Myth and ritual are two central components of religious practice. Although myth and ritual are commonly united as parts of religion,
the exact relationship between them has been a matter of controversy
among scholars. One of the approaches to this problem is "the myth and
ritual, or myth-ritualist, theory," held notably by the so-called Cambridge Ritualists, which holds that "myth does not stand by itself but is tied to ritual." This theory is still disputed; many scholars now believe that myth and ritual share common paradigms, but not that one developed from the other.
Overview
The "myth and ritual school" is the name given to a series of authors who have focused their philological studies on the "ritual purposes of myths." Some of these scholars (e.g., W. Robertson-Smith, James George Frazer, Jane Ellen Harrison, S. H. Hooke) supported the "primacy of ritual" hypothesis, which claimed that "every myth is derived from a particular ritual and that the syntagmatic quality of myth is a reproduction of the succession of ritual act."
Following World War II, the semantic study of myth and ritual, particularly by Bill Stanner and Victor Turner,
has supported a connection between myth and ritual. However, it has not
supported the notion that one preceded and produced the other, as
supporters of the "primacy of ritual" hypothesis would claim. According
to the currently dominant scholarly view, the link between myth and
ritual is that they share common paradigms.
Ritual from myth
One possibility immediately presents itself: perhaps ritual arose from myth. Many religious rituals—notably Passover among Jews, Christmas and Easter among Christians, and the Hajj among Muslims—commemorate, or involve commemoration of, events in religious literature.
E. B. Tylor
Leaving
the sphere of historical religions, the ritual-from-myth approach often
sees the relationship between myth and ritual as analogous to the
relationship between science and technology. The pioneering
anthropologist Edward Burnett Tylor is the classic exponent of this view. He saw myth as an attempt to explain the world: for him, myth was a sort of proto-science.
Ritual is secondary: just as technology is an application of science,
so ritual is an application of myth—an attempt to produce certain
effects, given the supposed nature of the world: "For Tylor, myth
functions to explain the world as an end in itself. Ritual applies that
explanation to control the world." A ritual always presupposes a preexisting myth: in short, myth gives rise to ritual.
Myth from ritual (primacy of ritual)
Against
the intuitive idea that ritual reenacts myth or applies mythical
theories, many 19th-century anthropologists supported the opposite
position: that myth and religious doctrine result from ritual. This is
known as the "primacy of ritual" hypothesis.
William Robertson Smith
This view was asserted for the first time by the bible scholar William Robertson Smith. The scholar Meletinsky notes that Smith introduced the concept "dogmatically." In his Lectures on the Religion of the Semites
(1889), Smith draws a distinction between ancient and modern religion:
in modern religion, doctrine is central; in ancient religion, ritual is
central.
On the whole, Smith argues, ancients tended to be conservative with
regard to rituals, making sure to pass them down faithfully. In
contrast, the myths that justified those rituals could change. In fact,
according to Smith, many of the myths that have come down to us arose
"after the original, nonmythic reason [...] for the ritual had somehow
been forgotten."
As an example, Smith gives the worship of Adonis.
Worshipers mourned Adonis's mythical death in a ritual that coincided
with the annual withering of the vegetation. According to Smith, the
ritual mourning originally had a nonmythical explanation: with the
annual withering of plants, "the worshippers lament out of natural
sympathy [...] just as modern man is touched with melancholy at the
falling of autumn leaves."[10]
Once worshipers forgot the original, nonmythical reason for the
mourning ritual, they created "the myth of Adonis as the dying and
rising god of vegetation [...] to account for the ritual."
Stanley Edgar Hyman
In his essay "The Ritual View of Myth and the Mythic," (1955) Stanley Edgar Hyman makes an argument similar to Smith's:
"In Fiji [...] the physical
peculiarities of an island with only one small patch of fertile soil are
explained by a myth telling how Mberewalaki, a culture hero, flew into a
passion at the misbehavior of the people of the island and hurled all
the soil he was bringing them in a heap, instead of laying it out
properly. Hocart points out that the myth is used aetiologically to
explain the nature of the island, but did not originate in that attempt.
The adventures of Mberewalaki originated, like all mythology, in ritual
performance, and most of the lore of Hocart's Fijian informants
consisted of such ritual myths. When they get interested in the
topology of the island or are asked about it, Hocart argues, they do
precisely what we would do, which is ransack their lore for an answer."
Here Hyman argues against the etiological interpretation of myth,
which says that myths originated from attempts to explain the origins (etiologies)
of natural phenomena. If true, the etiological interpretation would
make myth older than, or at least independent of, ritual—as E.B. Tylor
believes it is. But Hyman argues that people use myth for etiological
purposes only after myth is already in place: in short, myths didn't
originate as explanations of natural phenomena. Further, Hyman argues,
myth originated from ritual performance. Thus, ritual came before myth,
and myth depends on ritual for its existence until it gains an
independent status as an etiological story.
James Frazer
The famous anthropologist Sir James George Frazer
claimed that myth emerges from ritual during the natural process of
religious evolution. Many of his ideas were inspired by those of Robertson Smith. In The Golden Bough
(1890; 1906–1915), Frazer famously argues that man progresses from
belief in magic (and rituals based on magic), through belief in
religion, to science. His argument is as follows.
Man starts out with a reflexive belief in a natural law. He
thinks he can influence nature by correctly applying this law: "In magic
man depends on his own strength to meet the difficulties and dangers
that beset him on every side. He believes in a certain established order
of nature on which he can surely count, and which he can manipulate for
his own ends."
However, the natural law man imagines—namely, magic—does not
work. When he sees that his pretended natural law is false, man gives up
the idea of a knowable natural law and "throws himself humbly on the
mercy of certain great invisible beings behind the veil of nature, to
whom he now ascribes all those far-reaching powers which he once
arrogated to himself."
In other words, when man loses his belief in magic, he justifies his
formerly magical rituals by saying that they reenact myths or honor
mythical beings. According to Frazer,
"myth changes while custom remains
constant; men continue to do what their fathers did before them, though
the reasons on which their fathers acted have been long forgotten. The
history of religion is a long attempt to reconcile old custom with new
reason, to find a sound theory for an absurd practice."
Jane Ellen Harrison and S. H. Hooke
The classicist Jane Ellen Harrison and the biblical scholar S. H. Hooke
regarded myth as intimately connected to ritual. However, "against
Smith," they "vigorously deny" that myth's main purpose is to justify a
ritual by giving an account of how it first arose (e.g., justifying the
Adonis worshipers' ritual mourning by attributing it to Adonis's
mythical death).
Instead, these scholars think a myth is largely just a narrative
description of a corresponding ritual: according to Harrison, "the
primary meaning of myth ... is the spoken correlative of the acted rite,
the thing done."
Harrison and Hooke gave an explanation for why ancients would
feel the need to describe the ritual in a narrative form. They suggest
that the spoken word, like the acted ritual, was considered to have
magical potency: "The spoken word had the efficacy of an act."
Like Frazer, Harrison believed that myths could arise as the
initial reason a ritual was forgotten or became diluted. As an example,
she cited rituals that center on the annual renewal of vegetation. Such
rituals often involve a participant who undergoes a staged death and
resurrection. Harrison argues that the ritual, although "performed
annually, was exclusively initiatory";
it was performed on people to initiate them into their roles as
full-standing members of society. At this early point, the "god" was
simply "the projection of the euphoria produced by the ritual."
Later, however, this euphoria became personified as a distinct god, and
this god later became the god of vegetation, for "just as the initiates
symbolically died and were reborn as fully fledged members of society,
so the god of vegetation and in turn crops literally died and were
reborn." In time, people forgot the ritual's initiatory function and only remembered its status as a commemoration of the Adonis myth.
Myth and ritual as non-coextensive
Not
all students of mythology think ritual emerged from myth or myth
emerged from ritual: some allow myths and rituals a greater degree of
freedom from one another. Although myths and rituals often appear
together, these scholars do not think every myth has or had a
corresponding ritual, or vice versa.
Walter Burkert
The classicist Walter Burkert believes myths and rituals were originally independent.
When myths and rituals do come together, he argues, they do so to
reinforce each other. A myth that tells how the gods established a
ritual reinforces that ritual by giving it divine status: "Do this
because the gods did or do it."
A ritual based on a mythical event makes the story of that event more
than a mere myth: the myth becomes more important because it narrates an
event whose imitation is considered sacred.
Furthermore, Burkert argues that myth and ritual together serve a "socializing function."
As an example, Burkert gives the example of hunting rituals. Hunting,
Burkert argues, took on a sacred, ritualistic aura once it ceased to be
necessary for survival: "Hunting lost its basic function with the
emergence of agriculture some ten thousand years ago. But hunting ritual
had become so important that it could not be given up."
