1. Introduction to Zoology
Classification of Animals

2. Review
Biology is the study of life…
So what makes something living?

3. All living things must:
Be made up of at least 1 cell that contains genetic material (DNA)
Grow (increase in size, mature, develop, etc.)
Metabolize (have a need and use for energy)
Respond to stimuli

4. 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?

5. 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

6. 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
Motile
Sessile

7. Life Processes continued
Ingestion
Life Processes continued
Ingestion-take in food
Digestion-chemical breakdown of food
Assimilation- using the substances obtained from food and utilizing it for growth
Reproduction-producing offspring by mitosis or meiosis
Respiration-taking in O2 and breaking down glucose to release energy

8. _____________________
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.

9. 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

10. Scientific Name First name is Genus; second name is species
3 Rules For Scientific Name
Italicized or underlined
Genus name is Capitalized
Species name is lower-case
Example: Tursiops truncatus

11. The Modern Classification System
7 Taxa:
Kingdom
Phylum
Class
Order
Family
Genus
Species

12. 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.

13. Cladogram

14. Cladogram
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.

15. 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.

16. 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.

17. The Three Domain System
The three domains are:
Bacteria—Eubacteria
Archaea—Archaebacteria
Eukarya—Protists, Fungi, Plantae, Animalia