Evolution powerpoint
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1. The scientific theory of evolution is supported by multiple lines of evidence, including the fossil record, comparative anatomy, and observed changes over time. 2. Early evolutionary thinkers like Lamarck proposed different mechanisms of evolution than what is accepted today, such as the inheritance of acquired traits based on environmental needs. 3. Modern evolutionary synthesis incorporates Darwin's idea of descent with modification through natural selection acting on random genetic mutations and variations that arise during reproduction. Traits that increase reproductive success and survival become more common in populations over generations.
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Evolution powerpoint
- 1. EvolutionSC.912.L.15.1 Explain how the scientific theory of evolution is supported by the fossil record, comparative anatomy, comparative embryology, biogeography, molecular biology, and observed evolutionary change
- 2. Darwin wasn’t the only one Lamarck Changes in a phenotype occur because of an environmental need Giraffe Modifications were passed onto the next generation Inheritence “need” was dictated by environmental change and that change involved movement towards perfection
- 3. Now we know No evidence that changes in environment can initiate changes in organisms that can be passed on to future generations Change originates in the process of gamete formation Environment does not create these variations it determines the survival of these variations
- 4. “Decent with Modification”Organic Evolution: “Decent with modification” - Charles Darwin Species change gradually through adaptation. Chance FLASH CARD ALERTADAPTATION: A single individual has a random mutation/trait that creates a change in phenotype, which increases the organism’s chance of successful reproduction. Leads to: NATURAL SELECTION
- 5. FLASH CARD ALERT: NATURAL SELECTION: The adapted individual is able to survive and reproduce in the new environment better than othersThen: The adapted individual reproduces, creating more individuals with the same adaptations.These adaptations become predominant in the population, thus altering the genetic makeup of the entire population… OR…A new species arises that co-exists with the ancestor
- 6. THE STEPS OF EVOLUTION1. Random mutation. A single individual has a random mutation/trait that is beneficial in its environment.2. Natural selection: The adapted individual is able to survive and reproduce in the new environment better than others3. Reproduction of adaptive trait: The adapted individual reproduces, creating more individuals with the same adaptations.
- 7. 4. These adaptations become predominant in the population, thus altering the genetic makeup of the entire population… OR…
- 8. 5. A new species arises that co-exists with the ancestorFlightless Birds: Penguin
- 9. Random Mutation: Can be advantageous (adaptation) neutral, or maladaptive Adaptation: characteristics that increase the potential of an organism to successfully reproduce in a specified environment Adaptations are characteristics that increase an individual's evolutionary fitness.
- 10. FLASH CARD ALERT: EVOLUTIONARY FITNESS: measure of the capacity for successful reproduction in a given environment relative to others of that same species.
- 12. How Natural Selection WorksAll organisms have a far greater reproductive potential than is ever realizedStarfishStruggle of survival: Not enough resources to go aroundChanges in the environment: climate change, food shortages, environmental stressors. Inherited Variations existGenetic mutation & recombination
- 13. These genetic changes MAY BE an advantage Chance. Because individuals with maladaptive traits are less likely to reproduce the maladaptive traits become less frequent and are eventually eliminated