By performing the ritual of hunting together, an ancient society bonded
itself together as a group, and also provided a way for its members to
vent their anxieties over their own aggressiveness and mortality.
Bronisław Malinowski
Like William Smith, the anthropologist Bronisław Malinowski argued in his essay Myth in Primitive Psychology
(1926) that myths function as fictitious accounts of the origin of
rituals, thereby providing a justification for those rituals: myth
"gives rituals a hoary past and thereby sanctions them."
However, Malinowski also points out that many cultural practices
besides ritual have related myths: for Malinowski, "myth and ritual are
therefore not coextensive." In other words, not all myths are outgrowths of ritual, and not all rituals are outgrowths of myth.
Mircea Eliade
Like Malinowski, the religious scholar Mircea Eliade
thinks one important function of myth is to provide an explanation for
ritual. Eliade notes that, in many societies, rituals are considered
important precisely because they were established by the mythical gods
or heroes. Eliade approvingly quotes Malinowski's claim that a myth is "a narrative resurrection of a primeval reality." Eliade adds: "Because myth relates the gesta [deeds] of Supernatural Beings [...] it becomes the exemplary model for all significant human actions."
Traditional man sees mythical figures as models to be imitated.
Therefore, societies claim that many of their rituals were established
by mythical figures, thereby making the rituals seem all the more
important. However, also like Malinowski, Eliade notes that societies
use myths to sanction many kinds of activities, not just rituals: "For
him, too, then, myth and ritual are not coextensive."
Eliade goes beyond Malinowski by giving an explanation for why
myth can confer such an importance upon ritual: according to Eliade,
"when [ritually] [re-]enacted myth acts as a time machine, carrying one
back to the time of the myth and thereby bringing one closer to god."
But, again, for Eliade myth and ritual are not coextensive: the same
return to the mythical age can be achieved simply by retelling a myth,
without any ritual reenactment. According to Eliade, traditional man
sees both myths and rituals as vehicles for "eternal return" to the
mythical age (see Eternal return (Eliade)):
"In imitating the exemplary acts of a god or of a mythic hero,
or simply by recounting their adventures, the man of an archaic society
detaches himself from profane time and magically re-enters the Great
Time, the sacred time."
Recital of myths and enactment of rituals serve a common purpose: they are two different means to remain in sacred time.
Myth is a folklore genre consisting of narratives that play a fundamental role in a society, such as foundational tales or origin myths. The main characters in myths are usually non-humans, such as gods, demigods, and other supernatural figures. However, others also include humans, animals, or combinations in their classification of myth. Stories of everyday human beings, although often of leaders of some type, are usually contained in legends, as opposed to myths.
Myths are sometimes distinguished from legends in that myths deal with
gods, usually have no historical basis, and are set in a world of the
remote past, very different from that of the present.
Myths are often endorsed by rulers and priests or priestesses and are closely linked to religion or spirituality.
Many societies group their myths, legends, and history together,
considering myths and legends to be true accounts of their remote past. In particular, creation myths take place in a primordial age when the world had not achieved its later form. Other myths explain how a society's customs, institutions, and taboos were established and sanctified. There is a complex relationship between recital of myths and the enactment of rituals.
Since the term myth is widely used to imply that a story is not objectively true,
the identification of a narrative as a myth can be highly
controversial: many adherents of religions view their own religion's
stories as true,
and therefore object to those stories being characterized as myths,
while seeing the stories of other religions as being myth. As such, some
scholars label all religious narratives as myths for practical
reasons, such as to avoid depreciating any one tradition because
cultures interpret each other differently relative to one another.
Other scholars avoid using the term "myth" altogether and instead
utilize different terms like "sacred history", "holy story", or simply
"history" to avoid placing pejorative overtones on any sacred narrative.
Definitions of myth vary to some extent among scholars, though Finnish folkloristLauri Honko offers a widely-cited definition:
Myth, a story of the gods, a religious account of the beginning of the world, the creation,
fundamental events, the exemplary deeds of the gods as a result of
which the world, nature and culture were created together with all parts
thereof and given their order, which still obtains. A myth expresses
and confirms society's religious values and norms, it provides a pattern
of behavior to be imitated, testifies to the efficacy of ritual with its practical ends and establishes the sanctity of cult.
Another definition of myth comes from myth criticism theorist and professor José Manuel Losada.
According to Cultural myth criticism, the studies of myth must
understand and explain a global and imaginary reality and be able to
better understand contemporary culture.
Myth is an oral, symbolic, evolutionary and apparently simple account (in the sense of a tale, a diegesis, or a series of narrative and representative actions) of an extraordinary experience or event with a transcendental
and personal referent that shows social classification. Considered, in
principle, as bereft of historical testimony, myth is composed by a
series of constant or invariable cultural semantic elements which can be
reduced to themes, and is endowed with a conflictive (it invariably
contains a trial or ordeal), functional character (understood as the
transmission of common values and beliefs, and the provision of factual
schemata of rites and actions) and etiological nature (expressing in
some way a particular or universal cosmogony or eschatology).
However, while myth and other folklore genres may overlap, myth is often thought to differ from genres such as legend and folktale in that neither are considered to be sacred narratives. Some kinds of folktales, such as fairy stories, are not considered true by anyone, and may be seen as distinct from myths for this reason. Main characters in myths are usually gods, demigods or supernatural humans, while legends generally feature humans as their main characters. However, many exceptions or combinations exist, as in the Iliad, Odyssey and Aeneid.
Moreover, as stories spread between cultures or as faiths change, myths
can come to be considered folktales, their divine characters recast as
either as humans or demihumans such as giants, elves and faeries. Conversely, historical and literary material may acquire mythological qualities over time. For example, the Matter of Britain (the legendary history of Great Britain, especially those focused on King Arthur and the knights of the Round Table) and the Matter of France,
seem distantly to originate in historical events of the 5th and
8th-centuries respectively, and became mythologised over the following
centuries.
In colloquial use, the word myth can also be used of a collectively held belief that has no basis in fact, or any false story. This usage, which is often pejorative,
arose from labelling the religious myths and beliefs of other cultures
as incorrect, but it has spread to cover non-religious beliefs as well.
However, as commonly used by folklorists and academics in other relevant fields, such as anthropology, the term myth has no implication whether the narrative may be understood as true or otherwise.
Among biblical scholars of both the Old and New Testament, the word
"myth" has a technical meaning, in that it usually refers to "describe
the actions of the other‐worldly in terms of this world" such as the
Creation and the Fall.
Mythology
Opening lines of one of the Mabinogi myths from the Red Book of Hergest (written pre-13c, incorporating pre-Roman myths of Celtic gods): Gereint vab Erbin. Arthur a deuodes dala llys yg Caerllion ar Wysc... (Geraint the son of Erbin. Arthur was accustomed to hold his Court at Caerlleon upon Usk...)
Mythology can also refer to the study of myths and mythologies.
Mythography
The compilation or description of myths is sometimes known as mythography, a term which can also be used of a scholarly anthology of myths (or, confusingly, of the study of myths generally).
Key mythographers in the Classical tradition include:
Ovid (43 BCE–17/18 CE), whose tellings of myths have been profoundly influential;
Fabius Planciades Fulgentius, a Latin writer of the late-5th to early-6th centuries, whose Mythologies (Latin: Mitologiarum libri III) gathered and gave moralistic interpretations of a wide range of myths;
Renaissance scholar Natalis Comes, whose ten-book Mythologiae became a standard source for classical mythology in later Renaissance Europe.
Other prominent mythographies include the thirteenth-century Prose Edda attributed to the Icelander Snorri Sturluson, which is the main surviving survey of Norse Mythology from the Middle Ages.
Jeffrey G. Snodgrass (professor of anthropology at the Colorado State University) has termed India's Bhats as mythographers.
Myth criticism
Myth criticism is a system of anthropological interpretation of culture created by French philosopher Gilbert Durand.
Scholars have used myth criticism to explain the mythical roots of
contemporary fiction, which means that modern myth criticism needs to be
interdisciplinary.
Myth criticism, a discipline that
studies myths (mythology contains them, like a pantheon its statues), is
by nature interdisciplinary: it combines the contributions of literary
theory, the history of literature, the fine arts and the new ways of
dissemination in the age of communication. Likewise, it undertakes its
object of study from its interrelation with other human and social
sciences, in particular sociology, anthropology and economics.
The need for an approach, for a methodology that allows us to
understand the complexity of the myth and its manifestations in
contemporary times, is justified.
