.Over long periods of time, small changes accumulate (Adaptation occurs!)6. Environment “chooses” favored traits (Selective Pressure)
15 Peppered Moths: Natural Selection in Action Which one is best “fit” for the environment?What happened?Relative frequency of alleles for color changed in the gene pool for the population.Why?Change in selective pressure
16 Self QuizYou hear someone remark that evolution says we come from monkeys. Educate them with your response.2. Discuss 1 influence (person) on the development of Darwin’s theory. Explain HOW this influence relates to Darwin’s EVOLUTION.
17 Self Quiz What did Lamarck get right? What did he get wrong? 4. 2 Sentence Summary: What is evolution and how does it work?