A cladogram (from Greek clados "branch" and gramma "character") is a diagram used in cladistics to show relations among organisms. A cladogram is not, however, an evolutionary tree because it does not show how ancestors are related to descendants, nor does it show how much they have changed, so many differing evolutionary trees can be consistent with the same cladogram. A cladogram uses lines that branch off in different directions ending at a clade , a group of organisms with a last common ancestor . There are many shapes of cladograms but they all have lines that branch off from other lines. The lines can be traced back to where they branch off. These branching off points represent a hypothetical ancestor (not an actual entity) which can be inferred to exhibit the traits shared among the terminal taxa above it. This hypothetical ancestor might then provide clues about the order of evolution of various features, adaptation, and other evolutionary narratives about ancestors. Although traditionally such cladograms were generated largely on the basis of morphological characters, DNA and RNA sequencing data and computational phylogenetics are now very commonly used in the generation of cladograms, either on their own or in combination with morphology.
72-455: Alternate taxonomy: The Bovidae comprise the biological family of cloven-hoofed , ruminant mammals that includes cattle , bison , buffalo , antelopes (including goat-antelopes ), sheep and goats . A member of this family is called a bovid . With 143 extant species and 300 known extinct species , the family Bovidae consists of 11 (or two) major subfamilies and thirteen major tribes. The family evolved 20 million years ago, in
144-446: A t e s {\displaystyle n.states} , c i occupies a range from 1 to ( n . s t a t e s − 1 ) / ( n . t a x a − ⌈ n . t a x a / n . s t a t e s ⌉ ) {\displaystyle (n.states-1)/(n.taxa-\lceil n.taxa/n.states\rceil )} . The retention index (RI)
216-445: A metric to measure how consistent a candidate cladogram is with the data. Most cladogram algorithms use the mathematical techniques of optimization and minimization. In general, cladogram generation algorithms must be implemented as computer programs, although some algorithms can be performed manually when the data sets are modest (for example, just a few species and a couple of characteristics). Some algorithms are useful only when
288-540: A character in a phylogenetic analysis as they do not contribute anything to our understanding of relationships. However, homoplasy is often not evident from inspection of the character itself (as in DNA sequence, for example), and is then detected by its incongruence (unparsimonious distribution) on a most-parsimonious cladogram. Note that characters that are homoplastic may still contain phylogenetic signal . A well-known example of homoplasy due to convergent evolution would be
360-412: A cladogram can be roughly categorized as either morphological (synapsid skull, warm blooded, notochord , unicellular, etc.) or molecular (DNA, RNA, or other genetic information). Prior to the advent of DNA sequencing, cladistic analysis primarily used morphological data. Behavioral data (for animals) may also be used. As DNA sequencing has become cheaper and easier, molecular systematics has become
432-422: A dataset, the degree to which each character carries phylogenetic information, and the fashion in which additive characters are coded, rendering it unfit for purpose. c i occupies a range from 1 to 1/[ n.taxa /2] in binary characters with an even state distribution; its minimum value is larger when states are not evenly spread. In general, for a binary or non-binary character with n . s t
504-412: A different shape. The horns of female bovids are believed to have evolved for defence against predators or to express territoriality, as nonterritorial females, which are able to use crypsis for predator defence, often do not have horns. Females possess horns only in half of the bovid genera, and females in these genera are heavier than those in the rest. Females use horns mainly for stabbing. In bovids,
576-667: A few such as the buffalo, bushbuck, reedbuck, and grysbok are exceptions. Social activity and feeding usually peak during dawn and dusk. The bovids usually rest before dawn, during midday, and after dark. Grooming is usually by licking with the tongue. Rarely do antelopes roll in mud or dust. Wildebeest and buffalo usually wallow in mud, whereas the hartebeest and topi rub their heads and horns in mud and then smear it over their bodies. Bovids use different forms of vocal, olfactory, and tangible communication. These involve varied postures of neck, head, horns, hair, legs, and ears to convey sexual excitement, emotional state, or alarm. One such expression
648-554: A lack of widespread consensus within the scientific community for extended periods. The continual publication of new data and diverse opinions plays a crucial role in facilitating adjustments and ultimately reaching a consensus over time. The naming of families is codified by various international bodies using the following suffixes: The taxonomic term familia was first used by French botanist Pierre Magnol in his Prodromus historiae generalis plantarum, in quo familiae plantarum per tabulas disponuntur (1689) where he called
