What hierarchy of taxa do taxonomists use to classify species?

Sourav PanNovember 8, 2024

Answered

Taxonomists classify species using a hierarchical system known as taxonomic hierarchy, which organizes living organisms into successive levels based on shared characteristics. This system was significantly developed by Carl Linnaeus in the 18th century and is still widely used today.

Hierarchical Levels of Taxonomy

The modern taxonomic hierarchy consists of eight primary ranks, listed from the most inclusive to the most specific:

1. Domain: The highest taxonomic rank, which categorizes life into three major domains:
   • Bacteria: Prokaryotic microorganisms.
   • Archaea: Prokaryotes that often inhabit extreme environments.
   • Eukarya: Organisms with eukaryotic cells, including animals, plants, fungi, and protists.
2. Kingdom: The next level down, which further divides organisms within each domain. For example, in the domain Eukarya, there are five recognized kingdoms: Animalia, Plantae, Fungi, Protista, and Monera.
3. Phylum (or Division in Botany): Groups organisms based on major body plans or structural features. For instance, Chordata is a phylum that includes all animals with a notochord.
4. Class: A more specific category within a phylum. For example, Mammalia is the class that includes all mammals.
5. Order: This rank groups related families together. An example is the order Carnivora, which includes families like Felidae (cats) and Canidae (dogs).
6. Family: A group of related genera (plural of genus). For example, the family Hominidae includes humans and their close relatives.
7. Genus: A group of closely related species that share common characteristics. For instance, Canis is the genus that includes dogs and wolves.
8. Species: The most specific level of classification, representing individuals that can interbreed and produce fertile offspring. For example, Canis lupus refers specifically to the gray wolf.

Summary of Taxonomic Hierarchy