36-522: Allenia Cinclocerthia Dumetella Margarops Melanoptila Melanotis Mimus Oreoscoptes Ramphocinclus Toxostoma The mimids are the New World family of passerine birds, Mimidae , that includes thrashers , mockingbirds , tremblers , and the New World catbirds . As their name ( Latin for "mimic") suggests, these birds are notable for their vocalization, especially some species' remarkable ability to mimic
72-470: A thrush . Adults of the nominate subspecies have a dark gray-brown head and upperparts with a reddish tinge on the rump. Their tail is a darker brownish black and its outer feathers have white tips. The folded wing shows a single white bar. Their chin and throat are whitish with brown streaks. The underparts are whitish and the chest and flanks have bold gray-brown markings that give the eponymous scaly appearance. The other subspecies differ mostly in size and
108-479: A "single common ancestor" organism. Paraphyly is common in speciation , whereby a mother species (a paraspecies ) gives rise to a daughter species without itself becoming extinct. Research indicates as many as 20 percent of all animal species and between 20 and 50 percent of plant species are paraphyletic. Accounting for these facts, some taxonomists argue that paraphyly is a trait of nature that should be acknowledged at higher taxonomic levels. Cladists advocate
144-413: A bush or tree. The clutch size is two or three. [REDACTED] The scaly-breasted thrasher's song is a "[s]eries of varied notes and phrases" similar to that of Mimus mockingbirds but softer and slower. The IUCN has assessed the scaly-breasted thrasher as being of Least Concern. It is fairly common to common through most of its range though rare on Grenada. Paraphyletic Paraphyly
180-592: A cell nucleus, a plesiomorphy ) from its excluded descendants. Also, some systematists recognize paraphyletic groups as being involved in evolutionary transitions, the development of the first tetrapods from their ancestors for example. Any name given to these hypothetical ancestors to distinguish them from tetrapods—"fish", for example—necessarily picks out a paraphyletic group, because the descendant tetrapods are not included. Other systematists consider reification of paraphyletic groups to obscure inferred patterns of evolutionary history. The term " evolutionary grade "
216-419: A group of dinosaurs (part of Diapsida ), both of which are "reptiles". Osteichthyes , bony fish, are paraphyletic when circumscribed to include only Actinopterygii (ray-finned fish) and Sarcopterygii (lungfish, etc.), and to exclude tetrapods ; more recently, Osteichthyes is treated as a clade, including the tetrapods. The " wasps " are paraphyletic, consisting of the narrow-waisted Apocrita without
252-439: A kind of lizard). Put another way, viviparity is a synapomorphy for Theria within mammals, and an autapomorphy for Eulamprus tympanum (or perhaps a synapomorphy, if other Eulamprus species are also viviparous). Groupings based on independently-developed traits such as these examples of viviparity represent examples of polyphyly , not paraphyly. The following list recapitulates a number of paraphyletic groups proposed in
288-549: A more inclusive clade, it often makes sense to study the paraphyletic group that remains without considering the larger clade. For example, the Neogene evolution of the Artiodactyla (even-toed ungulates, like deer, cows, pigs and hippopotamuses - Cervidae , Bovidae , Suidae and Hippopotamidae , the families that contain these various artiodactyls, are all monophyletic groups) has taken place in environments so different from that of
324-424: A phylogenetic species concept that does not consider species to exhibit the properties of monophyly or paraphyly, concepts under that perspective which apply only to groups of species. They consider Zander's extension of the "paraphyletic species" argument to higher taxa to represent a category error When the appearance of significant traits has led a subclade on an evolutionary path very divergent from that of
360-495: A rather thrush -like pattern: brown above, pale with dark streaks or spots below. They tend to have longer tails than thrushes (or the bigger wrens , which they also resemble) and longer bills that in many species curve downward. They have long, strong legs (for passerines) with which many species hop through undergrowth searching for arthropods and fruits to eat. Their habitat varies from forest undergrowth to scrub, high-altitude grasslands, and deserts. The two tremblers live in
396-521: A wide variety of birds and other sounds heard outdoors. They are commonly referred to as mimic thrushes but are not, in fact, thrushes (which are members of family Turdidae ). There are over 30 species of mimids in two larger and some ten small or monotypic genera . They tend toward dull grays and browns in their appearance, though a few are black or blue-gray, and many have red, yellow, or white irises . They range from 20 to 33 centimetres in length, and 36 to 56 grams in weight. Many mimids have
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#1732855909101432-419: Is a taxonomic term describing a grouping that consists of the grouping's last common ancestor and some but not all of its descendant lineages. The grouping is said to be paraphyletic with respect to the excluded subgroups. In contrast, a monophyletic grouping (a clade ) includes a common ancestor and all of its descendants. The terms are commonly used in phylogenetics (a subfield of biology ) and in
