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85-463: Micranthes stellaris , synonym Saxifraga stellaris , the starry saxifrage or hairy kidney-wort , is an Arctic–alpine species in the family Saxifragaceae . It produces panicles of 5–10 white flowers on a stem up to 20 cm (7.9 in) tall, rising from a basal leaf rosette. One subspecies is found from eastern Canada to Russia, including the British Isles, while another is found in

170-493: A nomen oblitum , and the junior name declared a nomen protectum . This rule exists primarily to prevent the confusion that would result if a well-known name, with a large accompanying body of literature, were to be replaced by a completely unfamiliar name. An example is the European land snail Petasina edentula ( Draparnaud , 1805). In 2002, researchers found that an older name Helix depilata Draparnaud, 1801 referred to

255-434: A chromosome number of 2 n = 28. Micranthes stellaris was first described by Carl Linnaeus in his 1753 work Species Plantarum as Saxifraga stellaris . Linnaeus noted the species' occurrence in the mountains of Spitsbergen , Lapland , Switzerland , Styria and Westmorland . The nominate subspecies , Micranthes stellaris subsp. stellaris is the northern subspecies, occurring from Canada to Russia, including

340-485: A flower or between flowers on an inflorescence . Within-flower interference, which occurs when either the pistil interrupts pollen removal or the anthers prevent pollen deposition, can result in autonomous or facilitated self-pollination. Between-flower interference results from similar mechanisms, except that the interfering structures occur on different flowers within the same inflorescence and it requires pollinator activity. This results in geitonogamous pollination,

425-410: A biological event concerns the molecular and physiological mechanisms that produce the event. Many studies have focused on the proximate causes of sequential hermaphroditism, which may be caused by various hormonal and enzyme changes in organisms. The role of aromatase has been widely studied in this area. Aromatase is an enzyme that controls the androgen / estrogen ratio in animals by catalyzing

510-424: A biological event determines how the event makes organisms better adapted to their environment, and thus why evolution by natural selection has produced that event. While a large number of ultimate causes of hermaphroditism have been proposed, the two causes most relevant to sequential hermaphroditism are the size-advantage model and protection against inbreeding. The size-advantage model states that individuals of

595-442: A brilliant terminal-phase coloration, which has a change in intensity of color, stripes, and bars. Terminal-phase coloration occurs when males become large enough to defend territory. Initial-phase males have larger testes than larger, terminal phase males, which enables the initial-phase males to produce a large amount of sperm. This strategy allows these males to compete with the larger territorial male. Botryllus schlosseri ,

680-424: A certain age or size. In animals, the different types of change are male to female ( protandry or protandrous hermaphroditism ), female to male ( protogyny or protogynous hermaphroditism ), and bidirectional ( serial or bidirectional hermaphroditism ). Both protogynous and protandrous hermaphroditism allow the organism to switch between functional male and functional female. Bidirectional hermaphrodites have

765-453: A certain size. In most ectotherms , body size and female fecundity are positively correlated. This supports the size-advantage model. Kazancioglu and Alonzo (2010) performed the first comparative analysis of sex change in Labridae . Their analysis supports the size-advantage model and suggest that sequential hermaphroditism is correlated to the size-advantage. They determined that dioecy

850-410: A colonial tunicate , is a protogynous hermaphrodite. In a colony, eggs are released about two days before the peak of sperm emission. Although self-fertilization is avoided and cross-fertilization favored by this strategy, self-fertilization is still possible. Self-fertilized eggs develop with a substantially higher frequency of anomalies during cleavage than cross-fertilized eggs (23% vs. 1.6%). Also

935-491: A given sex reproduce more effectively if they are a certain size or age. To create selection for sequential hermaphroditism, small individuals must have higher reproductive fitness as one sex and larger individuals must have higher reproductive fitness as the opposite sex. For example, eggs are larger than sperm, thus larger individuals are able to make more eggs, so individuals could maximize their reproductive potential by beginning life as male and then turning female upon achieving

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1020-410: A harem"). In a paired mating system (one male mates with one female, such as in clownfish or moray eels) the male can only fertilize one batch of eggs, whereas the female needs only a small male to fertilize her batch of eggs. so the larger she is, the more eggs she'll be able to produce and have fertilized. Therefore, in this kind of paired mating system, protandry is the most adaptive strategy ("breed as