Mythos
Because myth is sometimes used in a pejorative sense, some scholars have opted to use the term mythos instead. However, mythos now more commonly refers to its Aristotelian
sense as a "plot point" or to a body of interconnected myths or
stories, especially those belonging to a particular religious or
cultural tradition. It is sometimes used specifically for modern, fictional mythologies, such as the world building of H. P. Lovecraft.
Mythopoeia (mytho- + -poeia, 'I make myth') was termed by J. R. R. Tolkien, amongst others, to refer to the "conscious generation" of mythology. It was notoriously also suggested, separately, by Nazi ideologist Alfred Rosenberg.
Etymology
Odysseus Overcome by Demodocus' Song, by Francesco Hayez, 1813–15
The word myth comes from Ancient Greekμῦθος (mȳthos), meaning 'speech, narrative, fiction, myth, plot'. In Anglicised
form, this Greek word began to be used in English (and was likewise
adapted into other European languages) in the early 19th century, in a
much narrower sense, as a scholarly term for "[a] traditional story,
especially one concerning the early history of a people or explaining a
natural or social phenomenon, and typically involving supernatural
beings or events."
In turn, Ancient Greek μυθολογία (mythología, 'story,' 'lore,' 'legends,' or 'the telling of stories') combines the word mȳthos with the suffix -λογία (-logia, 'study') in order to mean 'romance, fiction, story-telling.' Accordingly, Plato used mythología as a general term for 'fiction' or 'story-telling' of any kind.
The Greek term mythología was then borrowed into Late Latin, occurring in the title of Latin author Fulgentius' 5th-century Mythologiæ to denote what we now call classical mythology—i.e., Greco-Romanetiological stories involving their gods. Fulgentius' Mythologiæ explicitly treated its subject matter as allegories requiring interpretation and not as true events.
The Latin term was then adopted in Middle French as mythologie. Whether from French or Latin usage, English adopted the word mythology
in the 15th century, initially meaning 'the exposition of a myth or
myths,' 'the interpretation of fables,' or 'a book of such expositions'.
The word is first attested in John Lydgate's Troy Book (c. 1425).
From Lydgate until the 17th or 18th century, mythology was used to mean a moral, fable, allegory or a parable, or collection of traditional stories, understood to be false. It came eventually to be applied to similar bodies of traditional stories among other polytheistic cultures around the world.
Thus the word mythology entered the English language before the word myth. Johnson's Dictionary, for example, has an entry for mythology, but not for myth. Indeed, the Greek loanwordmythos (pl.mythoi) and Latinate mythus (pl. mythi) both appeared in English before the first example of myth in 1830.[67]
Meanings in Ancient Greece
The term μῦθος (mȳthos) appears in the works of Homer
and other poets of Homer's era, in which the term had several meanings:
'conversation,' 'narrative,' 'speech,' 'story,' 'tale,' and 'word.'
Similar to the related term λόγος (logos), mythos expresses whatever can be delivered in the form of words. These can be contrasted with Greek ἔργον (ergon, 'action,' 'deed,' or 'work'). However, the term mythos lacks an explicit distinction between true or false narratives.
In the context of Ancient Greek theatre, mythos referred to the myth, narrative, plot, and the story of a play. According to David Wiles, the Greek term mythos
in this era covered an entire spectrum of different meanings, from
undeniable falsehoods to stories with religious and symbolic
significance.
According to philosopher Aristotle (384–322 BCE), the spirit of a theatrical play was its mythos. The term mythos was also used for the source material of Greek tragedy. The tragedians of the era could draw inspiration from Greek mythology, a body of "traditional storylines" which concerned gods and heroes.
David Wiles observes that modern conceptions about Greek tragedy can be
misleading. It is commonly thought that the ancient audience members
were already familiar with the mythos behind a play, and could
predict the outcome of the play. However, the Greek dramatists were not
expected to faithfully reproduce traditional myths when adapting them for the stage. They were instead recreating the myths and producing new versions. Storytellers like Euripides (c. 480–406 BCE) relied on suspense to excite their audiences. In one of his works, Merope
attempts to kill her son's murderer with an axe, unaware that the man
in question is actually her son. According to an ancient description of
audience reactions to this work, the audience members were genuinely
unsure of whether she would commit filicide or she will be stopped in time. They rose to their feet in terror and caused an uproar.
David Wiles points that the traditional mythos of Ancient Greece, was primarily a part of its oral tradition. The Greeks of this era were a literate culture but produced no sacred texts. There were no definitive or authoritative versions of myths recorded in texts and preserved forever in an unchanging form.
Instead multiple variants of myths were in circulation. These variants
were adapted into songs, dances, poetry, and visual art. Performers of
myths could freely reshape their source material for a new work,
adapting it to the needs of a new audience or in response to a new
situation.
Children in Ancient Greece were familiar with traditional myths from an early age. According to the philosopher Plato (c. 428–347 BCE), mothers and nursemaids narrated myths and stories to the children in their charge: David Wiles describes them as a repository of mythological lore.
Bruce Lincoln has called attention to the apparent meaning of the terms mythos and logos in the works of Hesiod. In Theogony, Hesiod attributes to the Muses the ability to both proclaim truths and narrate plausible falsehoods (i.e., falsehoods which seem like real things). The verb used for narrating the falsehoods in the text is legein, which is etymologically associated with logos. There are two variants in the manuscript tradition for the verb used to proclaim truths. One variant uses gerusasthai, the other mythesasthai. The latter is a form of the verb mytheomai ('to speak,' 'to tell'), which is etymologically associated with mythos. In the Works and Days,
Hesiod describes his dispute with his brother Perses. He also announces
to his readers his intention to tell true things to his brother. The
verb he uses for telling the truth is mythesaimen, another form of mytheomai.
Lincoln draws the conclusion that Hesiod associated the "speech of mythos" (as Lincoln calls it) with telling the truth. While he associated the "speech of logos" with telling lies, and hiding one's true thoughts (dissimulation). This conclusion is strengthened by the use of the plural term logoi (the plural form of logos) elsewhere in Hesiod's works. Three times the term is associated with the term seductive and three times with the term falsehoods. In his genealogy of the gods, Hesiod lists logoi among the children of Eris,
the goddess personifying strife. Eris' children are ominous figures,
which personify various physical and verbal forms of conflict.
Comparative mythology is a systematic comparison of myths from
different cultures. It seeks to discover underlying themes that are
common to the myths of multiple cultures. In some cases, comparative
mythologists use the similarities between separate mythologies to argue
that those mythologies have a common source. This source may inspire
myths or provide a common "protomythology" that diverged into the
mythologies of each culture.
Functionalism
A number of commentators have argued that myths function to form and shape society and social behaviour. Eliade argued that one of the foremost functions of myth is to establish models for behavior
and that myths may provide a religious experience. By telling or
reenacting myths, members of traditional societies detach themselves
from the present, returning to the mythical age, thereby coming closer
to the divine.
Honko
asserted that, in some cases, a society reenacts a myth in an attempt
to reproduce the conditions of the mythical age. For example, it might
reenact the healing performed by a god at the beginning of time in order
to heal someone in the present. Similarly, Barthes
argued that modern culture explores religious experience. Since it is
not the job of science to define human morality, a religious experience
is an attempt to connect with a perceived moral past, which is in
contrast with the technological present.
Pattanaik defines mythology as "the subjective truth of people communicated through stories, symbols and rituals." He says, "Facts are everybody's truth. Fiction is nobody's truth. Myths are somebody's truth."
One theory claims that myths are distorted accounts of historical events.
According to this theory, storytellers repeatedly elaborate upon
historical accounts until the figures in those accounts gain the status
of gods. For example, the myth of the wind-god Aeolus may have evolved from a historical account of a king who taught his people to use sails and interpret the winds. Herodotus (fifth-century BCE) and Prodicus made claims of this kind. This theory is named euhemerism after mythologist Euhemerus (c. 320 BCE), who suggested that Greek gods developed from legends about human beings.
Allegory
Some theories propose that myths began as allegories for natural phenomena: Apollo represents the sun, Poseidon represents water, and so on. According to another theory, myths began as allegories for philosophical or spiritual concepts: Athena represents wise judgment, Aphrodite desire, and so on. Müller
supported an allegorical theory of myth. He believed myths began as
allegorical descriptions of nature and gradually came to be interpreted
literally. For example, a poetic description of the sea as "raging" was
eventually taken literally and the sea was then thought of as a raging
god.
Some thinkers claimed that myths result from the personification
of objects and forces. According to these thinkers, the ancients
worshiped natural phenomena, such as fire and air, gradually deifying
them. For example, according to this theory, ancients tended to view things as gods, not as mere objects. Thus, they described natural events as acts of personal gods, giving rise to myths.
