"Systematic biology" redirects here.
For the journal, see Systematic Biology.
For other uses, see Systematics (disambiguation).
Phylogenies have two components: branching order (showing group relationships) and branch length (showing amount of evolution).
Systematics, in other words, is used to understand the evolutionary history of life on Earth.
The word systematics is derived from Latin word `systema', which means systematic arrangement of organisms.
Branches and applications
In the study of biological systematics, researchers use the different branches to further understand the relationships between differing organisms.
These branches are used to determine the applications and uses for modern day systematics.
Biological systematics classifies species by using three specific branches.
Numerical systematics, or biometry, uses biological statistics to identify and classify animals.
Experimental systematics identifies and classifies animals based on the evolutionary units that comprise a species, as well as their importance in evolution itself.
Factors such as mutations, genetic divergence, and hybridization all are considered evolutionary units.
With the specific branches, researchers are able to determine the applications and uses for modern-day systematics.
These applications include:
- Studying the diversity of organisms and the differentiation between extinct and living creatures. Biologists study the well-understood relationships by making many different diagrams and "trees" (cladograms, phylogenetic trees, phylogenies, etc.).
- Including the scientific names of organisms, species descriptions and overviews, taxonomic orders, and classifications of evolutionary and organism histories.
- Explaining the biodiversity of the planet and its organisms. The systematic study is that of conservation.
- Manipulating and controlling the natural world. This includes the practice of 'biological control', the intentional introduction of natural predators and disease.
Definition and relation with taxonomy
John Lindley provided an early definition of systematics in 1830, although he wrote of "systematic botany" rather than using the term "systematics".
In 1970 Michener et al.
defined "systematic biology" and "taxonomy" (terms that are often confused and used interchangeably) in relationship to one another as follows:
Taxonomy, systematic biology, systematics, biosystematics, scientific classification, biological classification, phylogenetics: At various times in history, all these words have had overlapping, related meanings.
However, in modern usage, they can all be considered synonyms of each other.
For example, Webster's 9th New Collegiate Dictionary of 1987 treats "classification", "taxonomy", and "systematics" as synonyms.
According to this work, the terms originated in 1790, c. 1828, and in 1888 respectively.
Some claim systematics alone deals specifically with relationships through time, and that it can be synonymous with phylogenetics, broadly dealing with the inferred hierarchy of organisms.
This means it would be a subset of taxonomy as it is sometimes regarded, but the inverse is claimed by others.
Europeans tend to use the terms "systematics" and "biosystematics" for the study of biodiversity as a whole, whereas North Americans tend to use "taxonomy" more frequently.
However, taxonomy, and in particular alpha taxonomy, is more specifically the identification, description, and naming (i.e. nomenclature) of organisms, while "classification" focuses on placing organisms within hierarchical groups that show their relationships to other organisms.
Systematics uses taxonomy as a primary tool in understanding, as nothing about an organism's relationships with other living things can be understood without it first being properly studied and described in sufficient detail to identify and classify it correctly.
Scientific classifications are aids in recording and reporting information to other scientists and to laymen.
The systematist, a scientist who specializes in systematics, must, therefore, be able to use existing classification systems, or at least know them well enough to skilfully justify not using them.
Phenetics was an attempt to determine the relationships of organisms through a measure of overall similarity, making no distinction between plesiomorphies (shared ancestral traits) and apomorphies (derived traits).
Taxonomic characters are the taxonomic attributes that can be used to provide the evidence from which relationships (the phylogeny) between taxa are inferred.
Kinds of taxonomic characters include:
Credits to the contents of this page go to the authors of the corresponding Wikipedia page: en.wikipedia.org/wiki/Systematics.