Presentation on theme: "Classification of Animals. Review Biology is the study of life… So what makes something living?"— Presentation transcript:
Classification of Animals
Review Biology is the study of life… So what makes something living?
All living things must: 1. Be made up of at least 1 cell that contains genetic material (DNA) 2. Grow (increase in size, mature, develop, etc.) 3. Metabolize (have a need and use for energy) 4. Respond to stimuli
That’s all fine and good, but when do we get to the animals? Zoology-the study of animals Two Major Categories: Vertebrates-have a backbone Invertebrates-do not have a backbone Vertebrate or Invertebrate?
Characteristics of Animals Multicellular Eukaryotes (cells with nucleus & organelles) Cells do not have a cell wall or chloroplast Ingestive heterotrophs (take in food and internally digest it) Store food reserves as glycogen
Besides having the characteristics of living things, animals also: Carry out the following life processes: 1.) Locomotion: motile-can move from one location to another on their own sessile-cannot move from place to place, but do have moving parts Sessile Motile
Life Processes continued 2. Ingestion-take in food 3. Digestion-chemical breakdown of food 4. Assimilation- using the substances obtained from food and utilizing it for growth 5. Reproduction-producing offspring by mitosis or meiosis 6. Respiration-taking in O 2 and breaking down glucose to release energy Ingestion
_____________________ So now that we’ve got all these animals, how do we make sense of it all? TAXONOMY! Taxonomy-Science of classifying organisms and assigning each organism a universally accepted name.
Linnaean Classification System Created by Carl Linnaeus ( ) Before Linnaeus, organisms were classified based on their type of locomotion and physical characteristics Problem? Names were too long, and people describe things differently. Utilizes binomial nomenclature- a two name system (genus and species) Scientific name Ex: Homo sapiens
Scientific Name First name is Genus; second name is species 3 Rules For Scientific Name 1. Italicized or underlined 2. Genus name is Capitalized 3. Species name is lower-case Example: Tursiops truncatus
The Modern Classification System 7 Taxa: Kingdom Phylum Class Order Family Genus Species
Modern Evolutionary Classification Traditional classification used physical appearances or anatomy, because they didn’t have access to modern technology. Biologists now group organisms based on evolutionary descent, not just physical similarities. These are shown with a cladogram, a diagram that shows the evolutionary relationship among a group of organisms.
Cladistic analysis identifies and considers only those characteristics of organisms that are evolutionary innovations—new characteristics that arise as lineages evolve over time. Characteristics that appear in recent parts of a lineage but not in its older members are called derived characters.
Similarities in DNA and RNA The genes of many organisms show important similarities at the molecular level. These similarities can be used as criteria to help determine classification. DNA comparisons are useful on very different organisms such as yeast and primates, to indicate a common ancestry. DNA comparisons on similar organisms helps to establish related species.
Molecular Clocks Comparisons of DNA can also be used to mark the passage of evolutionary time. A model known as a molecular clock uses DNA comparisons to estimate the length of time that two species have been evolving independently. This is done by observing mutations in the DNA Natural selection is a driving force in speciation, the formation of new species.
The Three Domain System The three domains are: Bacteria—Eubacteria Archaea—Archaebacteria Eukarya—Protists, Fungi, Plantae, Animalia