According to the myth-ritual theory, myth is tied to ritual. In its most extreme form, this theory claims myths arose to explain rituals. This claim was first put forward by Smith,
who argued that people begin performing rituals for reasons not related
to myth. Forgetting the original reason for a ritual, they account for
it by inventing a myth and claiming the ritual commemorates the events
described in that myth. Frazer
argued that humans started out with a belief in magical rituals; later,
they began to lose faith in magic and invented myths about gods,
reinterpreting their rituals as religious rituals intended to appease
the gods.
The critical interpretation of myth began with the Presocratics. Euhemerus
was one of the most important pre-modern mythologists. He interpreted
myths as accounts of actual historical events, though distorted over
many retellings.
mixed, which concerns myths that show the interaction between two or
more of the previous categories and are particularly used in
initiations.
Plato famously condemned poetic myth when discussing education in the Republic.
His critique was primarily on the grounds that the uneducated might
take the stories of gods and heroes literally. Nevertheless, he
constantly referred to myths throughout his writings. As Platonism developed in the phases commonly called Middle Platonism and neoplatonism, writers such as Plutarch, Porphyry, Proclus, Olympiodorus, and Damascius wrote explicitly about the symbolic interpretation of traditional and Orphic myths.
Mythological themes were consciously employed in literature, beginning with Homer. The resulting work may expressly refer to a mythological background without itself becoming part of a body of myths (Cupid and Psyche). Medieval romance in particular plays with this process of turning myth into literature. Euhemerism,
as stated earlier, refers to the rationalization of myths, putting
themes formerly imbued with mythological qualities into pragmatic
contexts. An example of this would be following a cultural or religious
paradigm shift (notably the re-interpretation of pagan mythology following Christianization).
European Renaissance
This panel by Bartolomeo di Giovanni relates the second half of the Metamorphoses. In the upper left, Jupiter emerges from clouds to order Mercury to rescue Io.
Interest in polytheistic mythology revived during the Renaissance, with early works of mythography appearing in the sixteenth century, among them the Theologia Mythologica (1532).
The first modern, Western scholarly theories of myth appeared during the second half of the 19th century—at the same time as the word myth was adopted as a scholarly term in European languages. They were driven partly by a new interest in Europe's ancient past and vernacular culture, associated with Romantic Nationalism and epitomised by the research of Jacob Grimm
(1785–1863). This movement drew European scholars' attention not only
to Classical myths, but also material now associated with Norse mythology, Finnish mythology,
and so forth. Western theories were also partly driven by Europeans'
efforts to comprehend and control the cultures, stories and religions
they were encountering through colonialism. These encounters included both extremely old texts such as the SanskritRigveda and the SumerianEpic of Gilgamesh, and current oral narratives such as mythologies of the indigenous peoples of the Americas or stories told in traditional African religions.
The intellectual context for nineteenth-century scholars was profoundly shaped by emerging ideas about evolution.
These ideas included the recognition that many Eurasian languages—and
therefore, conceivably, stories—were all descended from a lost common
ancestor (the Indo-European language) which could rationally be reconstructed through the comparison of its descendant languages. They also included the idea that cultures might evolve in ways comparable to species.
In general, 19th-century theories framed myth as a failed or obsolete
mode of thought, often by interpreting myth as the primitive counterpart
of modern science within a unilineal framework that imagined that human cultures are travelling, at different speeds, along a linear path of cultural development.
Nature mythology
One of the dominant mythological theories of the latter 19th century was nature mythology, the foremost exponents of which included Max Müller and Edward Burnett Tylor.
This theory posited that "primitive man" was primarily concerned with
the natural world. It tended to interpret myths that seemed distasteful
to European Victorians—such as tales about sex, incest, or cannibalism—as being metaphors for natural phenomena like agricultural fertility.
Unable to conceive impersonal natural laws, early humans tried to
explain natural phenomena by attributing souls to inanimate objects,
thus giving rise to animism.
According to Tylor, human thought evolved through stages,
starting with mythological ideas and gradually progressing to scientific
ideas.
Müller also saw myth as originating from language, even calling myth a
"disease of language." He speculated that myths arose due to the lack of
abstract nouns and neuter gender in ancient languages. Anthropomorphicfigures of speech,
necessary in such languages, were eventually taken literally, leading
to the idea that natural phenomena were in actuality conscious beings or
gods. Not all scholars, not even all 19th-century scholars, accepted this view, however: Lucien Lévy-Bruhl claimed that "the primitive mentality is a condition of the human mind and not a stage in its historical development."
Recent scholarship, noting the fundamental lack of evidence for "nature
mythology" interpretations among people who actually circulated myths,
has likewise abandoned the key ideas of "nature mythology."
Myth and ritual
James George Frazer
saw myths as a misinterpretation of magical rituals, which were
themselves based on a mistaken idea of natural law. this idea was
central to the "myth and ritual" school of thought.
According to Frazer, humans begin with an unfounded belief in
impersonal magical laws. When they realize applications of these laws do
not work, they give up their belief in natural law in favor of a belief
in personal gods
controlling nature, thus giving rise to religious myths. Meanwhile,
humans continue practicing formerly magical rituals through force of
habit, reinterpreting them as reenactments of mythical events. Finally,
humans come to realize nature follows natural laws, and they discover
their true nature through science. Here again, science makes myth
obsolete as humans progress "from magic through religion to science."
Segal asserted that by pitting mythical thought against modern
scientific thought, such theories imply modern humans must abandon myth.
The earlier 20th century saw major work developing psychoanalytical approaches to interpreting myth, led by Sigmund Freud, who, drawing inspiration from Classical myth, began developing the concept of the Oedipus complex in his 1899 The Interpretation of Dreams. Jung
likewise tried to understand the psychology behind world myths. Jung
asserted that all humans share certain innate unconscious psychological
forces, which he called archetypes. He believed similarities between the myths of different cultures reveals the existence of these universal archetypes.
The mid-20th century saw the influential development of a structuralist theory of mythology, led by Lévi-Strauss.
Strauss argued that myths reflect patterns in the mind and interpreted
those patterns more as fixed mental structures, specifically pairs of
opposites (good/evil, compassionate/callous), rather than unconscious
feelings or urges. Meanwhile, Bronislaw Malinowski
developed analyses of myths focusing on their social functions in the
real world. He is associated with the idea that myths such as origin stories might provide a "mythic charter"—a legitimisation—for cultural norms and social institutions. Thus, following the Structuralist Era (c. 1960s–1980s), the predominant anthropological and sociological
approaches to myth increasingly treated myth as a form of narrative
that can be studied, interpreted, and analyzed like ideology, history,
and culture. In other words, myth is a form of understanding and telling
stories that are connected to power, political structures, and
political and economic interests.
These approaches contrast with approaches, such as those of Joseph Campbell and Eliade,
which hold that myth has some type of essential connection to ultimate
sacred meanings that transcend cultural specifics. In particular, myth
was studied in relation to history from diverse social sciences. Most of
these studies share the assumption that history and myth are not
distinct in the sense that history is factual, real, accurate, and
truth, while myth is the opposite.
In the 1950s, Barthes published a series of essays examining modern myths and the process of their creation in his book Mythologies, which stood as an early work in the emerging post-structuralist approach to mythology, which recognised myths' existence in the modern world and in popular culture.
The 20th century saw rapid secularisation in Western culture. This made Western scholars more willing to analyse narratives in the Abrahamic religions as myths; theologians such as Rudolf Bultmann argued that a modern Christianity needed to demythologize; and other religious scholars embraced the idea that the mythical status of Abrahamic narratives was a legitimate feature of their importance. This, in his appendix to Myths, Dreams and Mysteries, and in The Myth of the Eternal Return, Eliade attributed modern humans’ anxieties to their rejection of myths and the sense of the sacred.
[M]yth today has come to have
negative connotations which are the complete opposite of its meaning in a
religious context... In a religious context, however, myths are storied
vehicles of supreme truth, the most basic and important truths of all.
By them, people regulate and interpret their lives and find worth and
purpose in their existence. Myths put one in touch with sacred
realities, the fundamental sources of being, power, and truth. They are
seen not only as being the opposite of error but also as being clearly
distinguishable from stories told for entertainment and from the
workaday, domestic, practical language of a people. They provide answers
to the mysteries of being and becoming, mysteries which, as mysteries,
are hidden, yet mysteries which are revealed through story and ritual.
Myths deal not only with truth but with ultimate truth.
