Background

Submitted by rodolfo on Sat, 2010-06-19 12:34

The marine world is mysterious. We know more about the surface of the moon than what is found in our oceans here on Earth. It is estimated that only about 20% of the ocean floor has been mapped out and explored. Marine Scientists are continually finding new species of marine invertebrates; these findings are forcing scientists to reevaluate how animals are classified.

Taxonomy is a branch of biology concerned with naming and classifying the diverse forms of life. The earliest accounts of classifying traces back to Aristotle who classified living things into plants and animals. With the increase of exploration to new lands and communications between different parts of the world scientists began to realize the classification system they had been using was ineffective. A new system had to be created if scientists were to keep abreast of all the new discoveries.

Carolus Linnaeus, the Father of Taxonomy, was a botanist and naturalist from Sweden. In the 1700s Linnaeus founded the system of classifying known as taxonomy. Linnaeus grouped organisms into large groups and broke them down several times into smaller and smaller groups based on shared characteristics. Linnaeus is also accredited with devising a two-part naming system of all living organisms, this system is known as Binomial Nomenclature, and is made up of an organism’s genus and species. While Linnaeus based his classification on organism’s shared characteristics, scientists today base their placement of organisms on a number of factors besides characteristics, such as evolutionary relationships, and DNA analysis. These differences account for the many changes that have been made to Linnaeus’s original system. Although changes have been made the original framework is still in existence and has aided scientists with their work for many years.

Scientists use classification as a tool to aid them when researching organisms. Classification can be used to show how organisms are related, and used as a tool to describe evolutionary changes. The use of Binomial Nomenclature is especially important because when scientists are discussing a certain organism there is never confusion as to what organism is being discussed. The reason for this is the scientific name of an organism is always in Latin; therefore scientists from other countries, who may have different names for the same organism, can communicate effectively. There are seven taxonomic groups that make up the classification system. The largest group is called a Kingdom, and the smallest group is a species. A pictorial of the classification system is described below:

Students will be learning about taxonomy using marine animals. There are several phylums and classes that should be included in this lesson (see list below). All organisms will belong to the Kingdom Animalia. Please note that descriptions for each group can be found in any Biology or Marine Science Textbook. Also please look for the list of “helpful websites” to aid you if you are unfamiliar with a group.

Groups that should be included in Through the Activity:
Phylum-Porifera
Phylum-Cnidarian
Phylum-Echinodermata
Phylum-Molluska Class-Bi-Valve
Phylum-Molluska Class-Cephalopod
Phylum-Arthropod Class-Crustacean
Phylum-Chordata Class-Chondrichthyes
Phylum-Chordata Class-Osteichthyes
Phylum-Chordata Class-Reptilia (sea turtles)
Phylum-Chordata Class-Mammalia (*whales, seals, dolphin)
*You may wish to assign each marine mammal to different groups to show the differences found in the same class. Students usually find the differences easier to see in groups they are already familiar with.

OBIS is a project of:
IOC-UNESCO
IODE Sponsored by:
Martin International and Les Grands Explorateurs
With in-kind support from:
Marine Geospatial Ecology Lab, Duke University
Universidad Simón Bolívar Flanders Marine Institute

OBIS strives to document the ocean's diversity, distribution and abundance of life. Created by the Census of Marine Life, OBIS is now part of the Intergovernmental Oceanographic Commission (IOC) of UNESCO, under its International Oceanographic Data and Information Exchange (IODE) programme.