720-457: A larger clade. The incongruence length difference test (ILD) is a measurement of how the combination of different datasets (e.g. morphological and molecular, plastid and nuclear genes) contributes to a longer tree. It is measured by first calculating the total tree length of each partition and summing them. Then replicates are made by making randomly assembled partitions consisting of the original partitions. The lengths are summed. A p value of 0.01
792-507: A level muzzle. Fighting techniques differ amongst the bovid families and also depend on their build. While the hartebeest fight on knees, others usually fight on all fours. Gazelles of various sizes use different methods of combat. Gazelles usually box, and in serious fights may clash and fence, consisting of hard blows from short range. Ibex, goat and sheep males stand upright and clash into each other downwards. Wildebeest use powerful head butting in aggressive clashes. If horns become entangled,
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#1732765676909864-452: A more and more popular way to infer phylogenetic hypotheses. Using a parsimony criterion is only one of several methods to infer a phylogeny from molecular data. Approaches such as maximum likelihood , which incorporate explicit models of sequence evolution, are non-Hennigian ways to evaluate sequence data. Another powerful method of reconstructing phylogenies is the use of genomic retrotransposon markers , which are thought to be less prone to
936-467: A pale white (as in the Arabian oryx ) to black (as in the black wildebeest ). However, only the intermediate shades, such as brown and reddish brown (as in the reedbuck ), are commonly observed. In several species, females and juveniles exhibit a light-coloured coat, while those of males darken with age. As in the wildebeest , the coat may be marked with prominent or faint stripes. In some species such as
1008-487: A permanent sheath of keratin . Most bovids bear 30 to 32 teeth. Most bovids are diurnal . Social activity and feeding usually peak during dawn and dusk. Bovids typically rest before dawn, during midday, and after dark. They have various methods of social organisation and social behaviour , which are classified into solitary and gregarious behaviour. Bovids use different forms of vocal, olfactory, and tangible communication. Most species alternately feed and ruminate throughout
1080-820: A permanent sheath of keratin. Although horns occur in a single pair on almost all bovid species, there are exceptions such as the four-horned antelope and the Jacob sheep . The unique horn structure is the only unambiguous morphological feature of bovids that distinguishes them from other pecorans . A high correlation exists between horn morphology and fighting behaviour of the individual. For instance, long horns are intended for wrestling and fencing, whereas curved horns are used in ramming. Males with horns directed inwards are monogamous and solitary, while those with horns directed outwards tend to be polygynous . These results were independent of body size. Male horn development has been linked to sexual selection , Horns are small spikes in
1152-513: A tribe of Caprinae, in Africa date back to the late Miocene. The earliest Hippotragine fossils date back to the late Miocene, and were excavated from sites such as Lothagam and Awash Valley . The first African fossils of Reduncinae date back to 6-7 Mya. Reduncinae and Peleinae probably diverged in the mid-Miocene. All bovids have the similar basic form - a snout with a blunt end, one or more pairs of horns (generally present on males) immediately after
1224-410: Is a character state that is shared by two or more taxa due to some cause other than common ancestry. The two main types of homoplasy are convergence (evolution of the "same" character in at least two distinct lineages) and reversion (the return to an ancestral character state). Characters that are obviously homoplastic, such as white fur in different lineages of Arctic mammals, should not be included as
1296-590: Is believed to have come into being in the Pliocene, but became extinct in the middle Pleistocene . Several genera of Hippotraginae are known since the Pliocene and Pleistocene. This subfamily appears to have diverged from the Alcelaphinae in the latter part of early Miocene. The Bovinae are believed to have diverged from the rest of the Bovidae in the early Miocene . The Boselaphini became extinct in Africa in
1368-499: Is commonly referred to as the "walnut family". The delineation of what constitutes a family— or whether a described family should be acknowledged— is established and decided upon by active taxonomists . There are not strict regulations for outlining or acknowledging a family, yet in the realm of plants, these classifications often rely on both the vegetative and reproductive characteristics of plant species. Taxonomists frequently hold varying perspectives on these descriptions, leading to
