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18-462: Meum is a monotypic genus in the family Apiaceae . Its only species is Meum athamanticum , a glabrous , highly aromatic ( aroma compound ), perennial plant . Common names in the UK include baldmoney, meu or meum, and spignel (also spikenel and spiknel). It is a plant of grassland , often on limestone, in mountain districts of Western Europe and Central Europe , its range extending as far south as

36-602: A common ancestor ) or paraphyletic (excluding some descendants), these concepts do not apply to monotypic taxa because they contain only a single member. Monotypic taxa are part of a broader challenge in biological classification known as aphyly – situations where evolutionary relationships are poorly supported by evidence. This includes both monotypic groups and cases where traditional groupings are found to be artificial. Understanding how monotypic taxa fit into this bigger picture helps identify areas needing further research. The German lichenologist Robert Lücking suggests that

54-407: A condiment and in the preparation of a wide variety of home remedies as a diuretic , to control menstruation and uterine complaints and to treat catarrh , hysteria and stomach ailments. The scent of the roots of Meum has much in common with those of two other edible/medicinal umbellifers : Levisticum officinale and Angelica archangelica , while the aromatic flavour of Meum leaves

72-441: A distinct definition to maintain logical structure. Otherwise, the different taxonomic ranks become effectively identical, which creates problems for organizing biological diversity in a hierarchical system. When taxonomists identify a monotypic taxon, this often reflects uncertainty about its relationships rather than true evolutionary isolation . This uncertainty is evident in many cases across different species. For instance,

90-475: A family. Some examples of monotypic groups are: Synapomorphies In phylogenetics , an apomorphy (or derived trait ) is a novel character or character state that has evolved from its ancestral form (or plesiomorphy ). A synapomorphy is an apomorphy shared by two or more taxa and is therefore hypothesized to have evolved in their most recent common ancestor . In cladistics , synapomorphy implies homology . Examples of apomorphy are

108-477: A synapomorphy is the marker for the most recent common ancestor of the monophyletic group consisting of a set of taxa in a cladogram. What counts as a synapomorphy for one clade may well be a primitive character or plesiomorphy at a less inclusive or nested clade. For example, the presence of mammary glands is a synapomorphy for mammals in relation to tetrapods but is a symplesiomorphy for mammals in relation to one another—rodents and primates, for example. So

126-424: A variety of Bavarian schnapps which is flavoured with its extract. Monotypic taxon Monotypic taxa present several important theoretical challenges in biological classification . One key issue is known as "Gregg's Paradox": if a single species is the only member of multiple hierarchical levels (for example, being the only species in its genus, which is the only genus in its family), then each level needs

144-407: Is particularly associated with island species. Among 25 documented extinct monotypic genera studied, 22 occurred on islands, with flightless animals being particularly vulnerable to human impacts. Just as the term monotypic is used to describe a taxon including only one subdivision, the contained taxon can also be referred to as monotypic within the higher-level taxon, e.g. a genus monotypic within

162-426: Is somewhat like Melilot (which owes its aroma of new-mown hay to coumarin ) and is communicated to milk and butter when cows feed on the foliage in spring. The curious name Baldmoney is said to be derived from the name of the god Baldr ( Scandinavian mythology ) – to whom the plant was dedicated. In German it is known as Bärwurz [bear wort], feminine gender ( die ) for the plant and masculine gender ( der ) for

180-550: The Ancient Greek words σύν ( sún ), meaning "with, together"; ἀπό ( apó ), meaning "away from"; and μορφή ( morphḗ ), meaning "shape, form". Lampreys and sharks share some features, like a nervous system, that are not synapomorphic because they are also shared by invertebrates . In contrast, the presence of jaws and paired appendages in both sharks and dogs, but not in lampreys or close invertebrate relatives, identifies these traits as synapomorphies. This supports

198-635: The Sierra Nevada (Spain) of Andalucia , and central Bulgaria in the Balkans . It is not a very common plant in the UK, being found in only a few localities in N. England and N. Wales although a little more plentiful in Scotland – where it is found as far north as Sutherland . Meum has been cultivated in Scotland, where the roots were eaten as a root vegetable . The delicate, feathery foliage has been used as

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216-745: The common application of the term monotypic is frequently misleading, "since each taxon by definition contains exactly one type and is hence "monotypic", regardless of the total number of units", and suggests using "monospecific" for a genus with a single species, and "monotaxonomic" for a taxon containing only one unit. Species in monotypic genera tend to be more threatened with extinction than average species. Studies have found this pattern particularly pronounced in amphibians , where about 6.56% of monotypic genera are critically endangered , compared to birds and mammals where around 4.54% and 4.02% of monotypic genera face critical endangerment respectively. Studies have found that extinction of monotypic genera

234-531: The concept can be understood as well in terms of "a character newer than" ( autapomorphy ) and "a character older than" ( plesiomorphy ) the apomorphy: mammary glands are evolutionarily newer than vertebral column, so mammary glands are an autapomorphy if vertebral column is an apomorphy, but if mammary glands are the apomorphy being considered then vertebral column is a plesiomorphy. These phylogenetic terms are used to describe different patterns of ancestral and derived character or trait states as stated in

252-400: The diatom Licmophora juergensii is placed in a monotypic genus because scientists have not yet found clear evidence of its relationships to other species. Some taxonomists argue against monotypic taxa because they reduce the information content of biological classifications. As taxonomists Backlund and Bremer explain in their critique, "'Monotypic' taxa do not provide any information about

270-510: The hypothesis that dogs and sharks are more closely related to each other than to lampreys. The concept of synapomorphy depends on a given clade in the tree of life. Cladograms are diagrams that depict evolutionary relationships within groups of taxa. These illustrations are accurate predictive device in modern genetics. They are usually depicted in either tree or ladder form. Synapomorphies then create evidence for historical relationships and their associated hierarchical structure. Evolutionarily,

288-492: The presence of erect gait , fur , the evolution of three middle ear bones , and mammary glands in mammals but not in other vertebrate animals such as amphibians or reptiles , which have retained their ancestral traits of a sprawling gait and lack of fur. Thus, these derived traits are also synapomorphies of mammals in general as they are not shared by other vertebrate animals. The word synapomorphy —coined by German entomologist Willi Hennig —is derived from

306-405: The relationships of the immediately subordinate taxon". When monotypic taxa are sister to a single larger group, they might be merged into that group; however, when they are sister to multiple other groups, they may need to remain separate to maintain a natural classification. From a cladistic perspective, which focuses on shared derived characteristics to determine evolutionary relationships,

324-403: The theoretical status of monotypic taxa is complex. Some argue they can only be justified when relationships cannot be resolved through synapomorphies (shared derived characteristics); otherwise, they would necessarily exclude related species and thus be paraphyletic. However, others contend that while most taxonomic groups can be classified as either monophyletic (containing all descendants of

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