How Are the Scientific Kingdoms Divided?

All living things on this planet are classed in one of five possible kingdoms: animal, plant, fungi, protist and moneran. These kingdoms are then further separated into six different basic classification phases that group living things with other related lifeforms. These classifications help science to trace the common origins of all living things.

  1. Phyla

    • Each kingdom of lifeforms is separated into phyla. Each living thing is designated into a particular phylum according to common ancestors and some basic anatomical similarities. An example of a creature associated with a phylum might be a polar bear. It belongs to the phylum chordata because it has a structure called a notocord within its body during early development.

    Class

    • The next main grouping phase is known as scientific classes. These groupings further separate living things into groups with several common traits such as mammals, reptiles, fish and birds. For example the polar bear, which belongs to the mammalian class, is in this group because it possesses fur, three inner ear bones and produces milk for its young. Sometimes certain classes are related closely enough in evolutionary terms to be grouped together as a superclass -- for example, the tetrapod class, which includes birds, reptiles and amphibians.

    Order

    • After being separated into classes, kingdoms are further broken down into orders. This is a grouping based on even more common traits. For example, the polar bear belongs to the order carnivora, which includes mammals that tend to be meat eaters or at least eat both vegetation and meat. The dentition of the animals in this order tend to designed for eating flesh.

    Family

    • The next step down in classification is families that group living things based on even closer relationships. These families can be large or possess just a few members. The family ursidae, to which polar bears belong, is a small family with only eight members. They are all bears and look noticeably similar, sharing the same skull shape and dental make up.

    Genus

    • Genera is the next separating step and places living things together with others that are related closely in genetic terms. Members of a genus are always very similar but are just different enough to be not the same. The genus ursus, for example, groups the polar bear with the American black, Asiatic black and brown bears. These four types are all closely related and look alike but show differences mainly in size and color.

    Species

    • The last separation of a kingdom is into individual species. This groups lifeforms that are almost entirely the same save for a few genetic variations. For example, polar bears are all physically the same species. Although they may vary in size and sometimes appearance, they share the same basic genetic structure.