1440-707: Is disputed, with suggestions of as many as ten and as few as two subfamilies. However, molecular, morphological and fossil evidence indicates the existence of eight distinct subfamilies: Aepycerotinae (consisting of just the impala), Alcelaphinae (bontebok, hartebeest, wildebeest and relatives), Antilopinae (several antelopes, gazelles, and relatives), Bovinae (cattle, buffaloes, bison and other antelopes), Caprinae (goats, sheep, ibex, serows and relatives), Cephalophinae (duikers), Hippotraginae (addax, oryx and relatives) and Reduncinae (reedbuck and kob antelopes). In addition, three extinct subfamilies are known: Hypsodontinae (mid- Miocene ), Oiocerinae ( Turolian ) and
1512-491: Is in the savannas of Eastern Africa . Other bovid species also occur in Europe, Asia, and North America. Bovidae includes a number of domesticated species, including three whose use has spread worldwide, namely cattle , sheep , and goats . Dairy products , such as milk , butter , and cheese , are manufactured largely from domestic cattle. Bovids are also raised for their leather , meat , and wool . The name "Bovidae"
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#17327656769091584-411: Is obtained for 100 replicates if 99 replicates have longer combined tree lengths. Some measures attempt to measure the amount of homoplasy in a dataset with reference to a tree, though it is not necessarily clear precisely what property these measures aim to quantify The consistency index (CI) measures the consistency of a tree to a set of data – a measure of the minimum amount of homoplasy implied by
1656-485: Is one of the eight major hierarchical taxonomic ranks in Linnaean taxonomy . It is classified between order and genus . A family may be divided into subfamilies , which are intermediate ranks between the ranks of family and genus. The official family names are Latin in origin; however, popular names are often used: for example, walnut trees and hickory trees belong to the family Juglandaceae , but that family
1728-400: Is the flehmen response . Bovids usually stand motionless, with the head high and an intent stare, when they sense danger. Some like the impala, kudu, and eland can even leap to heights of a few feet. Bovids may roar or grunt to caution others and warn off predators. Bovids such as gazelles stot or pronk in response to predators, making high leaps on stiff legs, indicating honestly both that
1800-717: Is the only bovid that is both solitary and not territorial. This antelope hardly displays aggression, and tends to isolate itself or form loose herds, though in a favourable habitat, several bushbuck may be found quite close to one another. Excluding the cephalophines (duikers), tragelaphines (spiral-horned antelopes) and the neotragines, most African bovids are gregarious and territorial. Males are forced to disperse on attaining sexual maturity, and must form their own territories, while females are not required to do so. Males that do not hold territories form bachelor herds. Competition takes place among males to acquire dominance, and fights tend to be more rigorous in limited rutting seasons . With
1872-526: Is usually done by comparison to the character states of one or more outgroups . States shared between the outgroup and some members of the in-group are symplesiomorphies; states that are present only in a subset of the in-group are synapomorphies. Note that character states unique to a single terminal (autapomorphies) do not provide evidence of grouping. The choice of an outgroup is a crucial step in cladistic analysis because different outgroups can produce trees with profoundly different topologies. A homoplasy
1944-461: The Genera Plantarum of George Bentham and Joseph Dalton Hooker this word ordo was used for what now is given the rank of family. Families serve as valuable units for evolutionary, paleontological, and genetic studies due to their relatively greater stability compared to lower taxonomic levels like genera and species. Cladogram The characteristics used to create
2016-1120: The Antilopinae , was later placed in its own subfamily, Pantholopinae . However, molecular and morphological analysis supports the inclusion of Pantholops in Caprinae . Below is a cladogram based on Yang et al . , 2013 and Calamari, 2021: Bovini (bison, buffalo, cattle, etc.) [REDACTED] Boselaphini (nilgai and four-horned antelope) [REDACTED] Tragelaphini (kudus, nyalas etc.) [REDACTED] Aepycerotinae (impala) [REDACTED] Nesotraginae (suni and bates's antelope) Antilopinae (gazelles, springbok, dik-dik, royal antelope, saiga, etc.) [REDACTED] Cephalophinae (duikers etc.) [REDACTED] Oreotraginae (klipspringer) Reduncinae (kobs, reedbucks, waterbucks etc.) [REDACTED] Caprinae (chamois, sheep, ibexes, goats, muskox, etc.) [REDACTED] Alcelaphinae (hartebeest, topi, wildebeest etc.) [REDACTED] Hippotraginae (sable antelopes, oryxes etc.) [REDACTED] Alternatively, all members of
2088-487: The addax , the coat colour can vary by the season. Scent glands and sebaceous glands are often present. Some species, such as the gemsbok , sable antelope , and Grant's gazelle , are camouflaged with strongly disruptive facial markings that conceal the highly recognisable eye. Many species, such as gazelles, may be made to look flat, and hence to blend into the background, by countershading . The outlines of many bovids are broken up with bold disruptive colouration,
