Ecology Lecture: Predation and Its Impact on Evolution

Introduction to Predation

• Predation is a captivating interaction due to its role in the ecosystem.
• Example: Alaska Brown Bear, apex predator but also feeds on nuts, bugs, berries.
• Humans are considered top predators, yet historically preyed upon by animals, viruses, and bacteria.

Evolutionary Pressures of Predation

• Predation leads to evolutionary adaptations in both predators and prey.
• Examples of adaptations:
  • Grizzly's claws and teeth
  • Wolves' pack hunting
  • Pronghorn's speed
• Results in co-evolution: a process where two species' interactions affect their evolutionary development.

The Scope of Predation

• Predation involves energy transfer in nature and affects evolutionary goals: survival and reproduction.
• Types of predation:
  • Herbivory: E.g., bison eating grass
  • Parasitism: E.g., Hairworms in grasshoppers

Predatory and Prey Adaptations

• Predators:
  • Wolves' smell and teeth
  • Eagles' eyesight and talons
  • Rattlesnakes' heat-sensing and venom
• Prey:
  • Avoidance of detection: Camouflage
  • Avoidance of capture: Speed, safety in numbers
  • Handling prevention: Thorns, chemical defenses
  • Aposematic coloration: Warning colors like those on the fire salamander
  • Mimicry:
    • Mullerian mimicry: Unpalatable species with similar patterns
    • Batesian mimicry: Harmless species mimic the dangerous ones

Historical Context

• Mimicry concepts:
  • Mullerian: Described by Fritz Muller
  • Batesian: Described by Henry Walter Bates, inspired by his South American insect collection.

Future of Predator-Prey Dynamics

• Predation is a driver of continuous evolutionary change.
• Predators and prey engage in an arms race of adaptations.
• Ongoing research into mimicry and adaptation continues to intrigue scientists.

Conclusion

• Predator-prey interactions define the dynamic nature of ecosystems.
• Upcoming exploration on community changes in ecology.