1105-413: A haremic mating system, with one large male controlling access to numerous females for mating, this large male achieves greater reprodcutive success than a small female as he can fertilize numerous baches of eggs. So in this kind of haremic mating system (such as many wrasses), protogyny is the most adaptive strategy ("breed as a female when small, and then change to male when you're large and able to control

1190-437: A junior subjective synonym. Objective synonyms are common at the rank of genera, because for various reasons two genera may contain the same type species; these are objective synonyms. In many cases researchers established new generic names because they thought this was necessary or did not know that others had previously established another genus for the same group of species. An example is the genus Pomatia Beck, 1837, which

1275-428: A listing of "synonyms", a "synonymy", often contains designations that for some reason did not make it as a formal name, such as manuscript names, or even misidentifications (although it is now the usual practice to list misidentifications separately ). Although the basic principles are fairly similar, the treatment of synonyms in botanical nomenclature differs in detail and terminology from zoological nomenclature, where

1360-513: A loose panicle comprising 5–10 flowers; each flower has deflexed sepals , surrounding five white petals , 3–6 millimetres (0.12–0.24 in) long, with two yellow or red spots near the base. The anthers are also red or yellow. Flowers are borne from June to August. The seeds are dark brown, glabrous, 0.6–0.8 mm (0.024–0.031 in) long, and 0.3–0.4 mm (0.012–0.016 in) wide. They are elliptic, ovoid or reniform in shape, with longitudinal ribs bearing spines. M. stellaris has

1445-458: A male when small, and then change to female when you're larger"). Sequential hermaphroditism can also protect against inbreeding in populations of organisms that have low enough motility and/or are sparsely distributed enough that there is a considerable risk of siblings encountering each other after reaching sexual maturity, and interbreeding. If siblings are all the same or similar ages, and if they all begin life as one sex and then transition to

1530-558: A more general mechanism for reducing pollen-pistil interference. Hermaphroditic fishes are almost exclusively sequential—simultaneous hermaphroditism is only known to occur in one species of fish, the Rivulid killifish Kryptolebias marmoratus . Additionally, Teleost fishes are the only vertebrate lineage where sequential hermaphroditism occurs. In general, protandrous hermaphrodites are animals that develop as males, but can later reproduce as females. However, protandry features

1615-414: A more general mechanism for reducing the impact of pollen - pistil interference on pollen import and export. Unlike the inbreeding avoidance hypothesis, which focused on female function, this interference-avoidance hypothesis considers both reproductive functions. In many hermaphroditic plant species, the close physical proximity of anthers and stigma makes interference unavoidable, either within

1700-410: A nonsexual juvenile plant, to a young all-male plant, to a male-and-female plant, to an all-female plant. This means that A. triphyllum is changing its sex from male to female over the course of its lifetime as its size increases, showcasing Size Dependent Sex Allocation. Another example is Arisaema dracontium or the green dragon, which can change its sex on a yearly basis. The sex of A. dracontium

1785-753: A period of several years, and are sequential hermaphrodites. When branches were removed from striped maple trees they changed to female or to female and male as a response to the damage. Sickness will also trigger a sex change to either female or female and male. In the context of the sexuality of flowering plants (angiosperms), there are two forms of dichogamy: protogyny —female function precedes male function—and protandry —male function precedes female function. Examples include in Asteraceae , bisexual tubular (disks) florets are usually protandrous. Whereas in Acacia and Banksia flowers are protogynous, with

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1870-405: A severe reproductive disadvantage, which promotes strong selection of size-based protogyny. Therefore, if an individual is small, it is more reproductively advantageous to be female because they will still be able to reproduce, unlike small males. Common model organisms for this type of sequential hermaphroditism are wrasses . They are one of the largest families of coral reef fish and belong to

1955-507: A sex ratio biased towards the birth sex, and consequently experience significantly more reproductive success after switching sexes. According to the population genetics theory, this should decrease genetic diversity and effective population size (Ne). However, a study of two ecologically similar santer sea bream ( gonochoric ) and slinger sea bream (protogynous) in South African waters found that genetic diversities were similar in

2040-455: A significantly lower percentage of larvae derived from self-fertilized eggs metamorphose, and the growth of the colonies derived from their metamorphosis is significantly lower. These findings suggest that self-fertilization gives rise to inbreeding depression associated with developmental deficits that are likely caused by expression of deleterious recessive mutations. Other examples of protogynous organisms include: The ultimate cause of

