LESSON 1

• Zoology


  The study of animals
• Zoology


  • One of the broadest fields in all of science because of the immense variety of animals and the complexity of the processes occurring within animals
  • Zoologists usually specialize in one or more of the subdisciplines of zoology
• There are over 20,000 described species of bony fishes and over 300,000 described species of animals
• Classification of animals


  Attempts at classification as early as 400 BC are known from documents in the Hippocratic Collection
• Aristotle's classification system


  • Recognized a basic unity of plan among diverse organisms
  • Arranged groups of animals according to mode of reproduction and habitat
  • Interested in form and structure and concluded that different animals can have similar embryological origins and that different structures can have similar functions
• Pliny the Elder


  • Compiled four volumes on zoology in his 37-volume treatise called Historia Naturalis
• Galen


  • Dissected farm animals, monkeys, and other mammals and described many features accurately, although some were wrongly applied to the human body
• William Harvey


  • Established the true mechanism of blood circulation
• St. Albertus Magnus


  • Denied many of the superstitions associated with biology and reintroduced the work of Aristotle
• Leonardo da Vinci


  • His dissections and comparisons of the structure of humans and other animals led him to important conclusions
• Andreas Vesalius


  • Considered the father of anatomy; he circulated his writings and established the principles of comparative anatomy
• Carolus Linnaeus


  • Developed a system of nomenclature that is still use today
• Georges Cuvier


  • Devised a systematic organization of animals based on specimens sent to him from all over the world
• Matthias Schleiden and Theodor Schwann


  • Proved that the cell is the common structural unit of living things
• Karl Ernst Von Baer


  • Founder of embryology
• Claude Bernard


  • Developed the study of animal physiology, including the concept of homeostasis
• Charles Darwin


  • Observed the plant and animal life of South America and Australia and developed his theory of evolution by natural selection
• Gregor Mendel


  • First formulated the concept of particulate hereditary factors – later called genes
• Specializations in Zoology


  • Anatomy
  • Cell Biology
  • Ecology
  • Embryology
  • Genetics
  • Histology
  • Molecular Biology
  • Parasitology
  • Physiology
  • Systematics
  • Zoogeography
• Specializations by Taxonomic Group

  • Entomology (study of insects)
  • Herpetology (study of amphibians and reptiles)
  • Ichthyology (study of fishes)
  • Malacology (study of mollusks)
  • Mammalogy (study of mammals)
  • Ornithology (study of birds)
  • Protozoology (study of protozoa)
• Evolutionary Perspective in Zoology


  • Animals share a common evolutionary past and evolutionary forces that influenced their history
  • Evolutionary processes are remarkable for their relative simplicity, yet they have had awesome effects on life-forms
  • These processes have resulted in an estimated 4 to 30 million species of organisms living today
• Only 1.4 million species have been described, many more existed in the past and have become extinct
• Organic evolution


  Change in populations of organisms over time
• Charles Darwin published convincing evidence of evolution in 1859 and proposed a mechanism that could explain evolutionary change
• Karl von Linne's system of naming – binomial nomenclature – has been adopted for animals
• Ecology


  The study of the relationships between organisms and their environment
• Humans depend on animals for food, medicines, and clothing
• Ecological Concerns


  • Global overpopulation
  • Exploitation of world resources
• Global overpopulation


  • At the root of virtually all other environmental problems
  • World population will reach 10.4 billion by the year 2100
  • Disparity between the wealthiest and poorest nations is likely to increase
• Exploitation of world resources

  • Continued use of fossil fuels adds more carbon dioxide to the atmosphere, contributing to the greenhouse effect and global warming
  • Deforestation of large areas of the world results from continued demand for forest products and fuel
• Solutions to ecological problems


  • Understanding basic ecological principles
  • Understanding how matter is cycled and recycled in nature, how populations grow, and how organisms in our lakes and forest use energy
  • Dealing with the problem of human overpopulations