KINGDOM

Kingdom: Definition, History, and Characteristics

Abstract
This paper provides an overview of the scientific concept of kingdom. It defines kingdom and its evolution from the Linnaean taxonomy system to the modern cladistic system. Additionally, the characteristics of kingdoms are discussed, including their hierarchical structure and species diversity. Finally, the paper provides a list of references for further reading.

Introduction
The term “kingdom” is used to refer to the highest level of taxonomic classification, and is part of the traditional Linnaean taxonomy system of biological classification. It is the second most inclusive taxon, with domain being the most inclusive. The Linnaean taxonomy system is based on the hierarchical arrangement of living organisms into increasingly specific groupings. The kingdom is the most general taxonomic classification used to arrange organisms, and its application has changed over time.

History
The concept of kingdom was developed by Swedish naturalist Carolus Linnaeus. Linnaeus, who is often referred to as the “father of taxonomy,” developed a system of classification in the 18th century which became known as the Linnaean taxonomy system. This system was based on the hierarchical arrangement of living organisms into increasingly specific groupings. The kingdom was the most general taxonomic classification and was used to arrange organisms into five distinct groups, which were: animals, plants, fungi, protists, and monera. This system was later expanded to include seven kingdoms, with the addition of archaebacteria and eubacteria.

Over time, the Linnaean system of classification was replaced by the modern cladistic system, which is based on the evolutionary relationships between organisms. The seven kingdom classification system is still used in some circles, but has been largely replaced by the three domain system. This system is based on the differences in the molecular structure of the genetic material of organisms and is divided into three domains: bacteria, archaea, and eukarya.

Characteristics
Kingdoms are hierarchical classifications of organisms based on their shared characteristics. Kingdoms are typically divided into phyla, classes, orders, families, genera, and species. The hierarchical nature of kingdoms allows for easy identification of organisms, as well as their evolutionary relationships.

Kingdoms are also characterized by their species diversity. Kingdoms contain a wide range of species, and the diversity within each kingdom is vast. For example, the Animal kingdom contains species from all five major animal phyla (porifera, platyhelminthes, aschelminthes, annelida, and mollusca).

Conclusion
In conclusion, kingdoms are the highest level of taxonomic classification used to arrange organisms. The concept of kingdom was developed by Swedish naturalist Carolus Linnaeus and has evolved over time from the Linnaean taxonomy system to the modern cladistic system. Kingdoms are characterized by their hierarchical structure and species diversity.

References
Benton, M. J. (2019). Vertebrate Palaeontology (5th ed.). Oxford University Press.

Dawson, M. (2008). A Field Guide to Fossils (4th ed.). Houghton Mifflin Harcourt.

Garrity, G. M., & Lilburn, T. G. (Eds.). (2018). Bergey’s Manual of Systematics of Archaea and Bacteria (5th ed.). John Wiley & Sons, Inc.

Gill, F. B. (Ed.). (2006). Ornithology (3rd ed.). W.H. Freeman and Company.

McCarthy, P. M., & McLeod, K. L. (Eds.). (2006). Plant Systematics (2nd ed.). Academic Press.

Sneath, P. H. A., & Sokal, R. R. (1973). Numerical Taxonomy. W.H. Freeman and Company.