Disruptions to Ecosystems

Ecosystem Disruptions

  • Overview: The lesson focuses on how various factors disrupt ecosystems, including invasive species, human activities, and geological/meterological events.

Evolution and Ecosystem Dynamics

  • Evolution: Characterized by changes in the genetic makeup of populations over time.
  • Adaptations: Traits that provide an advantage in specific environments.
    • Definition: Genetic variations favored by natural selection.
    • Importance: Adaptations increase survival chances and can spread through reproduction.
  • Mutations: Random changes in genetic makeup leading to adaptations.
    • Mutations can increase biodiversity and potentially lead to speciation.

Invasive Species

  • Definition: Non-native species that disrupt local ecosystems by exploiting available resources.
  • Impact:
    • Uncontrolled population growth.
    • Outcompete native species for resources.
    • Example: Water hyacinth and feral cats (Felis catus).
    • Feral cats: Introduced in the 17th century; they kill numerous small animals and contribute to native species decline.

Human Activities

  • Effects on Ecosystems:
    • Habitat changes due to urbanization and resource exploitation accelerate local and global ecosystem changes.
    • Deforestation: Removal of trees affects oxygen production and climate.
    • Example: Irish Potato Famine (1845-1851) caused by a fungal disease spread through trade, resulting in a food crisis and loss of life.

Geological and Meteorological Events

  • Impact of Events: Natural disasters can disrupt habitats and ecosystems significantly.
    • Examples include meteor strikes and volcanic eruptions.
    • These events can accelerate evolution by eliminating certain species and freeing up ecological niches for others.
    • Effects include reproductive isolation and changes in selective advantages.

Key Takeaways

  • An adaptation is a genetic variation that can be favored, leading to population changes over time.
  • Invasive species can maliciously exploit niches, causing resource depletion for native organisms.
  • Human activities contribute to disease spread which can devastate native species.
  • Geological and meteorological events significantly alter ecosystems and species distributions.