2160-1044: The dental pad , that provides a surface to grip grasses and foliage. They are hypsodont and selenodont , since the molars and premolars are low- crowned and crescent-shaped cusps . The lower incisors and canines project forward. The incisors are followed by a long toothless gap, known as the diastema . The general dental formula for bovids is 0.0.2-3.3 3.1.3.3 . Most members of the family are herbivorous , but most duikers are omnivorous . Like other ruminants, bovids have four-chambered stomachs, which allow them to digest plant material, such as grass , that cannot be used by many other animals. Ruminants (and some others like kangaroos , rabbits , and termites ) are able to use micro-organisms living in their guts to break down cellulose by fermentation . The bovids have various methods of social organisation and social behaviour, which are classified into solitary and gregarious behaviour. Further, these types may each be divided into territorial and nonterritorial behaviour. Small bovids such as
2232-527: The Aegodontia, can be classified within the subfamily Antilopinae, with the individual subfamilies being tribes in this treatment. In the early Miocene, bovids began diverging from the cervids (deer) and giraffids . The earliest bovids, whose presence in Africa and Eurasia in the latter part of early Miocene (20 Mya ) has been ascertained, were small animals, somewhat similar to modern gazelles , and probably lived in woodland environments. Eotragus ,
Bovidae - Misplaced Pages Continue
2304-439: The Bovidae, where for example Bos , Ovis , bontebok and gemsbok have white stockings. Again, communication is the likely function. Excepting some domesticated forms, all male bovids have horns, and in many species, females, too, possess horns. The size and shape of the horns vary greatly, but the basic structure is a pair of simple bony protrusions without branches, often having a spiral, twisted, or fluted form, each covered in
2376-556: The Bovidae-Moschidae clade 27 to 28 million years ago. The following cladogram is based on the 2003 study. Tragulidae [REDACTED] Antilocapridae [REDACTED] Giraffidae [REDACTED] Cervidae [REDACTED] Moschidae [REDACTED] Bovidae [REDACTED] Molecular studies have supported monophyly in the family Bovidae (a group of organisms comprises an ancestral species and all their descendants). The number of subfamilies in Bovidae
2448-406: The Pliocene. By the late Miocene, around 10 Mya, the bovids rapidly diversified , leading to the creation of 70 new genera. This late Miocene radiation was partly because many bovids became adapted to more open, grassland habitats. The Aepycerotinae first appeared in the late Miocene, and no significant difference in the sizes of the primitive and modern impala has been noted. Fossils of ovibovines,
2520-437: The afternoon. Temperature is regulated through sweating in cattle, whereas goats use panting for the same. The right lung , consisting of four to five lobes , is around 1.5 times larger than the left, which has three lobes. Most bovids bear 30 to 32 teeth. While the upper incisors are absent, the upper canines are either reduced or absent. Instead of the upper incisors, bovids have a thick and tough layer of tissue, called
2592-417: The beginning of the 21st century it was understood that the family Moschidae (musk deer) was sister to Cervidae . However, a 2003 phylogenetic study by Alexandre Hassanin (of National Museum of Natural History, France ) and colleagues, based on mitochondrial and nuclear analyses, revealed that Moschidae and Bovidae form a clade sister to Cervidae . According to the study, Cervidae diverged from
2664-431: The character, "presence of wings". Although the wings of birds, bats , and insects serve the same function, each evolved independently, as can be seen by their anatomy . If a bird, bat, and a winged insect were scored for the character, "presence of wings", a homoplasy would be introduced into the dataset, and this could potentially confound the analysis, possibly resulting in a false hypothesis of relationships. Of course,
2736-434: The characteristic data are molecular (DNA, RNA); other algorithms are useful only when the characteristic data are morphological. Other algorithms can be used when the characteristic data includes both molecular and morphological data. Algorithms for cladograms or other types of phylogenetic trees include least squares , neighbor-joining , parsimony , maximum likelihood , and Bayesian inference . Biologists sometimes use
2808-409: The complex cellulose into simpler fatty acids , which are then absorbed through the rumen wall. Bovids have a long small intestine ; the length of the small intestine in cattle is 29–49 m (95–161 ft). Body temperature fluctuates through the day; for instance, in goats the temperature can change slightly from nearly 37 °C (99 °F) in the early morning to 40 °C (104 °F) in