2125-440: A species is moved to a different genus, a variety is moved to a different species, etc. Synonyms also come about when the codes of nomenclature change, so that older names are no longer acceptable; for example, Erica herbacea L. has been rejected in favour of Erica carnea L. and is thus its synonym. To the general user of scientific names, in fields such as agriculture, horticulture, ecology, general science, etc.,

2210-434: A species, or simple ignorance about an earlier description, may lead a biologist to describe a newly discovered specimen as a new species. A common reason for objective synonyms at this level is the creation of a replacement name. A junior synonym can be given precedence over a senior synonym, primarily when the senior name has not been used since 1899, and the junior name is in common use. The older name may be declared to be

2295-507: A spectrum of different forms, which are characterized by the overlap between male and female reproductive function throughout an organism's lifetime: Furthermore, there are also species that reproduce as both sexes throughout their lifespans (i.e simultaneous hermaphrodites ), but shift their reproductive resources from male to female over time. Protandry occurs in a widespread range of animal phyla. In fact, protandrous hermaphroditism occurs in many fish, mollusks , and crustaceans , but

2380-418: A synonym is a name that was previously used as the correct scientific name (in handbooks and similar sources) but which has been displaced by another scientific name, which is now regarded as correct. Thus Oxford Dictionaries Online defines the term as "a taxonomic name which has the same application as another, especially one which has been superseded and is no longer valid". In handbooks and general texts, it

2465-418: A synonym is not interchangeable with the name of which it is a synonym. In taxonomy, synonyms are not equals, but have a different status. For any taxon with a particular circumscription , position, and rank, only one scientific name is considered to be the correct one at any given time (this correct name is to be determined by applying the relevant code of nomenclature ). A synonym cannot exist in isolation: it

2550-481: A taxon, some of this (including species descriptions, distribution, ecology and more) may well have been published under names now regarded as outdated (i.e., synonyms) and so it is again useful to know a list of historic synonyms which may have been used for a given current (valid) taxon name. Objective synonyms refer to taxa with the same type and same rank (more or less the same taxon, although circumscription may vary, even widely). This may be species-group taxa of

2635-404: Is a more common form of sequential hermaphroditism in fish, especially when compared to protandry. As the animal ages, it shifts sex to become a male animal due to internal or external triggers, undergoing physiological and behavioral changes. In many fishes, female fecundity increases continuously with age, while in other species larger males have a selective advantage (such as in harems), so it

Micranthes stellaris - Misplaced Pages Continue

2720-737: Is abundant in North Wales , Northern England and Scotland , reaching the summit of Ben Nevis (1,344 m or 4,409 ft), but is only found locally in Ireland . Its southernmost stations in Great Britain are the slopes of Plynlimon and the Rheidol valley ; it does not occur in the mountains of South Wales . In the Vosges , it occurs around 3,600 ft (1,100 m), but only rarely below 4,300–4,600 ft (1,300–1,400 m) in

2805-467: Is also dependent on size: the smaller flowers are male while the larger flowers are both male and female. Typically in Arisaema species, small flowers only contain stamens, meaning they are males. Larger flowers can contain both stamen and pistils or only pistils, meaning they can be either hermaphrodites or strictly female. Striped maple trees ( Acer pensylvanicum ) have been shown to change sex over

2890-493: Is always an alternative to a different scientific name. Given that the correct name of a taxon depends on the taxonomic viewpoint used (resulting in a particular circumscription, position and rank) a name that is one taxonomist's synonym may be another taxonomist's correct name (and vice versa ). Synonyms may arise whenever the same taxon is described and named more than once, independently. They may also arise when existing taxa are changed, as when two taxa are joined to become one,

2975-412: Is based on size, the female being the largest and the reproductive male being the second largest. The rest of the group is made up of progressively smaller males that do not breed and have no functioning gonads. If the female dies, in many cases, the reproductive male gains weight and becomes the female for that group. The largest non-breeding male then sexually matures and becomes the reproductive male for

3060-408: Is completely absent in terrestrial vertebrates. Protandrous fishes include teleost species in the families Pomacentridae , Sparidae , and Gobiidae . A common example of a protandrous species are clownfish , which have a very structured society. In the species Amphiprion percula , there are zero to four individuals excluded from breeding and a breeding pair living in a sea anemone . Dominance

3145-436: Is decreased with age, the latter seems to be rare in the field. An example of territoriality favoring protogyny occurs when there is a need to protect their habitat and being a large male is advantageous for this purpose. In the mating aspect, a large male has a higher chance of mating, while this has no effect on the female mating fitness. Thus, he suggests that female fecundity has more impact on sequential hermaphroditism than

