Introduction to Zoology & Scientific Method

Zoology: Definition & Purpose

  • Scientific study of animal diversity: structure, function, development, nutrition, health, heredity, evolution
  • Aims:
    • Understand natural world
    • Protect environment
    • Cultivate analytical & observational skills

Major Subdivisions

  • Anatomy ("to cut")
    • Gross/Morphology
    • Comparative
    • Human
    • Developmental (Embryology)
    • Microscopic: Cytology, Histology
  • Physiology
    • Cellular
    • Comparative
    • Endocrinology
    • Neurology
  • Genetics — genes, heredity, variation
  • Ecology — organism–environment interactions
  • Zoogeography — animal distribution on Earth
  • Paleontology — past life via fossils
  • Taxonomy — systematic classification
  • Evolution — origin & diversification of forms

Specialized Zoological Fields

  • Protozoology, Ichthyology, Entomology, Helminthology, Conchology, Herpetology
  • Malacology, Carcinology, Parasitology, Mammology, Ornithology

Brief History & Key Figures

  • Aristotle 384–322\,BC — Father of Zoology
  • Galen 129–216\,AD — nervous system; blood in arteries
  • Vesalius 1514–1564 — modern anatomy
  • Harvey 1578–1657 — blood circulation
  • Jansen 1590 — compound microscope
  • Hooke 1635–1703 — cell discovery
  • Leeuwenhoek 1632–1723 — bacteria, protozoa, sperm
  • Linnaeus 1707–1778 — taxonomy
  • Cuvier 1769–1832 — paleontology
  • Von Baer 1792–1876 — embryology
  • Hunter 1737–1821 — pathological anatomy
  • Koch 1843–1910 — anthrax, tuberculosis bacteria
  • Pasteur 1822–1895 — rabies & anthrax vaccines, germ theory, pasteurization
  • Jenner 1749–1823 — cowpox → smallpox immunity

Science & Its Process

  • Science: organized knowledge from studying the natural world
  • Relies on empirical, testable, reproducible evidence

Core Steps in Scientific Method

  • Observation — use senses to note phenomena
  • Question/Problem — define based on observations
  • Hypothesis — tentative, testable \textit{if–then} statement
  • Experiment — controlled test with:
    • Independent variable (manipulated)
    • Dependent variable (measured)
    • Control variables & control group for comparison
    • Only one variable tested for a valid experiment
  • Data — quantitative or qualitative; must be organized (tables, graphs, charts)
  • Analysis — judge reliability; support or refute hypothesis
  • Conclusion — summarizes findings; should be retestable
  • Retest — verify results through repeated trials
  • Communication — publish, present; enables peer verification & cumulative progress
  • Theory — broad explanation formed after repeated support of related hypotheses

Key Experimental Principles

  • Sampling represents populations
  • Multiple trials increase reliability
  • Scientists must remain unbiased; report only tested, verified data
  • Scientific inquiry is iterative; quick answers rare