Evolutionary Principles of Animal Behaviour

Introduction to Animals

• Definition Contexts: Animals can be defined in various contexts:
  • Textbook definitions
  • New Zealand legal definitions (NZ Animal Welfare Act 1999)
  • Animal ethics perspectives
  • Biological context (most life forms on Earth are not vertebrates)

Characteristics of Animals

• Multicellular Organisms:

  • Animals are composed of more than one cell.

• Heterotrophic:

  • Animals cannot produce their own food through carbon fixation and must derive nutrition from other organic sources (plants or other animals).

• Eukaryotic Cells:

  • Animal cells are eukaryotic, meaning they contain a membrane-bound nucleus and lack cell walls that provide structural support.

• Development from Embryonic Layers:

  • Tissues in animals develop from embryonic layers, which later form various adult body parts.

New Zealand Animal Welfare Act 1999

• Definition of 'Animal' (according to the Act):
  • Includes live representatives from the animal kingdom such as:
  • Mammals
  • Birds
  • Reptiles
  • Amphibians
  • Fish (both bony and cartilaginous)
  • Mollusks like octopus and crab
  • Excludes humans.

Evolutionary Tree of Life

• Major Groups of Animals:
  • Deuterostomia: Includes Chordata (vertebrates), Echinodermata, and others.
  • Protostomia: Includes Arthropoda, Mollusca, and many others.
  • Most animal species have diverged from common ancestors over approximately 700 million years.

Classification and Diversity

• Around 3.7% of animal species are vertebrates.
• Examples of animal groups with the number of species:
  • Arthropoda ~1,500,000 species
  • Mollusca ~8,500 species
  • Annelida ~12,000 species
  • Cnidaria ~9,000 species

Animal Behavior

• Behavior Definition:

  • Actions taken by multicellular eukaryotes exhibited in response to stimuli, controlled by muscles and glands through the nervous system.

• Types of Behaviour:

  • Individual actions (e.g., locomotion, grooming, communication).
  • Collective responses to both internal and external stimuli.

• Lab Activities for Understanding Behaviour:

  • Analyzing the effect of temperature on movement.
  • Assessing the influence of an observer on behavior measurements.
  • Exploring genetics' contribution to behavior.
  • Observations on food choice and alternative methods for recording behaviour.