Emerald Robinson: Hi, I'm Emerald Robinson, and in this What Is? video, we're going to discuss Taxonomy.
Taxonomy is a system that biologists use to group organisms based on similar characteristics. Taxonomy is based on a concept called homology, shared characteristics that have been passed down, from a common ancestor.
Although humans have been classifying organisms by various methods since ancient times, Swedish biologist Carolus Linnaeus is considered to be the father of modern taxonomy. His most famous work, Systema Naturae, established a system we still used today to determine an organism's scientific name. This system is called binomial nomenclature.
To understand what makes that the binomial nomenclature, we need to start at the top. Classic biological taxonomy usually places an organism into one of five kingdoms: bacteria, protists, plants, fungi, or animals. Each organism is then classified into the following groups: phylum, class, order, family, genus, and species. It is the genus and species that makes up an organism's scientific name. For example, the scientific name for humans is Homo sapiens, where Homo is the genus, and sapiens the species.
Sometimes scientists classify organisms using a three domain system. The three currently accepted domains are Archaea, single-celled microorganisms that tend to live in extreme environments like very high heat or salt concentration; Bacteria, which are abundant and live in most habitats on Earth, and Eukaryotes, any organism made of cells which contain a membrane-bound nucleus.
Although we use to classify organisms based on characteristics that could be seen by the naked eye or under a microscope, today we commonly rely on analyzing an organism's DNA instead.
Scientists will continue to use these means to classify the approximately 15,000 new species that are identified each year.