Variety (biology)

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The variety ( Latin varietas , abbreviated var.) Is a taxonomic rank in biology that is now only used in botany and mycology . The variety is a secondary rank between subspecies and form and is used for populations that differ only slightly from the type . In the past, the terms variety or variety were also used .

botany

According to today's view, a variety comprises several populations that deviate from the type form in individual or very few characteristics , but in contrast to the subspecies do not have their own area . The only difference between the two varieties of real chervil ( Anthriscus cerefolium ) is the hairiness of the fruit and the nuances of taste.

Often is a variety no natural kinship group, but includes a group of striking indeed, but taxonomically little relevant features . Very often they neither have their own area nor do they have a specific location link. The biological meaning of the characteristics and thus the variety is therefore often unclear.

zoology

According to Articles 45.6.3 and 4 ICZN , varieties that were published as such before 1961 are now to be classified as subspecies. Descriptions after 1960 as being below the subspecies are outside the scope of the code according to Article 15.2. In zoology and human biology today, the terms are genetic variation and modification use.

history

The Latin word varietas was used long before Linnaeus in the systematics with the meaning “diversity, variation, change”. This denotes small deviations from the ideal type of the species. In general, the early taxonomists found it difficult to use variation , as their concept of species was an essentialist one and not shaped by population thinking .

Carl von Linné was the first to formalize the concept of variety. With him and other early taxonomists, the variety was the only rank below the species. In general, Linné varieties were unimportant, they considered them to be reversible modifications.

However, Linné's variety comprised a very heterogeneous group of deviations from the type characteristics. He summarized at least four different phenomena here: non-genetic modifications due to differences in diet, climate, etc .; Breeds of domestic animals and crops ; genetically fixed variation within a population, as well as geographic races. So it was hereditary as well as non-hereditary traits, differences between individuals and between populations. In his Philosophia Botanica (1751), for example, in the section on plants, he attributed the variety to the influence of the climate or the soil, which would disappear again in another climate or soil. In the section on animals, he also presented the hereditary characteristics of the breeds as varieties. Variety names were often identified by Greek letters and appended to the species name. For a long time the variety was the most important rank below the species.

As already indicated by Linnaeus, the importance of the variety in zoology and botany was separated early on. Zoologists long used variety for geographic races, while botanists used it to refer to cultivated varieties or variants within a population.

Around the middle of the 19th century, the conceptual separation of subspecies for geographical races and varieties for variants within a population began to establish itself in zoology. As a result, the term variety largely disappeared from taxonomy in zoology and is only used in some areas for individual variants. In botany, too, the subspecies replaced the variety as the most important rank below the species, but retained the meaning described above. In North America, however, the variety has largely retained the same meaning as the subspecies in botany.

literature

  • Ernst Mayr : The Growth of Biological Thought. Diversity, Evolution and Inheritance. 12th Printing, The Belknap Press of Harvard University Press, Cambridge 2003, ISBN 0-674-36446-5 , pp. 288f, 640f. (History).

See also

Individual evidence

  1. ↑ Article 4 , ICBN , accessed January 17 , 2009.
  2. ^ A b c Manfred A. Fischer , Karl Oswald, Wolfgang Adler: Excursion flora for Austria, Liechtenstein and South Tyrol. 3rd, improved edition. State of Upper Austria, Biology Center of the Upper Austrian State Museums, Linz 2008, ISBN 978-3-85474-187-9 , p. 40f.
  3. ↑ a b c d Gerhard Wagenitz : Dictionary of Botany. The terms in their historical context. 2nd, expanded edition. Spektrum Akademischer Verlag, Heidelberg / Berlin 2003, ISBN 3-8274-1398-2 , pp. 341f.
  4. ↑ Article 45 ICZN. Retrieved January 17, 2009.
  5. ↑ Article 15.2 ICZN. Retrieved January 17, 2009.