468-439: Is a monophyletic group from which one or more subsidiary clades (monophyletic groups) are excluded to form a separate group. Philosopher of science Marc Ereshefsky has argued that paraphyletic taxa are the result of anagenesis in the excluded group or groups. A cladistic approach normally does not grant paraphyletic assemblages the status of "groups", nor does it reify them with explanations, as in cladistics they are not seen as
504-683: Is a species of bird in the family Mimidae . It is found throughout much of the Lesser Antilles of the Caribbean Sea . The scaly-breasted thrasher was originally placed in genus Margarops with the pearly-eyed thrasher ( M. fuscatus ) but is now in the monotypic genus Allenia . It has five subspecies: The scaly-breasted thrasher is approximately 23 cm (9.1 in) long and weighs 53 to 98 g (1.9 to 3.5 oz) with an average weight of 67 g (2.4 oz). With its rather short and slightly decurved bill, this thrasher resembles
540-433: Is allowed as a synonym of Magnoliopsida. Phylogenetic analysis indicates that the monocots are a development from a dicot ancestor. Excluding monocots from the dicots makes the latter a paraphyletic group. Among animals, several familiar groups are not, in fact, clades. The order Artiodactyla ( even-toed ungulates ) as traditionally defined is paraphyletic because it excludes Cetaceans (whales, dolphins, etc.). Under
576-450: Is also found around human settlements. The scaly-breasted thrasher forages in trees; on different islands it hunts at different levels from low down to high in the canopy. It is omnivorous; its diet includes arthropods , fruits, and berries. It appears to eat a larger percentage of vegetable foods than other thrashers. The scaly-breasted thrasher breeds in May and June. It builds a cup nest in
612-442: Is paraphyletic with respect to birds . Reptilia contains the last common ancestor of reptiles and all descendants of that ancestor except for birds. Other commonly recognized paraphyletic groups include fish , monkeys , and lizards . The term paraphyly , or paraphyletic , derives from the two Ancient Greek words παρά ( pará ), meaning "beside, near", and φῦλον ( phûlon ), meaning "genus, species", and refers to
648-482: Is sometimes used for paraphyletic groups. Moreover, the concepts of monophyly , paraphyly, and polyphyly have been used in deducing key genes for barcoding of diverse group of species. Current phylogenetic hypotheses of tetrapod relationships imply that viviparity , the production of offspring without the external laying of a fertilized egg, developed independently in the lineages that led to humans ( Homo sapiens ) and southern water skinks ( Eulampus tympanum ,
684-503: The Cetacea (whales, dolphins, and porpoises) that the Artiodactyla are often studied in isolation even though the cetaceans are a descendant group. The prokaryote group is another example; it is paraphyletic because it is composed of two Domains (Eubacteria and Archaea) and excludes (the eukaryotes ). It is very useful because it has a clearly defined and significant distinction (absence of
720-569: The ICN ) abandoned consideration of bacterial nomenclature in 1975; currently, prokaryotic nomenclature is regulated under the ICNB with a starting date of 1 January 1980 (in contrast to a 1753 start date under the ICBN/ICN). Among plants, dicotyledons (in the traditional sense) are paraphyletic because the group excludes monocotyledons . "Dicotyledon" has not been used as a botanic classification for decades, but
756-689: The Philippine creepers if they are not outright but highly apomorphic starlings) form a group of Muscicapoidea which originated probably in the Early Miocene – very roughly 25–20 mya – somewhere in East Asia . This is evidenced by the Asian-SW Pacific distribution of the most basal starlings (and Philippine creepers) and the North American range of the basal mimids. They are sometimes united with
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#1732855909101792-638: The ants and bees . The sawflies ( Symphyta ) are similarly paraphyletic, forming all of the Hymenoptera except for the Apocrita, a clade deep within the sawfly tree. Crustaceans are not a clade because the Hexapoda (insects) are excluded. The modern clade that spans all of them is the Tetraconata . One of the goals of modern taxonomy over the past fifty years has been to eliminate paraphyletic "groups", such as
828-524: The basal branching pattern is not well resolved. The tremblers, again, are a monophyletic lineage. The latter, however, are embedded in a paraphyletic catbird- Caribbean thrasher assemblage which consists of many rather basal lineages. For detailed information on the evolutionary relationships of the different mimid lineages, see their articles. Mockingbirds : New World catbirds : Thrashers : Tremblers Allenia Margarops fuscus The scaly-breasted thrasher ( Allenia fusca )
864-448: The tree model of historical linguistics . Paraphyletic groups are identified by a combination of synapomorphies and symplesiomorphies . If many subgroups are missing from the named group, it is said to be polyparaphyletic. The term received currency during the debates of the 1960s and 1970s accompanying the rise of cladistics , having been coined by zoologist Willi Hennig to apply to well-known taxa like Reptilia ( reptiles ), which
