Classification and taxonomy of animals refer to the system used to group and categorize animals based on their evolutionary relationships and physical characteristics. The science of taxonomy is concerned with the identification, classification, and naming of living organisms.
The current system of classification and taxonomy of animals is based on the Linnaean system, named after the Swedish naturalist Carolus Linnaeus. In this system, animals are grouped into a hierarchical series of categories, ranging from the most general to the most specific. These categories are:
- Kingdom: The highest level of classification, animals are classified in the Kingdom Animalia, which includes all multicellular organisms that are heterotrophic and lack cell walls.
- Phylum: Animals are further classified into different phyla based on their body plan and organization. For example, Arthropoda is a phylum that includes animals with segmented bodies and jointed appendages, while Chordata is a phylum that includes animals with a dorsal nerve cord and a notochord.
- Class: Within each phylum, animals are further classified into classes based on additional physical characteristics. For example, the class Mammalia includes animals that have hair or fur, mammary glands, and are warm-blooded.
- Order: Within each class, animals are classified into orders based on similarities in physical characteristics and evolutionary history. For example, the order Primates includes animals such as humans, apes, and monkeys.
- Family: Within each order, animals are classified into families based on their evolutionary relationships and shared physical characteristics. For example, the family Hominidae includes humans and their closest evolutionary relatives.
- Genus: Within each family, animals are classified into genera based on their physical and genetic similarities. For example, the genus Homo includes modern humans and our extinct ancestors.
- Species: The most specific level of classification, animals are classified into species based on their ability to interbreed and produce fertile offspring. For example, Homo sapiens is the scientific name for modern humans.
The Linnaean system of classification and taxonomy is a useful tool for organizing and understanding the diversity of animal life, but it is not without its limitations. New advances in genetics and evolutionary biology have led to the development of new approaches to classification, such as cladistics and molecular systematics, which focus on the evolutionary relationships between organisms rather than just their physical characteristics.