Zoology

• Zoology is the study of animals, including the scientific study of their behavior, structure, physiology, classification, and distribution
• Zoology is one of the broadest fields in science due to the immense variety of animals and the complexity of processes occurring within animals
• There are more than 20,000 described species of bony fishes and over 400,000 described species of beetles
• Subdisciplines of Zoology:

  • Anatomy: Study of the structure of entire organisms and their parts
  • Cytology: Study of the structure and function of cells
  • Ecology: Study of the interaction of organisms with their environment
  • Embryology: Study of the development of an animal from the fertilized egg to birth or hatching
  • Genetics: Study of the mechanisms of transmission of traits from parents to offspring
  • Histology: Study of tissues
  • Molecular biology: Study of subcellular details of structure and function
• • Parasitology: Study of animals that live in or on other organisms at the expense of the host
  • Physiology: Study of the function of organisms and their parts
  • Systematics: Study of the classification of, and the evolutionary interrelationships among, animal groups
• Specializations in Zoology:

  • Entomology: Study of insects
  • Herpetology: Study of amphibians and reptiles
  • Ichthyology: Study of fishes
  • Mammalogy: Study of mammals
  • Ornithology: Study of birds
  • Protozoology: Study of protozoa
• Taxonomy is the process of naming and classifying animals and plants into groups within a larger system, according to their similarities and differences
• Taxonomy is derived from the Greek words taxis ("arrangement") and nomos ("law")
• Taxonomy sets up arrangements of the kinds of plants and animals in hierarchies of superior and subordinate groups
• 8 levels of Classification (The Taxonomic Hierarchy):

  1. Domain: Includes Bacteria, Archaea, and Eukarya

  2. Kingdom: Recognizes six Kingdoms including Eubacteria, Archaebacteria, Plantae, Animalia, Fungi, and Protista

  3. Phylum: Taxonomic ranking that comes third in the hierarchy of classification, with known phyla including Animals, Plants, Fungi, Protista, Bacteria, and Archaea
• Class:

  • A class combines a distinct grade of organization with a distinct type of construction or layout of organ systems
  • There are 108 different classes in the kingdom Animalia, including Mammalia, Aves, and Reptilia
  • Linnaeus proposed classes of Animalia based on attributes like the arrangement of flowers
• Linnaeus' classes of plants were based on attributes like the arrangement of flowers rather than relatedness
• Today's classes of plants are different than the ones Linnaeus used
• Classes are not frequently used in botany
• Order is more specific than class
• Some of Linnaeus' orders are still used today, such as Lepidoptera (the order of butterflies and moths)
• There are between 19-26 orders of Mammalia, depending on how organisms are classified
• Some orders of Mammalia are Primates, Cetaceans (whales, dolphins, and porpoises), Carnivora (large carnivores/omnivores), and Chiroptera (bats)
• Family is more specific than order
• Some families in the order Carnivora are Canidae (dogs, wolves, foxes), Felidae (cats), Mephitidae (skunks), and Ursidae (bears)
• Carnivorans are split into two suborders: Feliformia ("catlike") and Caniformia ("doglike")
• The most common modern classification scheme divides the Carnivora into sixteen living and a number of extinct families
• The final two categories are genus and species
• The genus and species that an organism belongs to are how an organism receives its scientific name
• This naming system is called 'binomial nomenclature' and was invented by Carl Linnaeus
• An easy way to remember these terms is to note that genus refers to the "generic" name, and species refers to the "specific" name
• Approximately 510,000 species were known by the end of 2016, increasing at some 2,500 per year
• Taxon: A population of organisms that has been grouped together by taxonomists
• Binomial nomenclature: A two-part system of naming species; species are referred to by their genus name followed by their species name
• Taxonomic hierarchy: An ordered group of taxonomic ranks used to classify organisms from general to specific
• Taxonomic rank: A level of a group of organisms in a taxonomic hierarchy
• Evolutionary processes are remarkable for their relative simplicity
• These processes have resulted in an estimated 4 to 100 million species of animals living today (Over 1 million described)
• Zoologists must understand evolutionary processes to understand what an animal is and how it originated
• Organic evolution is the change in the genetic makeup of organisms over time
• Charles Darwin published convincing evidence of evolution in 1859
• The mechanism proposed by Darwin has been confirmed and serves as the nucleus of our broader understanding of evolutionary change
• Ichthyology is the study of fishes
• Ichthyologists work to understand the structure, function, ecology, and evolution of fishes
• Cichlids are fish from the family Cichlidae in the order Cichliformes