Topic 3 Charles Darwin (BSES 1A)
Page 1: Guide Questions
Proposed Theory: Theory of Evolution
Main Concepts:
Natural selection is the mechanism of evolution.
Organisms with favorable traits survive and reproduce.
Species change over time through descent with modification.
Prevailing Beliefs Before Theory:
Species are fixed and do not change.
The Earth is relatively young.
Organisms were created in their current forms by divine intervention.
Controversies of the Theory:
Challenges religious beliefs and creationist views.
Questions the notion of the distinct separateness of species.
Implications on society’s understanding of humanity's place in nature.
Social Transformation:
Influences scientific thinking and biological studies.
Promotes a new understanding of life and biodiversity.
Affects social, political, and philosophical views on human origins.
Page 2: Theory of Evolution by Natural Selection
Important figures: Charles Darwin (1809-1882)
Key Locations: Galapagos Islands (Hood, Isabela, Santa Cruz)
Page 3: Definition of Evolution
Evolution: Change over time from ancient organisms to modern forms.
Scientific Theory: A well-supported explanation of natural phenomena.
Page 4: Voyage of the Beagle
Year: 1831-1836
Captain: Charles Darwin
Ship: H.M.S. Beagle
Purpose: Voyage around the world for scientific discovery.
Page 5: Observations of Darwin
Darwin made various observations on species diversity and adaptation over his five-year journey.
Page 6: Evidences of Evolution
Fossil Record: Provides historical evidence of extinct species.
Geographic Distribution: Similar environments host similar organisms.
Homologous Structures: Close similarities in embryonic development indicate common ancestry.
Page 7: Fossil Evidence
Extinct organisms, such as giant armadillos and sloths, show evolutionary links.
Page 8: Fossils and Living Organisms
Darwin collected fossils resembling modern species, uncovering questions about extinct species' relations to living things.
Page 9: Galapagos Islands
Diverse environments contribute to species adaptation; lower islands are barren while higher islands have rich vegetation.
Page 10: Finch Species Adaptation
Finch species adapted to environments with varying diets reflecting their beak shapes.
Page 11: Galapagos Wildlife
Darwin observed tortoise shell variations across islands, indicating specific adaptations.
Page 12: Key Points of Natural Selection
Favorable traits lead to survival and reproduction, enhancing those traits across generations.
Page 13: Adaptation Through Natural Selection
Populations adapt to their environments through inherited changes over time.
Page 14: Descent with Modification
Species change, leading to new species from a common ancestor.
Page 15: Tree of Life
Species are related through common ancestry; changes accumulate over long periods.
Page 16: Influences on Darwin's Thinking
James Hutton: Proposed Earth is shaped by slow geological processes.
Charles Lyell: Argued Earth's features are subject to gradual change; inspired Darwin to link life changes to geological timescales.
Page 17: Lamarck’s Theory of Evolution
Suggested characteristics can be acquired and passed to offspring (e.g., giraffe's necks).
Page 18: Population Growth Impact
Thomas Malthus: Population growth leads to resource scarcity; inspired Darwin to apply this to animals.
Page 19: Publication of "Origin of Species"
Alfred Russel Wallace's essay inspired Darwin to publish his findings on evolution.
Page 20: Natural and Artificial Selection
Natural Variation: Variations among individuals.
Artificial Selection: Humans choose variations that are beneficial.
Page 21: The Struggle for Existence
Members of species compete for essentials; natural selection favors suitable individuals.
Page 22: Descent Relationships
Organisms descend with modifications and share common ancestors.
Page 23: Summary of Darwin's Theory
Traits vary among individuals; more offspring are produced than can survive.
Page 24: Final Summary of Darwin's Theory
Best-adapted individuals survive; species evolve and are linked by common ancestry.