3230-692: Is found from Baffin Island , Labrador and Greenland to Arctic Russia , including Iceland , Scandinavia and the British Isles . Further south, it is found from the Sierra Nevada in southern Spain to the eastern Carpathians, including lower ranges such as the Massif Central . In the Arctic, M. stellaris may occur down to sea level. Within the British Isles, M. stellaris

3315-483: Is hypothesized that the mating system can determine whether it is more selectively advantageous to be a male or female when an organism's body is larger. Protogyny is the most common form of hermaphroditism in fish in nature. About 75% of the 500 known sequentially hermaphroditic fish species are protogynous and often have polygynous mating systems. In these systems, large males use aggressive territorial defense to dominate female mating. This causes small males to have

3400-410: Is not correct for the circumscription , position, and rank of the taxon as considered in the particular botanical publication. It is always "a synonym of the correct scientific name", but which name is correct depends on the taxonomic opinion of the author. In botany the various kinds of synonyms are: In botany, although a synonym must be a formally accepted scientific name (a validly published name):

3485-413: Is often expanded in taxonomic literature to include pro parte (or "for part") synonyms. These are caused by splits and circumscriptional changes. They are usually indicated by the abbreviation "p.p." For example: Protandry Sequential hermaphroditism (called dichogamy in botany ) is one of the two types of hermaphroditism , the other type being simultaneous hermaphroditism . It occurs when

Micranthes stellaris - Misplaced Pages Continue

3570-411: Is useful to have synonyms mentioned as such after the current scientific name, so as to avoid confusion. For example, if the much-advertised name change should go through and the scientific name of the fruit fly were changed to Sophophora melanogaster , it would be very helpful if any mention of this name was accompanied by "(syn. Drosophila melanogaster )". Synonyms used in this way may not always meet

3655-472: The Swiss Alps . In the Sierra Nevada of southern Spain, it lives at up to 3,350 m (10,990 ft). Micranthes stellaris lives in damp environments, such as wet flushes, beside streams or springs, or on wet rock ledges. It is self-compatible , but its flowers are protandrous , and are usually pollinated by flies . Synonym (taxonomy) Unlike synonyms in other contexts, in taxonomy

3740-497: The British Isles. The subspecies in the Alpide belt and other mountains in southern Europe is often called M. stellaris subsp. alpigena , but an older name has priority – M. stellaris subsp. robusta . The name M. stellaris subsp. prolifera is used for plants from the south-eastern Alps which have few flowers but produce bulbils along the stems. Micranthes stellaris has an Arctic–alpine distribution . It

3825-488: The age structures of the population. The size-advantage model predicts that sex change would only be absent if the relationship between size/age with reproductive potential is identical in both sexes. With this prediction one would assume that hermaphroditism is very common, but this is not the case. Sequential hermaphroditism is very rare and according to scientists this is due to some cost that decreases fitness in sex changers as opposed to those who do not change sex. Some of

3910-488: The authors have inspected the original material; a . that they take on the responsibility for the act of synonymizing the taxa. The accurate use of scientific names, including synonyms, is crucial in biomedical and pharmacological research involving plants. Failure to use correct botanical nomenclature can lead to ambiguity, hinder reproducibility of results, and potentially cause errors in medicine. Best practices for publication suggest that researchers should provide

3995-419: The beginning of § Zoology . The two are related, with only one word difference between their names.) For example, the scientific name of the red imported fire ant , Solenopsis invicta was published by Buren in 1972, who did not know that this species was first named Solenopsis saevissima wagneri by Santschi in 1916; as there were thousands of publications using the name invicta before anyone discovered

4080-643: The benefits of large inflorescences from the consequences of geitonogamy and pollen discounting. Such a decoupling would provide a significant reproductive advantage through increased pollinator visitation and siring success. It has been demonstrated experimentally that dichogamy both reduced rates of self-fertilization and enhanced outcross siring success through reductions in geitonogamy and pollen discounting, respectively. The influence of inflorescence size on this siring advantage shows bimodal distribution, with increased siring success with both small and large display sizes. The duration of stigmatic receptivity plays

4165-417: The capacity for sex change in either direction between male and female or female and male, potentially repeatedly during their lifetime. These various types of sequential hermaphroditism may indicate that there is no advantage based on the original sex of an individual organism. Those that change gonadal sex can have both female and male germ cells in the gonads or can change from one complete gonadal type to

