Lecture Notes: Ecological Relationships

Introduction

• Lecture begins with a personal story about sandboxes and discovering antlions.
• Antlions described as insects with a unique lifecycle, having both larvae and adult forms.

Antlions

• Adult Form: Resembles a less cool version of a dragonfly.
• Larvae Form:
  • Known for creating sand pit traps.
  • Ambush predators using mandibles.
  • Inject prey (ants) with enzymes to digest and consume them.
  • Use sand tossing to subdue prey.
  • Also known as 'doodlebugs'.

Ecological Relationships

• Predator-Prey Dynamics:

  • Antlions as predators; ants as prey.
  • Population cycles: Increases and decreases based on food availability.
  • Graph representation shows cyclical population changes.

• Competition:

  • Antlions compete with each other and other species for prey (ants).
  • Example given of jumping spiders also preying on ants.
  • Competition amongst producers, e.g., plants competing for light.

Symbiotic Relationships

• Parasitism:

  • One organism benefits, other is harmed.
  • Example: Fleas and hookworms on a dog.

• Mutualism:

  • Both organisms benefit.
  • Example: Acacia ants and acacia trees.
    • Trees provide shelter and nectar.
    • Ants offer protection against herbivores and competitors.

• Commensalism:

  • One organism benefits, the other is neither helped nor harmed.
  • Example: Barnacles attaching to whales.
    • Barnacles benefit from increased food access.
    • Whales remain unaffected.

Importance of Ecological Relationships

• Influence on species populations.
• Human activity can threaten species, impacting ecological balance.
• Ongoing scientific exploration of new relationships.

Conclusion

• Sign-off with encouragement to stay curious.
• Presented by Amoeba Sisters with a reminder to follow for updates on social media.