An Introduction to Animal Classification
Animals are multicellular, living organisms in the Kingdom Animalia. With few exceptions, all animals eat organic matter, breathe oxygen, can move, can breed sexually, and secrete body salts and acids into the environment. The three domains of animal life are: animals, which include reptiles and amphibians; Protista, which include fishes, mammals, birds, and even some forms of insects; and Eutheria, which include all other creatures that are classified as plants or animals. Animalia include all the animals and plants that have lived through a number ofozoans, protozoa, eukarya, and metazoans, but not all animals that lived before the earth had existed.
Plants and animals share many characteristics, but not all can be classified in the animal kingdom. Animals are divided into two broad classifications: asexually reproducing (asexual) animals and asexually un reproducing (sexually reproducing) animals. The sexual reproduction system of an animal is generally classified into two types: autogenesis and sexual reproduction. Autogenesis is the process by which an animal grows and creates new offspring; sexual reproduction is the process by which an animal leaves its parents and travels to a mate for reproduction. Animals reproduce through different processes. Some reproduce by mating and producing children; others reproduce through eating their mates or through the placenta of an adult animal.
The classifications of animals can also be based on how animals are classified according to their size. Animals fall into two main categories, including those that are large in size and those that are small in size. The largest animal is the biggest organism, and the smallest animal is the smallest organism.
Insects are a major part of life, drawing food from the plants they pollinate. Many animals have insectivores, including bees, flies, wasps, and ants. Bees produce honey and wax, and some species of ants are members of the Order Orthoptera. Many scientists believe that these insects are the most important component of the ecosystem because they consume a significant portion of the Earth’s food supply. Other animals such as birds, fish, amphibians, mammals, and reptiles all have some sort of insectivore.
The classification of animals can also be based on the arrangement of their skeletons and their modes of reproduction. The skeletal arrangements of animals are categorized into three primary Phyla. These are chords, brachiopods, and metathesis. Brachiopods and metatheria are not considered to be true phytoplanktons, which are groups of molluscs and other live cephalopods.
In addition to the classification of animals based on their skeletal structures, there are also other methods used to classify animals, including the use of radiocarbon dating, archeology, DNA analysis, and genetic analysis. Each of these methods has been useful in determining the relationship and the relationships of various animals and insects. Sometimes, though, DNA analysis is not enough to prove or identify an animal. Because animals include insects and molluscs, their comparative study is very important, as well.