Twenty-first century
Both in 19th-century research, which tended to see existing records
of stories and folklore as imperfect fragments of partially lost myths,
and in 20th-century structuralist work, which sought to identify
underlying patterns and structures in often diverse versions of a given
myth, there had been a tendency to synthesise sources to attempt to
reconstruct what scholars supposed to be more perfect or underlying
forms of myths. From the late 20th century, however, researchers
influenced by postmodernism
tended instead to argue that each account of a given myth has its own
cultural significance and meaning, and argued that rather than
representing degradation from a once more perfect form, myths are
inherently plastic and variable.
There is, consequently, no such thing as the 'original version' or
'original form' of a myth. One prominent example of this movement was A. K. Ramanujan's essay "Three Hundred Ramayanas".
Correspondingly, scholars challenged the precedence that had once
been given to texts as a medium for mythology, arguing that other
media, such as the visual arts or even landscape and place-naming, could
be as or more important.
Scholars in the field of cultural studies
research how myth has worked itself into modern discourses.
Mythological discourse can reach greater audiences than ever before via
digital media. Various mythic elements appear in television, cinema and video games.
Although myth was traditionally transmitted through the oral
tradition on a small scale, the film industry has enabled filmmakers to
transmit myths to large audiences via film. In Jungian psychology myths are the expression of a culture or society’s goals, fears, ambitions and dreams.
The basis of modern visual storytelling is rooted in the
mythological tradition. Many contemporary films rely on ancient myths to
construct narratives. The Walt Disney Company is well-known among cultural study scholars for "reinventing" traditional childhood myths.
While many films are not as obvious as Disney fairy tales, the plots of
many films are based on the rough structure of myths. Mythological
archetypes, such as the cautionary tale regarding the abuse of
technology, battles between gods and creation stories, are often the
subject of major film productions. These films are often created under
the guise of cyberpunkaction films, fantasy, dramas and apocalyptic tales.
The asexual, all-female whiptail species Aspidoscelis neomexicanus (center), which reproduces via parthenogenesis, is shown flanked by two sexual species having males, A. inornatus (left) and A. tigris (right), which hybridized naturally to form A. neomexicanus.
Normal egg cells form in the process of meiosis and are haploid, with half as many chromosomes
as their mother's body cells. Haploid individuals, however, are usually
non-viable, and parthenogenetic offspring usually have the diploid
chromosome number. Depending on the mechanism involved in restoring the
diploid number of chromosomes, parthenogenetic offspring may have
anywhere between all and half of the mother's alleles. The offspring having all of the mother's genetic material are called full clones
and those having only half are called half clones. Full clones are
usually formed without meiosis. If meiosis occurs, the offspring will
get only a fraction of the mother's alleles since crossing over of DNA takes place during meiosis, creating variation.
Parthenogenetic offspring in species that use either the XY or the X0 sex-determination system have two X chromosomes and are female. In species that use the ZW sex-determination system,
they have either two Z chromosomes (male) or two W chromosomes (mostly
non-viable but rarely a female), or they could have one Z and one W
chromosome (female).
Parthenogenesis does not apply to isogamous or monogamous species.
A baby Komodo dragon, Varanus komodoensis,
produced through parthenogenesis. Komodo dragons are an example of a
species which can produce offspring both through sexual reproduction and
parthenogenesis.
Some species reproduce exclusively by parthenogenesis (such as the bdelloid rotifers),
while others can switch between sexual reproduction and
parthenogenesis. This is called facultative parthenogenesis (other terms
are cyclical parthenogenesis, heterogamy or heterogony). The switch between sexuality and parthenogenesis in such species may be triggered by the season (aphid, some gall wasps), or by a lack of males or by conditions that favour rapid population growth (rotifers and cladocerans like Daphnia).
In these species asexual reproduction occurs either in summer (aphids)
or as long as conditions are favourable. This is because in asexual
reproduction a successful genotype can spread quickly without being
modified by sex or wasting resources on male offspring who won't give
birth. In times of stress, offspring produced by sexual reproduction may
be fitter as they have new, possibly beneficial gene combinations. In
addition, sexual reproduction provides the benefit of meiotic
recombination between non-sister chromosomes, a process associated with
repair of DNA double-strand breaks and other DNA damages that may be
induced by stressful conditions.
Many taxa with heterogony have within them species that have lost
the sexual phase and are now completely asexual. Many other cases of
obligate parthenogenesis (or gynogenesis) are found among polyploids and
hybrids where the chromosomes cannot pair for meiosis.
The production of female offspring by parthenogenesis is referred to as thelytoky (e.g., aphids) while the production of males by parthenogenesis is referred to as arrhenotoky (e.g., bees). When unfertilized eggs develop into both males and females, the phenomenon is called deuterotoky.
Types and mechanisms
Parthenogenesis can occur without meiosis through mitotic oogenesis. This is called apomictic parthenogenesis.
Mature egg cells are produced by mitotic divisions, and these cells
directly develop into embryos. In flowering plants, cells of the gametophyte can undergo this process. The offspring produced by apomictic parthenogenesis are full clones of their mother. Examples include aphids.
Parthenogenesis involving meiosis is more complicated. In some cases, the offspring are haploid (e.g., male ants). In other cases, collectively called automictic parthenogenesis,
the ploidy is restored to diploidy by various means. This is because
haploid individuals are not viable in most species. In automictic
parthenogenesis, the offspring differ from one another and from their
mother. They are called half clones of their mother.
Automictic
The effects of central fusion and terminal fusion on heterozygosity
Automixis is a term that covers several reproductive mechanisms, some of which are parthenogenetic.
Diploidy might be restored by the doubling of the chromosomes
without cell division before meiosis begins or after meiosis is
completed. This is referred to as an endomitotic cycle. This may also happen by the fusion of the first two blastomeres.
Other species restore their ploidy by the fusion of the meiotic
products. The chromosomes may not separate at one of the two anaphases
(called restitutional meiosis) or the nuclei produced may fuse or one of the polar bodies may fuse with the egg cell at some stage during its maturation.
Some authors consider all forms of automixis sexual as they
involve recombination. Many others classify the endomitotic variants as
asexual and consider the resulting embryos parthenogenetic. Among these
authors, the threshold for classifying automixis as a sexual process
depends on when the products of anaphase I or of anaphase II are joined
together. The criterion for "sexuality" varies from all cases of
restitutional meiosis, to those where the nuclei fuse or to only those where gametes are mature at the time of fusion. Those cases of automixis that are classified as sexual reproduction are compared to self-fertilization in their mechanism and consequences.
The genetic composition of the offspring depends on what type of apomixis takes place. When endomitosis occurs before meiosis or when central fusion occurs (restitutional meiosis of anaphase I or the fusion of its products), the offspring get all to more than half of the mother's genetic material and heterozygosity is mostly preserved (if the mother has two alleles for a locus, it is likely that the offspring will get both). This is because in anaphase I
the homologous chromosomes are separated. Heterozygosity is not
completely preserved when crossing over occurs in central fusion. In the case of pre-meiotic doubling, recombination, if it happens, occurs between identical sister chromatids.
If terminal fusion (restitutional meiosis of anaphase II
or the fusion of its products) occurs, a little over half the mother's
genetic material is present in the offspring and the offspring are
mostly homozygous. This is because at anaphase II the sister chromatids
are separated and whatever heterozygosity is present is due to crossing
over. In the case of endomitosis after meiosis, the offspring is
completely homozygous and has only half the mother's genetic material.
This can result in parthenogenetic offspring being unique from each other and from their mother.
Sex of the offspring
In
apomictic parthenogenesis, the offspring are clones of the mother and
hence (except for aphids) are usually female. In the case of aphids,
parthenogenetically produced males and females are clones of their
mother except that the males lack one of the X chromosomes (XO).
When meiosis is involved, the sex of the offspring will depend on the type of sex determination system and the type of apomixis. In species that use the XY sex-determination system, parthenogenetic offspring will have two X chromosomes and are female. In species that use the ZW sex-determination system the offspring genotype may be one of ZW (female), ZZ (male), or WW (non-viable in most species but a fertile, viable female in a few (e.g., boas)). ZW offspring are produced by endoreplication before meiosis or by central fusion. ZZ and WW offspring occur either by terminal fusion or by endomitosis in the egg cell.
In polyploid obligate parthenogens like the whiptail lizard, all the offspring are female.
In many hymenopteran insects such as honeybees, female eggs are
produced sexually, using sperm from a drone father, while the production
of further drones (males) depends on the queen (and occasionally
workers) producing unfertilized eggs. This means that females (workers
and queens) are always diploid, while males (drones) are always haploid,
and produced parthenogenetically.