4250-574: The conversion of testosterone into oestradiol , which is irreversible. It has been discovered that the aromatase pathway mediates sex change in both directions in organisms. Many studies also involve understanding the effect of aromatase inhibitors on sex change. One such study was performed by Kobayashi et al. In their study they tested the role of estrogens in male three-spot wrasses ( Halichoeres trimaculatus ). They discovered that fish treated with aromatase inhibitors showed decreased gonodal weight, plasma estrogen level and spermatogonial proliferation in

4335-421: The correct name is included among synonyms, although as first among equals it is the "senior synonym": Scientific papers may include lists of taxa, synonymizing existing taxa and (in some cases) listing references to them. The status of a synonym may be indicated by symbols, as for instance in a system proposed for use in paleontology by Rudolf Richter. In that system a v before the year would indicate that

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4420-649: The currently accepted binomial with author citation, relevant synonyms, and the accepted family name according to the Angiosperm Phylogeny Group III classification. This practice ensures clear communication, allows proper linking of research to existing literature, and provides insight into phylogenetic relationships that may be relevant to shared chemical constituents or physiological effects. Online databases now make it easy for researchers to access correct nomenclature and synonymy information for plant species. The traditional concept of synonymy

4505-769: The evolution of floral display size may represent a compromise between maximizing pollinator visitation and minimizing geitonogamy and pollen discounting (Barrett et al., 1994). Protandry may be particularly relevant to this compromise, because it often results in an inflorescence structure with female phase flowers positioned below male phase flowers. Given the tendency of many insect pollinators to forage upwards through inflorescences, protandry may enhance pollen export by reducing between-flower interference. Furthermore, this enhanced pollen export should increase as floral display size increases, because between-flower interference should increase with floral display size. These effects of protandry on between-flower interference may decouple

4590-508: The family Labridae. Wrasses are found around the world in all marine habitats and tend to bury themselves in sand at night or when they feel threatened. In wrasses, the larger of a mating pair is the male, while the smaller is the female. In most cases, females and immature males have a uniform color while the male has the terminal bicolored phase. Large males hold territories and try to pair spawn, while small to mid-size initial-phase males live with females and group spawn . In other words, both

4675-405: The family Pomacentridae was gonochoristic (single-sexed), indicating that protandry evolved within the family. Therefore, because other families also contain protandrous species, protandry likely has evolved multiple times. Other examples of protandrous animals include: Protogynous hermaphrodites are animals that are born female and at some point in their lifespan change sex to male. Protogyny

4760-402: The group. Other protandrous fishes can be found in the classes clupeiformes , siluriformes , stomiiformes . Since these groups are distantly related and have many intermediate relatives that are not protandrous, it strongly suggests that protandry evolved multiple times. Phylogenies support this assumption because ancestral states differ for each family. For example, the ancestral state of

4845-531: The hypotheses proposed for the dearth of hermaphrodites are the energetic cost of sex change, genetic and/or physiological barriers to sex change, and sex-specific mortality rates. In 2009, Kazanciglu and Alonzo found that dioecy was only favored when the cost of changing sex was very large. This indicates that the cost of sex change does not explain the rarity of sequential hermaphroditism by itself. The size-advantage model also explains under which mating systems protogyny or protandry would be more adaptive. In

4930-461: The initial- and terminal-phase males can breed, but they differ in the way they do it. In the California sheephead ( Semicossyphus pulcher ), a type of wrasse, when the female changes to male, the ovaries degenerate and spermatogenic crypts appear in the gonads. The general structure of the gonads remains ovarian after the transformation and the sperm is transported through a series of ducts on

5015-401: The junior synonym. (Incidentally, this species has since been reclassified and currently resides in the genus Bubo , as Bubo scandiacus ). One basic principle of zoological nomenclature is that the earliest correctly published (and thus available ) name, the senior synonym, by default takes precedence in naming rights and therefore, unless other restrictions interfere, must be used for

5100-430: The mountains of southern Europe. Micranthes stellaris grows as a leaf rosette , which produces a generally leafless stem up to 20 centimetres (7.9 in) tall. The leaves are toothed and somewhat fleshy, ovate or obovate, and without an obvious petiole . They are typically 3 cm (1.2 in) long (varying from 1 to 5 centimetres or 0.4 to 2.0 inches), with a cuneate (wedge-shaped) base. The flowers are borne in

