Comparing Taxonomy: The search for a common ancestor.Featured science projectScience project video

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There are millions of species of plants and animals, and the ability to study them requires a system for classifying them. Taxonomy is the study of how living things are related to each other. By classifying a species, it is possible to find how closely it is related to other species based on its link to a common ancestor. In this science project, you will visit a zoo, botanical garden, or other facility, find species that interest you and compare their taxonomy.


Compare the taxonomy of different species.


Taxonomy describes the system for classifying living organisms. All living species that have been classified by scientist are classified using the follow categories:

  • Kingdom
  • Phylum
  • Class
  • Order
  • Family
  • Genius
  • Species

Example: The taxonomy of a black bear (Ursus americanus) is:

Kingdom: Animalia

Phylum: Chordata

Class: Mammalia

Order: Carnivora

Family: Ursidae

Genus: Ursus

Species: americanus

Example: The taxonomy of a sea lion (Scientific name: Zalophus californianus)


Kingdom: Animalia

Phylum: Chordata

Class: Mammalia

Order: Carnivora

Family: Otariidae

Genus: Zalophus

Species: californianus

When we compare the taxonomy of a black bear and sea lion, we find that they share a lot in common. They share the same classifications for kingdom, phylum, and order. Their classifications differ at the level of family and genus. The lowest classification they share in common is order. This tells us that both the sea lion and the black bear have a common ancestor at this level.

Scientific Terms

Taxonomy, Kingdom, Phylum, Class, Order, Family, Genius, Species


  1. Internet access
  2. Access to one or more of the following:
    1. Zoo
    2. Oceanarium
    3. Specialized pet stores for fish, birds, or reptiles.
    4. Nursery
    5. Botanical garden
  3. Camera
  4. Journal and writing instrument
  5. Scratch paper
  6. Posterboard


  1. Visit one or more of the recommended animal or plant facilities (Note: Choose animal or plant species, not both.
  2. Select three different species that interest you.
  3. While viewing the species, take a photograph or make a drawing of the species. Note both the common and scientific name for each of the species.
  4. Using the internet, research the kingdom, phylum, class, order, family, genius, for each of the species.
  5. Compare the taxonomy of your species as described in the background section.
  6. At what level or levels do you see commonality?
  7. Use the poster board to create a display for your science fair project. Include the following:
    1. An introduction to what taxonomy means.
    2. The objective of the science project.
    3. Photographs of your species.
    4. The common and scientific names of the species.
    5. An explanation of the level or levels that the species in common.
    6. A conclusion of what you learned from the project.


When comparing the taxonomy of different species, it may seem difficult to see how different species have a common ancestor. When comparing a bear to a sea lion, the only similarities that may seem evident is that they are both mammals. Sometimes species share common taxonomy based on anatomical similarities. The skull of both sea lions and bears are very similar. What does this tell you about evolution of these two animals when one is an aquatic creature and the other is terrestrial, or land living.

Questions & Answers

What is the taxonomy of a human?

Kingdom: Animalia

Phylum: Chordata

Class: Mammalia

Order: Primates

Family: Hominidae

Genus: Homo

Species: sapien

Make it Your Own

Create a phylogenetic tree (see bibliography for resources).