Facultative
Facultative parthenogenesis is the term for when a female can produce offspring either sexually or via asexual reproduction.
Facultative parthenogenesis is extremely rare in nature, with only a
few examples of animal taxa capable of facultative parthenogenesis. One of the best-known examples of taxa exhibiting facultative parthenogenesis are mayflies; presumably, this is the default reproductive mode of all species in this insect order.
Facultative parthenogenesis is believed to be a response to a lack of a
viable male. A female may undergo facultative parthenogenesis if a male
is absent from the habitat or if it is unable to produce viable
offspring.
Facultative parthenogenesis is often used to describe cases of spontaneous parthenogenesis in normally sexual animals. For example, many cases of spontaneous parthenogenesis in sharks, some snakes, Komodo dragons and a variety of domesticated birds were widely attributed to facultative parthenogenesis. These cases are examples of spontaneous parthenogenesis.
The occurrence of such asexually produced eggs in sexual animals can be
explained by a meiotic error, leading to eggs produced via automixis.
Obligate
Obligate parthenogenesis is the process in which organisms exclusively reproduce through asexual means.
Many species have been shown to transition to obligate parthenogenesis
over evolutionary time. Well documented transitions to obligate
parthenogenesis have been found in numerous metazoan taxa, albeit
through highly diverse mechanisms. These transitions often occur as a
result of inbreeding or mutation within large populations.
There are a number of documented species, specifically salamanders and
geckos, that rely on obligate parthenogenesis as their major method of
reproduction. As such, there are over 80 species of unisex reptiles
(mostly lizards but including a single snake species), amphibians and
fishes in nature for which males are no longer a part of the
reproductive process.
A female will produce an ovum with a full set (two sets of genes)
provided solely by the mother. Thus, a male is not needed to provide
sperm to fertilize the egg. This form of asexual reproduction is thought
in some cases to be a serious threat to biodiversity for the subsequent
lack of gene variation and potentially decreased fitness of the
offspring.
Some invertebrate species that feature (partial) sexual
reproduction in their native range are found to reproduce solely by
parthenogenesis in areas to which they have been introduced.
Relying solely on parthenogenetic reproduction has several advantages
for an invasive species: it obviates the need for individuals in a very
sparse initial population to search for mates, and an exclusively female
sex distribution allows a population to multiply and invade more
rapidly, potentially up to twice as fast. Examples include several aphid species and the willow sawfly, Nematus oligospilus, which is sexual in its native Holarctic habitat but parthenogenetic where it has been introduced into the Southern Hemisphere.
Natural occurrence
Parthenogenesis is seen to occur naturally in aphids, Daphnia, rotifers, nematodes and some other invertebrates, as well as in many plants. Among vertebrates, strict parthenogenesis is only known to occur in lizards, snakes, birds and sharks,
with fish, amphibians and reptiles exhibiting various forms of
gynogenesis and hybridogenesis (an incomplete form of parthenogenesis). The first all-female (unisexual) reproduction in vertebrates was described in the fish Poecilia formosa in 1932.
Since then at least 50 species of unisexual vertebrate have been
described, including at least 20 fish, 25 lizards, a single snake
species, frogs, and salamanders. Other usually sexual species may occasionally reproduce parthenogenetically; the Komodo dragon and hammerhead and blacktip sharks are recent additions to the known list of spontaneous parthenogenetic vertebrates. As with all types of asexual reproduction,
there are both costs (low genetic diversity and therefore
susceptibility to adverse mutations that might occur) and benefits
(reproduction without the need for a male) associated with
parthenogenesis.
Parthenogenesis is distinct from artificial animal cloning, a process where the new organism is necessarily genetically identical to the cell donor. In cloning, the nucleus of a diploid cell from a donor organism is inserted into an enucleated egg cell and the cell is then stimulated to undergo continued mitosis,
resulting in an organism that is genetically identical to the donor.
Parthenogenesis is different, in that it originates from the genetic
material contained within an egg cell and the new organism is not
necessarily genetically identical to the parent.
Parthenogenesis may be achieved through an artificial process as described below under the discussion of mammals.
Oomycetes
Apomixis can apparently occur in Phytophthora, an oomycete. Oospores
from an experimental cross were germinated, and some of the progeny
were genetically identical to one or other parent, implying that meiosis
did not occur and the oospores developed by parthenogenesis.
Velvet worms
No males of Epiperipatus imthurni have been found, and specimens from Trinidad were shown to reproduce parthenogenetically. This species is the only known velvet worm to reproduce via parthenogenesis.
Rotifers
In bdelloidrotifers, females reproduce exclusively by parthenogenesis (obligate parthenogenesis), while in monogonont
rotifers, females can alternate between sexual and asexual reproduction
(cyclical parthenogenesis). At least in one normally cyclical
parthenogenetic species obligate parthenogenesis can be inherited: a
recessive allele leads to loss of sexual reproduction in homozygous
offspring.
Flatworms
At least two species in the genus Dugesia, flatworms in the Turbellaria sub-division of the phylumPlatyhelminthes, include polyploid individuals that reproduce by parthenogenesis. This type of parthenogenesis requires mating, but the sperm does not contribute to the genetics of the offspring (the parthenogenesis is pseudogamous,
alternatively referred to as gynogenetic). A complex cycle of matings
between diploid sexual and polyploid parthenogenetic individuals
produces new parthenogenetic lines.
Parthenogenesis in insects can cover a wide range of mechanisms. The offspring produced by parthenogenesis may be of both sexes, only female (thelytoky, e.g. aphids and some hymenopterans) or only male (arrhenotoky, e.g. most hymenopterans). Both true parthenogenesis and pseudogamy (gynogenesis or sperm-dependent parthenogenesis) are known to occur.
The egg cells, depending on the species may be produced without meiosis
(apomictically) or by one of the several automictic mechanisms.
A related phenomenon, polyembryony is a process that produces
multiple clonal offspring from a single egg cell. This is known in some
hymenopteran parasitoids and in Strepsiptera.
In automictic species the offspring can be haploid or diploid.
Diploids are produced by doubling or fusion of gametes after meiosis.
Fusion is seen in the Phasmatodea, Hemiptera (Aleurodids and Coccidae), Diptera, and some Hymenoptera.
In addition to these forms is hermaphroditism, where both the eggs and sperm are produced by the same individual, but is not a type of parthenogenesis. This is seen in three species of Icerya scale insects.
Parasitic bacteria like Wolbachia have been noted to induce automictic thelytoky in many insect species with haplodiploid systems. They also cause gamete duplication in unfertilized eggs causing them to develop into female offspring.
Among species with the haplo-diploid sex-determination system, such as hymenopterans (ants, bees and wasps) and thysanopterans (thrips), haploid males
are produced from unfertilized eggs. Usually, eggs are laid only by the
queen, but the unmated workers may also lay haploid, male eggs either
regularly (e.g. stingless bees) or under special circumstances. An
example of non-viable parthenogenesis is common among domesticated honey bees.
The queen bee is the only fertile female in the hive; if she dies
without the possibility of a viable replacement queen, it is not
uncommon for the worker bees to lay eggs. This is a result of the lack
of the queen's pheromones and the pheromones secreted by uncapped brood,
which normally suppress ovarian development in workers. Worker bees are
unable to mate, and the unfertilized eggs produce only drones (males),
which can mate only with a queen. Thus, in a relatively short period,
all the worker bees die off, and the new drones follow if they have not
been able to mate before the collapse of the colony. This behavior is
believed to have evolved to allow a doomed colony to produce drones
which may mate with a virgin queen and thus preserve the colony's
genetic progeny.
A few ants and bees are capable of producing diploid female
offspring parthenogenetically. These include a honey bee subspecies from
South Africa, Apis mellifera capensis, where workers are capable of producing diploid
eggs parthenogenetically, and replacing the queen if she dies; other
examples include some species of small carpenter bee, (genus Ceratina). Many parasitic wasps are known to be parthenogenetic, sometimes due to infections by Wolbachia.
The workers in five ant species and the queens in some ants are known to reproduce by parthenogenesis. In Cataglyphis cursor, a European formicine ant, the queens and workers can produce new queens by parthenogenesis. The workers are produced sexually.
In Central and South American electric ants, Wasmannia auropunctata,
queens produce more queens through automictic parthenogenesis with
central fusion. Sterile workers usually are produced from eggs
fertilized by males. In some of the eggs fertilized by males, however,
the fertilization can cause the female genetic material to be ablated
from the zygote. In this way, males pass on only their genes to become
fertile male offspring. This is the first recognized example of an
animal species where both females and males can reproduce clonally
resulting in a complete separation of male and female gene pools.