5185-495: The opposite sex are already present. Sequential hermaphroditism in plants is the process in which a plant changes its sex during its lifetime. Sequential hermaphroditism in plants is very rare. There are less than 0.1% of recorded cases in which plant species entirely change their sex. The Patchy Environment Model and Size Dependent Sex Allocation are the two environmental factors which drive sequential hermaphroditism in plants. The Patchy Environment Model states that plants maximize

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5270-405: The organism's sex changes at some point in its life. A sequential hermaphrodite produces eggs (female gametes ) and sperm (male gametes ) at different stages in life. Sequential hermaphroditism occurs in many fish , gastropods , and plants. Species that can undergo these changes do so as a normal event within their reproductive cycle, usually cued by either social structure or the achievement of

5355-459: The other during their last life stage. In plants, individual flowers are called dichogamous if their function has the two sexes separated in time, although the plant as a whole may have functionally male and functionally female flowers open at any one moment. A flower is protogynous if its function is first female, then male, and protandrous if its function is first male then female. It used to be thought that this reduced inbreeding , but it may be

5440-411: The other sex at about the same age, then siblings are highly likely to be the same sex at any given time. This should dramatically reduce the likelihood of inbreeding. Both protandry and protogyny are known to help prevent inbreeding in plants, and many examples of sequential hermaphroditism attributable to inbreeding prevention have been identified in a wide variety of animals. The proximate cause of

5525-474: The periphery of the gonad and oviduct . Here, sex change is age-dependent. For example, the California sheephead stays a female for four to six years before changing sex since all California sheephead are born female. Bluehead wrasses begin life as males or females, but females can change sex and function as males. Young females and males start with a dull initial-phase coloration before progressing into

5610-536: The rules of nomenclature; as for example when an older name is (re)discovered which has priority over the current name. Speaking in general, name changes for nomenclatural reasons have become less frequent over time as the rules of nomenclature allow for names to be conserved, so as to promote stability of scientific names. In zoological nomenclature, codified in the International Code of Zoological Nomenclature , synonyms are different scientific names of

5695-408: The same taxonomic rank that pertain to that same taxon . For example, a particular species could, over time, have had two or more species-rank names published for it, while the same is applicable at higher ranks such as genera, families, orders, etc. In each case, the earliest published name is called the senior synonym , while the later name is the junior synonym . In the case where two names for

5780-409: The same rank with the same type specimen , genus-group taxa of the same rank with the same type species or if their type species are themselves objective synonyms, of family-group taxa with the same type genus, etc. In the case of subjective synonyms , there is no such shared type, so the synonymy is open to taxonomic judgement, meaning that there is room for debate: one researcher might consider

5865-534: The same species, but this name had never been used after 1899 and was fixed as a nomen oblitum under this rule by Falkner et al. 2002. Such a reversal of precedence is also possible if the senior synonym was established after 1900, but only if the International Commission on Zoological Nomenclature (ICZN) approves an application. (Here the C in ICZN stands for Commission, not Code as it does at

5950-407: The same taxon have been published simultaneously, the valid name is selected accorded to the principle of the first reviser such that, for example, of the names Strix scandiaca and Strix noctua (Aves), both published by Linnaeus in the same work at the same date for the taxon now determined to be the snowy owl , the epithet scandiaca has been selected as the valid name, with noctua becoming

6035-402: The sex reversal process by being synthesized as Leydig cells replicate and differentiate. Thus, the synthesis of sex steroids coincides with gonadal remodeling, which is triggered by MMPs produced by germinal epithelial tissue. These results suggests that MMPs and changes in steroid levels play a large role in sequential hermaphroditism in teleosts. Sequential hermaphrodites almost always have

6120-493: The strict definitions of the term "synonym" in the formal rules of nomenclature which govern scientific names (see below) . Changes of scientific name have two causes: they may be taxonomic or nomenclatural. A name change may be caused by changes in the circumscription, position or rank of a taxon, representing a change in taxonomic, scientific insight (as would be the case for the fruit fly, mentioned above). A name change may be due to purely nomenclatural reasons, that is, based on

6205-431: The style of the female flower elongating, then later in the male phase the anthers shedding pollen. Historically, dichogamy has been regarded as a mechanism for reducing inbreeding . However, a survey of the angiosperms found that self-incompatible (SI) plants, which are incapable of inbreeding, were as likely to be dichogamous as were self-compatible (SC) plants. This finding led to a reinterpretation of dichogamy as