2880-691: The dataset). The rescaled consistency index (RC) is obtained by multiplying the CI by the RI; in effect this stretches the range of the CI such that its minimum theoretically attainable value is rescaled to 0, with its maximum remaining at 1. The homoplasy index (HI) is simply 1 − CI. This measures the amount of homoplasy observed on a tree relative to the maximum amount of homoplasy that could theoretically be present – 1 − (observed homoplasy excess) / (maximum homoplasy excess). A value of 1 indicates no homoplasy; 0 represents as much homoplasy as there would be in
2952-596: The day. While small bovids forage in dense and closed habitat, larger species feed on high-fiber vegetation in open grasslands. Most bovids are polygynous . Mature bovids mate at least once a year and smaller species may even mate twice. In some species, neonate bovids remain hidden for a week to two months, regularly nursed by their mothers; in other species, neonates are followers, accompanying their dams, rather than tending to remain hidden. The greatest diversities of bovids occur in Africa . The maximum concentration of species
Bovidae - Misplaced Pages Continue
3024-504: The duiker browse for a few hours during day or night. Feeding habits are related to body size; while small bovids forage in dense and closed habitat, larger species feed upon high-fiber vegetation in open grasslands. Subfamilies exhibit different feeding strategies. While Bovinae species graze extensively on fresh grass and diffused forage, Cephalophinae species (with the exception of Sylvicapra ) primarily consume fruits. Reduncinae and Hippotraginae species depend on unstable food sources, but
3096-496: The earliest known bovid, weighed 18 kg (40 lb) and was nearly the same in size as the Thomson's gazelle . Early in their evolutionary history, the bovids split into two main clades: Boodontia (of Eurasian origin) and Aegodontia (of African origin). This early split between Boodontia and Aegodontia has been attributed to the continental divide between these land masses. When these continents were later rejoined, this barrier
3168-419: The early Miocene . The bovids show great variation in size and pelage colouration. Except some domesticated forms , all male bovids have two or more horns , and in many species, females possess horns, too. The size and shape of the horns vary greatly, but the basic structure is always one or more pairs of simple bony protrusions without branches, often having a spiral, twisted or fluted form, each covered in
3240-517: The early Pliocene; their latest fossils were excavated in Langebaanweg (South Africa) and Lothagam (Kenya). The middle Miocene marked the spread of the bovids into China and the Indian subcontinent. According to Vrba, the radiation of the subfamily Alcelaphinae began in the latter part of middle Miocene. The Caprinae tribes probably diverged in the early middle Miocene. The Caprini emerged in
3312-719: The exception of migratory males, males generally hold the same territory throughout their lives. In the waterbuck, some male individuals, known as "satellite males", may be allowed into the territories of other males and have to wait till the owner grows old so they may acquire his territory. Lek mating , where males gather together and competitively display to potential mates, is known to exist among topis , kobs , and lechwes . The tragelaphines, cattle, sheep, and goats are gregarious and not territorial. In these species, males must gain absolute dominance over all other males, and fights are not confined to territories. Males, therefore, spend years in body growth. Most bovids are diurnal, although
3384-540: The family as a rank intermediate between order and genus was introduced by Pierre André Latreille in his Précis des caractères génériques des insectes, disposés dans un ordre naturel (1796). He used families (some of them were not named) in some but not in all his orders of "insects" (which then included all arthropods ). In nineteenth-century works such as the Prodromus of Augustin Pyramus de Candolle and
3456-497: The ground. The bovids show great variation in size: the gaur can weigh more than 1,500 kg (3,300 lb), and stand 2.2 m (87 in) high at the shoulder. The royal antelope , in sharp contrast, is only 25 cm (9.8 in) tall and weighs at most 3 kg (6.6 lb). The klipspringer , another small antelope, stands 45–60 cm (18–24 in) at the shoulder and weighs just 10–20 kg (22–44 lb). Differences occur in pelage colouration, ranging from
3528-480: The klipspringer, oribi , and steenbok are generally solitary and territorial. They hold small territories into which other members of the species are not allowed to enter. These antelopes form monogamous pairs. Many species such as the dik-dik use pheromone secretions from the preorbital glands and sometimes dung, as well, to mark their territories. The offspring disperse at the time of adolescence, and males must acquire territories prior to mating. The bushbuck