As a consequence, the males will only have fathers and the queens only
mothers, while the sterile workers are the only ones with both parents
of both genders.
These ants get both the benefits of both asexual and sexual reproduction—the
daughters who can reproduce (the queens) have all of the mother's
genes, while the sterile workers whose physical strength and disease
resistance are important are produced sexually.
Other examples of insect parthenogenesis can be found in gall-forming aphids (e.g., Pemphigus betae), where females reproduce parthenogenetically during the gall-forming phase of their life cycle and in grass thrips. In the grass thrips genus Aptinothrips there have been, despite the very limited number of species in the genus, several transitions to asexuality.
Crustaceans
Crustacean reproduction varies both across and within species. The water fleaDaphnia pulex alternates between sexual and parthenogenetic reproduction. Among the better-known large decapodcrustaceans, some crayfish reproduce by parthenogenesis. "Marmorkrebs" are parthenogenetic crayfish that were discovered in the pet trade in the 1990s.
Offspring are genetically identical to the parent, indicating it
reproduces by apomixis, i.e. parthenogenesis in which the eggs did not
undergo meiosis. Spinycheek crayfish (Orconectes limosus) can reproduce both sexually and by parthenogenesis. The Louisiana red swamp crayfish (Procambarus clarkii), which normally reproduces sexually, has also been suggested to reproduce by parthenogenesis, although no individuals of this species have been reared this way in the lab. Artemia parthenogenetica is a species or series of populations of parthenogenetic brine shrimps.
Spiders
At least two species of spiders in the family Oonopidae (goblin spiders), Heteroonopsspinimanus and Triaeris stenaspis,
are thought to be parthenogenetic, as no males have ever been
collected. Parthenogenetic reproduction has been demonstrated in the
laboratory for T. stenaspis.
Sharks
Parthenogenesis in sharks has been confirmed in at least three species, the bonnethead, the blacktip shark, and the zebra shark, and reported in others.
A bonnethead, a type of small hammerhead shark, was found to have produced a pup, born live on December 14, 2001 at Henry Doorly Zoo
in Nebraska, in a tank containing three female hammerheads, but no
males. The pup was thought to have been conceived through
parthenogenesis. The shark pup was apparently killed by a stingray within days of birth.
The investigation of the birth was conducted by the research team from
Queen's University Belfast, Southeastern University in Florida, and
Henry Doorly Zoo itself, and it was concluded after DNA testing that the
reproduction was parthenogenetic. The testing showed the female pup's
DNA matched only one female who lived in the tank, and that no male DNA
was present in the pup. The pup was not a twin or clone of her mother,
but rather, contained only half of her mother's DNA ("automictic parthenogenesis").
This type of reproduction had been seen before in bony fish, but never
in cartilaginous fish such as sharks, until this documentation.
In the same year, a female Atlantic blacktip shark in Virginia reproduced via parthenogenesis.
On October 10, 2008 scientists confirmed the second case of a "virgin
birth" in a shark. The Journal of Fish Biology reported a study in which
scientists said DNA testing proved that a pup carried by a female
Atlantic blacktip shark in the Virginia Aquarium & Marine Science
Center contained no genetic material from a male.
In 2002, two white-spotted bamboo sharks were born at the Belle Isle Aquarium
in Detroit. They hatched 15 weeks after being laid. The births baffled
experts as the mother shared an aquarium with only one other shark,
which was female. The female bamboo sharks had laid eggs in the past.
This is not unexpected, as many animals will lay eggs even if there is
not a male to fertilize them. Normally, the eggs are assumed to be
inviable and are discarded. This batch of eggs was left undisturbed by
the curator as he had heard about the previous birth in 2001 in Nebraska
and wanted to observe whether they would hatch. Other possibilities had
been considered for the birth of the Detroit bamboo sharks including
thoughts that the sharks had been fertilized by a male and stored the
sperm for a period of time, as well as the possibility that the Belle
Isle bamboo shark is a hermaphrodite, harboring both male and female sex
organs, and capable of fertilizing its own eggs, but that is not
confirmed.
In 2008, a Hungarian aquarium had another case of parthenogenesis
after its lone female shark produced a pup without ever having come
into contact with a male shark.
The repercussions of parthenogenesis in sharks, which fails to
increase the genetic diversity of the offspring, is a matter of concern
for shark experts, taking into consideration conservation management
strategies for this species, particularly in areas where there may be a
shortage of males due to fishing or environmental pressures. Although
parthenogenesis may help females who cannot find mates, it does reduce
genetic diversity.
In 2011, recurring shark parthenogenesis over several years was demonstrated in a captive zebra shark, a type of carpet shark. DNA genotyping demonstrated that individual zebra sharks can switch from sexual to parthenogenetic reproduction.
In 2012, facultative parthenogenesis was reported in wild
vertebrates for the first time by US researchers amongst captured
pregnant copperhead and cottonmouth female pit-vipers. The Komodo dragon, which normally reproduces sexually, has also been found able to reproduce asexually by parthenogenesis. A case has been documented of a Komodo dragon reproducing via sexual reproduction after a known parthenogenetic event, highlighting that these cases of parthenogenesis are reproductive accidents, rather than adaptive, facultative parthenogenesis.
Some reptile species use a ZW chromosome system, which produces
either males (ZZ) or females (ZW). Until 2010, it was thought that the
ZW chromosome system used by reptiles was incapable of producing viable
WW offspring, but a (ZW) female boa constrictor was discovered to have
produced viable female offspring with WW chromosomes.
Parthenogenesis has been studied extensively in the New Mexico whiptail in the genus Aspidoscelis
of which 15 species reproduce exclusively by parthenogenesis. These
lizards live in the dry and sometimes harsh climate of the southwestern
United States and northern Mexico. All these asexual species appear to
have arisen through the hybridization of two or three of the sexual
species in the genus leading to polyploid
individuals. The mechanism by which the mixing of chromosomes from two
or three species can lead to parthenogenetic reproduction is unknown.
Recently, a hybrid parthenogenetic whiptail lizard was bred in the
laboratory from a cross between an asexual and a sexual whiptail.
Because multiple hybridization events can occur, individual
parthenogenetic whiptail species can consist of multiple independent
asexual lineages. Within lineages, there is very little genetic
diversity, but different lineages may have quite different genotypes.
An interesting aspect to reproduction in these asexual lizards is
that mating behaviors are still seen, although the populations are all
female. One female plays the role played by the male in closely related
species, and mounts the female that is about to lay eggs. This behaviour
is due to the hormonal cycles of the females, which cause them to
behave like males shortly after laying eggs, when levels of progesterone
are high, and to take the female role in mating before laying eggs,
when estrogen dominates. Lizards who act out the courtship ritual have
greater fecundity
than those kept in isolation, due to the increase in hormones that
accompanies the mounting. So, although the populations lack males, they
still require sexual behavioral stimuli for maximum reproductive success.
Some lizard parthenogens show a pattern of geographic
parthenogenesis, occupying high mountain areas where their ancestral
forms have an inferior competition ability. In Caucasian rock lizards of genus Darevskia, which have six parthenogenetic forms of hybrid origin hybrid parthenogenetic form D. "dahli" has a broader niche than either of its bisexual ancestors and its expansion throughout the Central Lesser Caucasus caused decline of the ranges of both its maternal and paternal species.
Birds
Parthenogenesis in birds is known mainly from studies of domesticated turkeys and chickens, although it has also been noted in the domestic pigeon. In most cases the egg fails to develop normally or completely to hatching. The first description of parthenogenetic development in a passerine was demonstrated in captive zebra finches, although the dividing cells exhibited irregular nuclei and the eggs did not hatch.
Parthenogenesis in turkeys appears to result from a conversion of haploid cells to diploid;
most embryos produced in this way die early in development. Rarely,
viable birds result from this process, and the rate at which this occurs
in turkeys can be increased by selective breeding, however male turkeys produced from parthenogenesis exhibit smaller testes and reduced fertility.
In 2021, the San Diego Zoo reported that they had two unfertilized eggs from their California condor
breeding program hatch. This is the first known example of
parthenogenesis in this species, as well as one of the only known
examples of parthenogenesis happening where males are still present.
Mammals
There
are no known cases of naturally occurring mammalian parthenogenesis in
the wild. Though claims of that happening date back to antiquity,
including in humans (for example, Virgin Mary, mother of Jesus),
this has never been observed in a controlled environment.
Parthenogenetic progeny of mammals would have two X chromosomes, and
would therefore be genetically female.