900-495: The actual products of evolutionary events. A group whose identifying features evolved convergently in two or more lineages is polyphyletic (Greek πολύς [ polys ], "many"). More broadly, any taxon that is not paraphyletic or monophyletic can be called polyphyletic. Empirically, the distinction between polyphyletic groups and paraphyletic groups is rather arbitrary, since the character states of common ancestors are inferences, not observations. These terms were developed during
936-406: The atypical habitat of rainforests in the Lesser Antilles , and the brown trembler has the particularly atypical behavior of foraging while clinging to tree trunks. All known species build somewhat messy, bulky twig nests in dense growth, which are in most species on the ground or no more than 2 meters up. They usually lay 2 to 5 eggs that hatch in 12 or 13 days, which is also the length of time
972-621: The chicks stay in the nest. Breeding usually starts in the spring or early in the rainy season, and many species can have two or even three broods per year. Most failures to fledge young are due to predation. Pairs often stay together for more than one breeding season. Contrary to often-held belief, the Nesomimus mockingbirds may have played at least as great a role as Darwin's finches in inspiring Darwin's work on his theory of evolution. Phylogenetic analyses have shown that mimids are most closely related to starlings . These and oxpeckers (and
1008-490: The debates of the 1960s and 1970s accompanying the rise of cladistics . Paraphyletic groupings are considered problematic by many taxonomists, as it is not possible to talk precisely about their phylogenetic relationships, their characteristic traits and literal extinction. Related terms are stem group , chronospecies , budding cladogenesis, anagenesis, or 'grade' groupings. Paraphyletic groups are often relics from outdated hypotheses of phylogenic relationships from before
1044-471: The descendants of a unique common ancestor. By comparison, the term polyphyly , or polyphyletic , uses the Ancient Greek prefix πολύς ( polús ), meaning "many, a lot of", and refers to the fact that a polyphyletic group includes organisms arising from multiple ancestral sources. Groups that include all the descendants of a common ancestor are said to be monophyletic . A paraphyletic group
1080-450: The examples given here, from formal classifications. Species have a special status in systematics as being an observable feature of nature itself and as the basic unit of classification. Some articulations of the phylogenetic species concept require species to be monophyletic, but paraphyletic species are common in nature, to the extent that they do not have a single common ancestor. Indeed, for sexually reproducing taxa, no species has
1116-491: The intensity of their upperparts' color. A. f. hypenema is the largest and is paler than the nominate. A. f. schwartzi is mid-sized and has more white on its tail. A. f. vincenti is the smallest and is darker overall than the nominate. A. f. atlantica compared to the nominate is more reddish brown above and has less white in the tail. The subspecies of scaly-breasted thrasher are found thus: The scaly-breasted thrasher primarily inhabits forest and semi-open woodland and
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1152-605: The literature, and provides the corresponding monophyletic taxa. The concept of paraphyly has also been applied to historical linguistics , where the methods of cladistics have found some utility in comparing languages. For instance, the Formosan languages form a paraphyletic group of the Austronesian languages because they consist of the nine branches of the Austronesian family that are not Malayo-Polynesian and are restricted to
1188-675: The ranks of the ICZN Code , the two taxa are separate orders. Molecular studies, however, have shown that the Cetacea descend from artiodactyl ancestors, although the precise phylogeny within the order remains uncertain. Without the Cetaceans the Artiodactyls are paraphyletic. The class Reptilia is paraphyletic because it excludes birds (class Aves ). Under a traditional classification, these two taxa are separate classes. However birds are sister taxon to
1224-563: The rise of cladistics. The prokaryotes (single-celled life forms without cell nuclei) are a paraphyletic grouping, because they exclude the eukaryotes , a descendant group. Bacteria and Archaea are prokaryotes, but archaea and eukaryotes share a common ancestor that is not ancestral to the bacteria. The prokaryote/eukaryote distinction was proposed by Edouard Chatton in 1937 and was generally accepted after being adopted by Roger Stanier and C.B. van Niel in 1962. The botanical code (the ICBN, now
1260-405: The situation in which one or several monophyletic subgroups of organisms (e.g., genera, species) are left apart from all other descendants of a unique common ancestor. Conversely, the term monophyly , or monophyletic , builds on the Ancient Greek prefix μόνος ( mónos ), meaning "alone, only, unique", and refers to the fact that a monophyletic group includes organisms consisting of all
1296-459: The starlings in the Sturnidae as a tribe Mimini as proposed by Sibley & Monroe (1990). This makes the expanded Sturnidae a rather noninformative group and is probably due to the methodological drawbacks of their DNA-DNA hybridization technique. The mockingbirds with some thrashers seem to form one major clade , while the two other groups and the remaining thrashers seem to form another, but
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