Questions and Answers
What principle does Lamarckism suggest regarding an organism's use of its organs?
Which of the following accurately reflects a key proposition of Lamarckism?
What is a consequence of the 'Inheritance of Acquired Characters' in Lamarckism?
How did Lamarck explain the elongation of giraffes' necks?
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What underlying concept in Lamarckism explains organisms' progression towards complexity?
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What is a significant outcome of the concept of vestigial wings in flightless birds like the Ostrich?
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How did the environmental changes contribute to the blindness of cave-dwelling animals?
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What fundamental difference exists between Lamarckism and Darwinism regarding species complexity?
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Which of the following statements best describes the evolution of snakes from their ancestors?
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What does the theory of Neo-Lamarckism integrate into its understanding of evolution?
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Study Notes
Lamarckism Overview
- Proposed by Jean-Baptiste de Monet Lamarck (1744-1829).
- Theory asserts that physical changes in an individual during its lifetime are inherited by offspring.
Main Propositions of Lamarck's Theory
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Change Through Use and Disuse:
- Frequent use of an organ leads to its development; infrequent use results in loss.
- Example: Giraffes stretch their necks to reach leaves, causing neck elongation over generations.
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Organisms Driven to Greater Complexity:
- Organisms evolve from simpler forms to more complex ones as they adapt to their environment.
- Lamarck posited the spontaneous generation of life.
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Inheritance of Acquired Characters:
- Characteristics acquired during an individual's life are passed to offspring.
- Example: A blacksmith's strong arms result from work; this trait is inherited by children.
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Effect of Environment and New Needs:
- Environmental changes lead to new needs in organisms, prompting structural changes and habit adaptations.
Examples of Lamarckism
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Evolution of Giraffe:
- Ancestors had short necks. Stretching to reach tall plants led to neck elongation passed to subsequent generations.
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Aquatic Birds with Webbed Toes:
- Believed to have evolved from terrestrial animals adapting to aquatic environments.
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Extinction of Limbs in Snakes:
- Evolved from lizard-like ancestors that had limbs; loss occurred due to environmental adaptations.
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Flightless Birds:
- Ancestors of birds like Ostrich could fly; ceased using wings due to abundant food, leading to vestigial wings.
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Cave Dwellers:
- Ancestors had strong eyesight but lost it over generations in dark environments.
Comparison: Lamarckism vs. Darwinism
- Lamarck focused on the inheritance of acquired traits and organ usage.
- Darwin emphasized natural selection, survival of the fittest, species variation, and extinction.
- Lamarck viewed complexity as a result of use, while Darwin attributed it to adaptation over generations.
- Darwin's theory includes the concept of "transmutation of species" as organisms change in response to environmental shifts.
Neo-Lamarckism
- A reformed version of Lamarckism developed by Giard and Cope, incorporating some feedback from critics.
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Description
Explore the theory of Lamarckism proposed by Jean-Baptiste Lamarck, which suggests that physical changes in individuals during their lifetime can be inherited by their offspring. This quiz covers the main propositions of Lamarck's theory, including the idea of change through use and disuse, and the evolution of organisms towards greater complexity. Test your understanding of this evolutionary concept!