In April 2004, scientists at Tokyo University of Agriculture used parthenogenesis successfully to create a fatherless mouse. Using gene targeting, they were able to manipulate two imprinted loci H19/IGF2 and DLK1/MEG3 to produce bi-maternal mice at high frequency and subsequently show that fatherless mice have enhanced longevity.
Induced parthenogenesis in mice and monkeys often results in abnormal development. This is because mammals have imprinted
genetic regions, where either the maternal or the paternal chromosome
is inactivated in the offspring in order for development to proceed
normally. A mammal created by parthenogenesis would have double doses of
maternally imprinted genes and lack paternally imprinted genes, leading
to developmental abnormalities. It has been suggested that defects in placental folding or interdigitation are one cause of swine parthenote abortive development. As a consequence, research on human parthenogenesis is focused on the production of embryonic stem cells for use in medical treatment, not as a reproductive strategy.
Use of an electrical or chemical stimulus can produce the beginning
of the process of parthenogenesis in the asexual development of viable
offspring.
Induction of parthenogenesis in swine. Parthenogenetic development of swine oocytes.
High metaphase promoting factor (MPF) activity causes mammalian oocytes
to arrest at the metaphase II stage until fertilization by a sperm. The
fertilization event causes intracellular calcium oscillations, and
targeted degradation of cyclin B, a regulatory subunit of MPF, thus
permitting the MII-arrested oocyte to proceed through meiosis. To
initiate parthenogenesis of swine oocytes, various methods exist to
induce an artificial activation that mimics sperm entry, such as calcium
ionophore treatment, microinjection of calcium ions, or electrical
stimulation. Treatment with cycloheximide, a non-specific protein
synthesis inhibitor, enhances parthenote development in swine presumably
by continual inhibition of MPF/cyclin B.
As meiosis proceeds, extrusion of the second polar is blocked by
exposure to cytochalasin B. This treatment results in a diploid (2
maternal genomes) parthenote. Parthenotes can be surgically transferred
to a recipient oviduct for further development, but will succumb by
developmental failure after ≈30 days of gestation. The swine parthenote
placentae often appears hypo-vascular and is approximately 50% smaller
than biparental offspring placentae: see free image (Figure 1) in linked
reference.
During oocyte development, high metaphase promoting factor (MPF)
activity causes mammalian oocytes to arrest at the metaphase II stage
until fertilization by a sperm. The fertilization event causes
intracellular calcium oscillations, and targeted degradation of cyclin
B, a regulatory subunit of MPF, thus permitting the MII-arrested oocyte
to proceed through meiosis.
To initiate parthenogenesis of swine oocytes, various methods
exist to induce an artificial activation that mimics sperm entry, such
as calcium ionophore treatment, microinjection of calcium ions, or
electrical stimulation. Treatment with cycloheximide, a non-specific
protein synthesis inhibitor, enhances parthenote development in swine
presumably by continual inhibition of MPF/cyclin B.
As meiosis proceeds, extrusion of the second polar is blocked by
exposure to cytochalasin B. This treatment results in a diploid (2
maternal genomes) parthenote
Parthenotes can be surgically transferred to a recipient oviduct for
further development, but will succumb to developmental failure after ≈30
days of gestation. The swine parthenote placentae often appears
hypo-vascular: see free image (Figure 1) in linked reference.
Humans
Reports
of human parthenogenesis have famously existed since ancient times,
featuring prominently in Christianity and various other religions. More
recently, Helen Spurway, a geneticist specializing in the reproductive biology of the guppy, Lebistes reticulatus,
claimed, in 1955, that parthenogenesis, which occurs in the guppy in
nature, may also occur (though very rarely) in the human species,
leading to so-called "virgin births". This created some sensation among
her colleagues and the lay public alike.
Sometimes an embryo may begin to divide without fertilisation but it
cannot fully develop on its own, so while it may create some skin and
nerve cells, it cannot create others (such as skeletal muscle) and
becomes a type of benign tumor called an ovarian teratoma.
Spontaneous ovarian activation is not rare and has been known about
since the 19th century. Some teratomas can even become primitive fetuses
(fetiform teratoma) with imperfect heads, limbs and other structures
but these are non-viable. However, in 1995 there was a reported case of
partial-parthenogenesis; a boy was found to have some of his cells (such
as white blood cells) to be lacking in any genetic content from his
father. Scientists believe that in the boy's case, an unfertilised egg
began to self-divide but then had some (but not all) of its cells
fertilised by a sperm cell; this must have happened early in
development, as self-activated eggs quickly lose their ability to be
fertilised. The unfertilised cells eventually duplicated their DNA,
boosting their chromosomes to 46. When the unfertilised cells hit a
developmental block, the fertilised cells took over and developed that
tissue. The boy had asymmetrical facial features and learning
difficulties but was otherwise healthy. This would make him a
parthenogenetic chimera (a child with two cell lineages in his body).
While over a dozen similar cases have been reported since then (usually
discovered after the patient demonstrated clinical abnormalities),
there have been no scientifically confirmed reports of a non-chimeric,
clinically healthy human parthenote (i.e. produced from a single,
parthenogenetic-activated oocyte).
On June 26, 2007, International Stem Cell Corporation (ISCC), a
California-based stem cell research company, announced that their lead
scientist, Dr. Elena Revazova, and her research team were the first to
intentionally create human stem cells from unfertilized human eggs using
parthenogenesis. The process may offer a way for creating stem cells
that are genetically matched to a particular female for the treatment of
degenerative diseases that might affect her. In December 2007, Dr.
Revazova and ISCC published an article illustrating a breakthrough in the use of parthenogenesis to produce human stem cells that are homozygous in the HLA region of DNA.
These stem cells are called HLA homozygous parthenogenetic human stem
cells (hpSC-Hhom) and have unique characteristics that would allow
derivatives of these cells to be implanted into millions of people
without immune rejection. With proper selection of oocyte donors according to HLA haplotype, it is possible to generate a bank of cell lines whose tissue derivatives, collectively, could be MHC-matched with a significant number of individuals within the human population.
On August 2, 2007, after an independent investigation, it was revealed that discredited South Korean scientist Hwang Woo-Suk
unknowingly produced the first human embryos resulting from
parthenogenesis. Initially, Hwang claimed he and his team had extracted
stem cells from cloned human embryos, a result later found to be
fabricated. Further examination of the chromosomes of these cells show
indicators of parthenogenesis in those extracted stem cells, similar to
those found in the mice
created by Tokyo scientists in 2004. Although Hwang deceived the world
about being the first to create artificially cloned human embryos, he
did contribute a major breakthrough to stem cell research by creating
human embryos using parthenogenesis.
The truth was discovered in 2007, long after the embryos were created
by him and his team in February 2004. This made Hwang the first,
unknowingly, to successfully perform the process of parthenogenesis to
create a human embryo and, ultimately, a human parthenogenetic stem cell
line.
A form of asexual reproduction related to parthenogenesis is
gynogenesis. Here, offspring are produced by the same mechanism as in
parthenogenesis, but with the requirement that the egg merely be
stimulated by the presence of sperm
in order to develop. However, the sperm cell does not contribute any
genetic material to the offspring. Since gynogenetic species are all
female, activation of their eggs requires mating with males of a closely
related species for the needed stimulus. Some salamanders of the genus Ambystoma are gynogenetic and appear to have been so for over a million years. It is believed
that the success of those salamanders may be due to rare fertilization
of eggs by males, introducing new material to the gene pool, which may
result from perhaps only one mating out of a million. In addition, the amazon molly is known to reproduce by gynogenesis.
Hybridogenesis is a mode of reproduction of hybrids. Hybridogenetic hybrids (for example AB genome), usually females, during gametogenesis exclude one of parental genomes (A) and produce gametes with unrecombinedgenome of second parental species (B), instead of containing mixed recombined parental genomes. First genome (A) is restored by fertilization of these gametes with gametes from the first species (AA, sexual host, usually male).
So hybridogenesis is not completely asexual, but instead hemiclonal: half of genome is passed to the next generation clonally, unrecombined, intact (B), other half sexually, recombined (A).
This process continues, so that each generation is half (or
hemi-) clonal on the mother's side and has half new genetic material
from the father's side.
This form of reproduction is seen in some live-bearing fish of the genus Poeciliopsis as well as in some of the Pelophylax spp. ("green frogs" or "waterfrogs"):
Example crosses between pool frog (Pelophylax lessonae), marsh frog (P. ridibundus) and their hybrid – edible frog (P. kl. esculentus). First one is the primary hybridisation generating hybrid, second one is most widespread type of hybridogenesis.
Other examples where hybridogenesis is at least one of modes of reproduction include i.e.
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