3600-516: The latter are specially adapted to arid areas. Members of Caprinae, being flexible feeders, forage even in areas with low productivity. Tribes Alcelaphini, Hippotragini, and Reduncini have high proportions of monocots in their diets. On the contrary, Tragelaphini and Neotragini (with the exception of Ourebia ) feed extensively on dicots . No conspicuous relationship exists between body size and consumption of monocots. Family (biology) Family ( Latin : familia , pl. : familiae )
3672-498: The middle Miocene, and seem to have been replaced by other bovids and cervids in Eurasia. The earliest fossils of the antilopines are from the middle Miocene, though studies show the existence of the subfamily from the early Miocene. Speciation occurred in the tribe Antilopini during the middle or upper Miocene, mainly in Eurasia. Tribe Neotragini seems to have appeared in Africa by the end of Miocene, and had become widespread by
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#17327656769093744-428: The monogamous duikers and other small antelopes, whereas in the polygynous, they are large and elaborately formed (for example in a spiral structure, as in the giant eland ). Thus, to some extent, horns depict the degree of competition among males in a species. However, the presence of horns in females is likely due to natural selection . The horns of females are usually smaller than those of males, and are sometimes of
3816-705: The only reason a homoplasy is recognizable in the first place is because there are other characters that imply a pattern of relationships that reveal its homoplastic distribution. A cladogram is the diagrammatic result of an analysis, which groups taxa on the basis of synapomorphies alone. There are many other phylogenetic algorithms that treat data somewhat differently, and result in phylogenetic trees that look like cladograms but are not cladograms. For example, phenetic algorithms, such as UPGMA and Neighbor-Joining, group by overall similarity, and treat both synapomorphies and symplesiomorphies as evidence of grouping, The resulting diagrams are phenograms, not cladograms, Similarly,
3888-410: The opponent's head rather than its body. The S-shaped horns, such as those on the impala , have various sections that help in ramming, holding, and stabbing. Serious fights leading to injury are rare. Most bovids alternately feed and ruminate throughout the day. While those that feed on concentrate feed and digest in short intervals, the roughage feeders take longer intervals. Only small species such as
3960-429: The opponents move in a circular manner to unlock them. Muskoxen will ram into each other at high speeds. As a rule, only two bovids of equal build and level of defence engage in a fight, which is intended to determine the superior of the two. Individuals that are evidently inferior to others would rather flee than fight; for example, immature males do not fight with the mature bulls. Generally, bovids direct their attacks on
4032-441: The oval or pointed ears, a distinct neck and limbs, and a tail varying in length and bushiness among the species. Most bovids exhibit sexual dimorphism , with males usually larger as well as heavier than females. Sexual dimorphism is more prominent in medium- to large-sized bovids. All bovids have four toes on each foot – they walk on the central two (the hooves ), while the outer two (the dewclaws ) are much smaller and rarely touch
4104-497: The predator has been seen, and that the stotting individual is strong and not worth chasing. In the mating season, rutting males bellow to make their presence known to females. Muskoxen roar during male-male fights, and male saigas force air through their noses, producing a roar to deter rival males and attract females. Mothers also use vocal communication to locate their calves if they get separated. During fights over dominance, males tend to display themselves in an erect posture with
4176-499: The problem of reversion that plagues sequence data. They are also generally assumed to have a low incidence of homoplasies because it was once thought that their integration into the genome was entirely random; this seems at least sometimes not to be the case, however. Researchers must decide which character states are "ancestral" ( plesiomorphies ) and which are derived ( synapomorphies ), because only synapomorphic character states provide evidence of grouping. This determination
4248-436: The program settles on a local minimum rather than the desired global minimum. To help solve this problem, many cladogram algorithms use a simulated annealing approach to increase the likelihood that the selected cladogram is the optimal one. The basal position is the direction of the base (or root) of a rooted phylogenetic tree or cladogram. A basal clade is the earliest clade (of a given taxonomic rank[a]) to branch within
4320-481: The recognition of Peleinae and Pantholopinae , comprising the genera Pelea and Pantholops respectively, as subfamilies . In 2000, American biologist George Schaller and palaeontologist Elisabeth Vrba suggested the inclusion of Pelea in Reduncinae , though the grey rhebok, the sole species of Pelea , is highly different from kobs and reduncines in morphology. Pantholops , earlier classified in
