Adaptations, Populations, Ecosystems, and Earth’s Dynamics

Posted on Feb 16, 2025 in Geology

Adaptations to Sunlight

Not all species need the same amount of light; therefore, they adapt their vision to the conditions they require. For example, owls have adapted to see at night.

Adaptations to Salt Concentration

Osmosis controls the water that enters and leaves the body. If there is too much salt, water leaves the organism, causing death. If the salt concentration is too low, too much water enters the body, also resulting in death.

Adaptations to Lack of Oxygen

Low oxygen levels cause problems. Organisms need to adapt to receive the right amount of oxygen.

Adaptation to Lack of Food

Organisms adapt by storing energy reserves in their bodies, storing food in hidden places, or migrating to find food.

Types of Populations

  • Invertebrate colonies: Connected and related to each other, reproducing asexually.
  • Family groups: Originate from a pair of animals whose offspring stay together within the family unit.
  • Caste system of social insects: Descend from one mother.
  • Social groups: Tend to live together, sometimes temporarily.

Population Growth

  • Decreasing population: Characterized by a larger post-reproductive age group.
  • Increasing population: Characterized by a larger reproductive age group.
  • Population that will increase: Characterized by a larger pre-reproductive age group.

Population Growth Strategies

  • R strategies: Many offspring, but with little parental care.
  • K strategies: Few offspring, but with significant parental care.

Interspecific Relationships Within Communities

  • Predation: One organism kills and feeds on another.
  • Competition: Organisms compete for the same resources; this can be interspecific (between different species) or intraspecific (within the same species).
  • Parasitism: One organism benefits at the expense of another. This can be ectoparasitism (external) or endoparasitism (internal).
  • Social parasitism: A type of parasitism specific to social animals.
  • Commensalism: One organism benefits, and the other is neither harmed nor helped.
  • Mutualism: Both organisms benefit.
  • Symbiosis: A close, long-term interaction between two different species.

The Cycle of Matter

Matter is classified as organic and inorganic. Inorganic substances like water, minerals, and CO2 are transformed into organic matter by autotrophs through photosynthesis. Herbivores obtain organic matter by feeding on plants, and carnivores obtain it by feeding on other animals. Bacteria and fungi transform organic compounds back into inorganic compounds. These inorganic compounds are then used by autotrophs, and the cycle begins again.

Trophic Levels in the Food Chain

  • Producers: Convert inorganic matter into organic matter.
  • Primary consumers: Feed on producers.
  • Secondary consumers: Feed on primary consumers.
  • Tertiary consumers: Feed on secondary consumers.
  • Decomposers: Break down organic matter into inorganic matter.

Terrestrial Ecosystems

  • Atlantic forest: Characterized by abundant rainfall and deciduous trees.
  • Mediterranean forest: Characterized by less rainfall.

Aquatic Ecosystems

  • Fluvial ecosystems: River ecosystems.
  • Wetlands: Important stop-off points for migrating birds.
  • Coastal ecosystems: Areas where land meets the sea.
  • Marine ecosystems: Ocean ecosystems.

Terrestrial Biomes

  • Tundra: Low temperatures year-round, little rain.
  • Taiga: Low temperatures year-round, short summers, moderate precipitation.
  • Deciduous forest: Moderate temperatures.
  • Mediterranean forest: Mild temperatures in winter, high temperatures in summer, little rain.
  • Desert: Extreme temperatures, little rain.
  • Steppes and savannahs: High temperatures, long dry seasons, short rainy seasons.
  • Tropical and equatorial forest: High temperatures and humidity year-round.

Marine Biomes

  • Plankton: Microscopic organisms that drift in the water.
  • Nekton organisms: Organisms that actively swim in the water.
  • Benthic organisms: Organisms that live on the seabed.

Human Activity

Human activities impact the environment through pollution, overexploitation, uncontrolled construction, and waste production.

Earth’s Internal Layers

Compositional Layers

  • Crust: Made up of less dense rocks, rich in silicon and aluminum.
  • Mantle: Composed of peridotite and magnesium.
  • Core: Primarily composed of iron.

Physical Layers

  • Lithosphere
  • Asthenosphere
  • Lower Mantle
  • Core

Seismic Discontinuities

Types of Seismic Waves

  • Primary waves (P): Fastest waves, travel through solids and liquids.
  • Secondary waves (S): Slower waves, travel only through solids.

These waves are recorded using a seismometer. Two main types of boundaries exist: the Mohorovicic discontinuity and the Gutenberg discontinuity.

Continental Drift Theory

Supported by paleontological evidence, geological evidence, and paleoclimatic evidence.

Types of Plate Boundaries

  • Divergent boundaries: Plates move apart.
  • Convergent boundaries: Plates come together.
  • Transform boundaries: Plates slide past each other.

Dip-Slip Faults

  • Normal
  • Reverse
  • Vertical fault

Strike-Slip Faults

  • Left-lateral or sinistral tear fault
  • Right-lateral or dextral tear fault