6290-401: The synonymy, the ICZN, in 2001, ruled that invicta would be given precedence over wagneri . To qualify as a synonym in zoology, a name must be properly published in accordance with the rules. Manuscript names and names that were mentioned without any description ( nomina nuda ) are not considered as synonyms in zoological nomenclature. In botanical nomenclature , a synonym is a name that

6375-406: The taxon. However, junior synonyms are still important to document, because if the earliest name cannot be used (for example, because the same spelling had previously been used for a name established for another taxon), then the next available junior synonym must be used for the taxon. For other purposes, if a researcher is interested in consulting or compiling all currently known information regarding

6460-415: The teleost Synbranchus marmoratus found that metalloproteinases (MMPs) were involved in gonadal remodeling. In this process, the ovaries degenerated and were slowly replaced by the germinal male tissue. In particular, the action of MMPs induced significant changes in the interstitial gonadal tissue, allowing for reorganization of germinal epithelial tissue. The study also found that sex steroids help in

6545-421: The temporal overlap between stigma and anthers within an inflorescence. Large inflorescences attract more pollinators, potentially enhancing reproductive success by increasing pollen import and export. However, large inflorescences also increase the opportunities for both geitonogamy and pollen discounting, so that the opportunity for between-flower interference increases with inflorescence size. Consequently,

6630-406: The testis as well as increased androgen levels. Their results suggest that estrogens are important in the regulation of spermatogenesis in this protogynous hermaphrodite. Previous studies have also investigated sex reversal mechanisms in teleost fish. During sex reversal, their whole gonads including the germinal epithelium undergoes significant changes, remodeling, and reformation. One study on

6715-673: The transfer of pollen between flowers of the same individual. In contrast to within-flower interference, geitonogamy necessarily involves the same processes as outcrossing: pollinator attraction, reward provisioning, and pollen removal. Therefore, between-flower interference not only carries the cost of self-fertilization ( inbreeding depression ), but also reduces the amount of pollen available for export (so-called "pollen discounting" ). Because pollen discounting diminishes outcross siring success, interference avoidance may be an important evolutionary force in floral biology. Dichogamy may reduce between-flower interference by reducing or eliminating

6800-479: The two (or more) types to refer to one and the same taxon, another might consider them to belong to different taxa. For example, John Edward Gray published the name Antilocapra anteflexa in 1855 for a species of pronghorn , based on a pair of horns. However, it is now commonly accepted that his specimen was an unusual individual of the species Antilocapra americana published by George Ord in 1815. Ord's name thus takes precedence, with Antilocapra anteflexa being

6885-405: The two species, and while Ne was lower in the instant for the sex-changer, they were similar over a relatively short time horizon. The ability of these organisms to change biological sex has allowed for better reproductive success based on the ability for certain genes to pass down more easily from generation to generation. The change in sex also allows for organisms to reproduce if no individuals of

6970-440: The use of resources, if the combination of size and fitness for a certain sex is more beneficial, the plant will change to that sex. Evolutionarily, sequential hermaphrodites emerged as certain species obtained a reproductive advantage by changing their sex. Arisaema triphyllum (Jack in the pulpit) is a plant species which is commonly cited as exercising sequential hermaphroditism. As A. triphyllum grows, it develops from

7055-405: The use of their resources by changing their sex. For example, if a plant benefits more from the resources of a given environment in a certain sex, it will change to that sex. Furthermore, Size Dependent Sex Allocation outlines that in sequential hermaphroditic plants, it is preferable to change sexes in a way that maximizes their overall fitness compared to their size over time. Similar to maximizing

7140-545: Was established for a group of terrestrial snails containing as its type species the Burgundy or Roman snail Helix pomatia —since Helix pomatia was already the type species for the genus Helix Linnaeus, 1758, the genus Pomatia was an objective synonym (and useless). On the same occasion, Helix is also a synonym of Pomatia , but it is older and so it has precedence. At the species level, subjective synonyms are common because of an unexpectedly large range of variation in

7225-422: Was less likely to occur when the size advantage is stronger than other advantages. Warner suggests that selection for protandry may occur in populations where female fecundity is augmented with age and individuals mate randomly. Selection for protogyny may occur where there are traits in the population that depress male fecundity at early ages (territoriality, mate selection or inexperience) and when female fecundity

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