4392-405: The results of model-based methods (Maximum Likelihood or Bayesian approaches) that take into account both branching order and "branch length," count both synapomorphies and autapomorphies as evidence for or against grouping, The diagrams resulting from those sorts of analysis are not cladograms, either. There are several algorithms available to identify the "best" cladogram. Most algorithms use
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#17327656769094464-575: The seventy-six groups of plants he recognised in his tables families ( familiae ). The concept of rank at that time was not yet settled, and in the preface to the Prodromus Magnol spoke of uniting his families into larger genera , which is far from how the term is used today. In his work Philosophia Botanica published in 1751, Carl Linnaeus employed the term familia to categorize significant plant groups such as trees , herbs , ferns , palms , and so on. Notably, he restricted
4536-469: The strongly contrasting patterns helping to delay recognition by predators. However, all the Hippotraginae (including the gemsbok) have pale bodies and faces with conspicuous markings. The zoologist Tim Caro describes this as difficult to explain, but given that the species are diurnal, he suggests that the markings may function in communication. Strongly contrasting leg colouration is common only in
4608-726: The subfamily Tethytraginae , which contains Tethytragus (mid- Miocene ). In 1992, Alan W . Gentry of the Natural History Museum, London divided the eight major subfamilies of Bovidae into two major clades on the basis of their evolutionary history: the Boodontia, which comprised only the Bovinae, and the Aegodontia, which consisted of the rest of the subfamilies. Boodonts have somewhat primitive teeth, resembling those of oxen , whereas aegodonts have more advanced teeth like those of goats. A controversy exists about
4680-460: The term parsimony for a specific kind of cladogram generation algorithm and sometimes as an umbrella term for all phylogenetic algorithms. Algorithms that perform optimization tasks (such as building cladograms) can be sensitive to the order in which the input data (the list of species and their characteristics) is presented. Inputting the data in various orders can cause the same algorithm to produce different "best" cladograms. In these situations,
4752-405: The third and fourth metapodials are combined into the cannon bone . The ulna and fibula are reduced, and fused with the radius and tibia, respectively. Long scapulae are present, whereas the clavicles are absent. Being ruminants , the stomach is composed of four chambers: the rumen (80%), the omasum , the reticulum , and the abomasum . The ciliates and bacteria of the rumen ferment
4824-406: The tree. It is calculated by counting the minimum number of changes in a dataset and dividing it by the actual number of changes needed for the cladogram. A consistency index can also be calculated for an individual character i , denoted c i . Besides reflecting the amount of homoplasy, the metric also reflects the number of taxa in the dataset, (to a lesser extent) the number of characters in
4896-549: The use of this term solely within the book's morphological section, where he delved into discussions regarding the vegetative and generative aspects of plants. Subsequently, in French botanical publications, from Michel Adanson 's Familles naturelles des plantes (1763) and until the end of the 19th century, the word famille was used as a French equivalent of the Latin ordo (or ordo naturalis ). In zoology ,
4968-423: The user should input the data in various orders and compare the results. Using different algorithms on a single data set can sometimes yield different "best" cladograms, because each algorithm may have a unique definition of what is "best". Because of the astronomical number of possible cladograms, algorithms cannot guarantee that the solution is the overall best solution. A nonoptimal cladogram will be selected if
5040-495: Was given by the British zoologist John Edward Gray in 1821. The word "Bovidae" is the combination of the prefix bov- (originating from Latin bos , "ox", through Late Latin bovinus ) and the suffix -idae . The family Bovidae is placed in the order Artiodactyla (which includes the even-toed ungulates ). It includes 143 extant species, accounting for nearly 55% of the ungulates , and 300 known extinct species. Until
5112-399: Was proposed as an improvement of the CI "for certain applications" This metric also purports to measure of the amount of homoplasy, but also measures how well synapomorphies explain the tree. It is calculated taking the (maximum number of changes on a tree minus the number of changes on the tree), and dividing by the (maximum number of changes on the tree minus the minimum number of changes in
5184-622: Was removed, and both groups expanded into the territory of the other. The tribes Bovini and Tragelaphini diverged in the early Miocene. Bovids are known to have reached the Americas in the Pleistocene by crossing the Bering land bridge . The present genera of Alcelaphinae appeared in the Pliocene . The extinct Alcelaphine genus Paramularius , which was the same in size as the hartebeest,
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