Earth's Origin and Composition

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Questions and Answers

What is adaptation in the context of organisms' survival and reproduction?

A process by which organisms evolve into better species

Hearable characteristics that increase an organism's ability to survive and reproduce

The ability of an organism to change its environment

Heritable characteristics that increase an organism's ability to survive and reproduce (correct)

What determines the fitness of an organism in its environment?

The number of adaptations an organism has

The presence of generalist species in the ecosystem

The ability of an organism to migrate to a new environment

How well an organism can survive and reproduce in its environment (correct)

What is the main driver of the process of natural selection?

Mutations in the genome of an organism

The variation in adaptations among individuals in a population (correct)

The intentional selection of traits by humans

The random survival of individuals in a population

What is a niche in the context of ecology?

The role an organism plays in a community, including physical and environmental conditions Signup and view all the answers

What is a characteristic of generalist species?

They have a broad niche that is easily adaptable to many environmental conditions Signup and view all the answers

What is a misconception about natural selection?

It makes organisms 'better' Signup and view all the answers

What is the hottest layer of the Earth?

Core Signup and view all the answers

What is the process of breaking down rocks and minerals into smaller particles?

Weathering Signup and view all the answers

What is the theory that explains how Earth's continents were once joined together and have since drifted apart?

Continental Drift Theory Signup and view all the answers

What is the process of carrying away small particles by wind, water, or ice?

Erosion Signup and view all the answers

What is the term for the time required for half of the radioactive atoms in a sample to decay?

Half-life Signup and view all the answers

What is the process of forming sediment layers through the deposition of particles carried by water?

Sedimentation Signup and view all the answers

What is the term for the movement of the Earth's lithosphere divided into huge plates?

Plate Tectonics Signup and view all the answers

What is the theory that explains how species adapt to their environment through natural selection?

Darwin's Theory Signup and view all the answers

Study Notes

Earth's Structure and Composition

Earth has three main layers: Crust (thin, solid outer layer), Mantle (solid shell from crust to 2900 km deep), and Core (hot, metal center)
Lithosphere: combination of crust and top layer of mantle
Geosphere: all three layers together

Early Earth Atmosphere and Hydrosphere

Early atmosphere had minimal O2, mainly CO2, water vapor, and N2
Small amounts of CO, H2S, HCN were present
Water vapor cooled and condensed to form oceans, lakes, and the hydrosphere

Plate Tectonics and Geosphere Dynamics

Lithosphere divided into huge plates with varying amounts of continental and oceanic crust
Plate boundaries: Divergent (move apart), Convergent (move together), Transform (slide past each other)
Mid-Ocean Ridges: upwelling in mantle brings hot rock to surface
Subduction Zones: older part of ocean floor sinks, water drives out, and rock melts
Mountain Building: two plates collide, oceanic crust sinks, and continental crust forms mountain ridges

Continental Drift Theory

Continents were once joined as Pangaea and have since drifted apart
Evidence: fit of continents, matching geological features, similar fossil distributions, and ancient climates found in rocks

Weathering and Erosion

Weathering: physical and chemical processes breaking down rocks and minerals into smaller particles
Erosion: small particles carried away by wind, water, or ice (e.g., salt minerals into oceans)
Formation of sediment layers: particles carried by water and deposited in larger bodies of water

Sedimentary Rock and Fossils

Sedimentary rock important in studying life history
Law of Superposition: youngest rocks on top, oldest on bottom
Half-life and absolute (radiometric) dating help determine age of samples

Evolution and Natural Selection

Charles Darwin's Theory: Natural Selection
Variation and Adaptation: inherited variation helps individuals survive and reproduce in their environment
Adaptation: heritable characteristics increasing organism's ability to survive and reproduce
Survival of the Fittest: fitness affected by adaptations
Natural Selection: process by which organisms with suitable variations survive and leave offspring
Environment influences fitness, varying among individuals
Every species occupies its own niche (role in a community with physical and environmental conditions)

Species Niches

Generalist: species with broad niche, adaptable to many environmental conditions
Specialist: species with narrow niche, specialized to specific conditions
Examples: Raccoons (generalist), Specialists (e.g., pandas)

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Description

Learn about the formation and structure of our planet, including the 3 main layers, atmosphere, and the dynamic geosphere. Discover the early atmosphere's composition and the creation of the hydrosphere.