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Hermaphrodite
A hermaphrodite is an organism that posses both male and female genitalia.[1] In many species, hermaphroditism is a common part of the life-cycle, particularly in some asexual animals and some plants. Hermaphroditism is sometimes considered sexual reproduction, not asexual reproduction. Generally, hermaphroditism occurs in the invertebrates, although it occurs in a fair number of fish, and to a lesser degree in other vertebrates. Historically, the term hermaphrodite has also been used to describe ambiguous genitalia and gonadal mosaicism in individuals of unisexual species, especially human beings. Recently, intersex has been used and preferred by many such individuals, encouraging medical professionals to use the term.[2] However, others with the condition do not like the connotations and misunderstanding of the word "intersexed" and thus prefer to use hermaphrodite instead.[citation needed] Additional recommended knowledge
In humansHermaphrodite was used to describe any person incompatible with the biological gender binary, but has recently been replaced by intersexual in medicine. Humans with typical reproductive organs but atypical clitoris/penis are called pseudohermaphrodites in medical literature. Whether hermaphroditism is a disorder or merely an unusual condition is a matter of opinion. In most societies, the common assumption is that all people are, or at least should be, either male or female.[citation needed] This assumption can make life difficult for hermaphrodites. People with intersex conditions sometimes choose to live exclusively as one sex or the other, using clothing, social cues, genital surgery, and hormone replacement therapy to blend into the sex they identify with more closely. Some people who are intersexed, such as some of those with Klinefelter's syndrome and androgen insensitivity syndrome, outwardly appear completely female or male already, without realizing they are intersexed. Other kinds of intersex conditions are identified immediately at birth because those with the condition have a sexual organ larger than a clitoris and smaller than a penis. Intersexuality is caused by unusual sex hormones; the unusual hormones may be caused by an atypical set of sex chromosomes. Fetal hermaphroditism in humansSigmund Freud (based on work by his associate Wilhelm Fliess) held fetal hermaphroditism to be a fact of the physiological development of humans. He was so certain of this, in fact, that he based much of his theory of innate sexuality on that assumption. Similarly, in contemporary times, fetuses before sexual differentiation are sometimes described as female by doctors explaining the process.[3] Neither concept is technically true. Before this stage, humans are simply undifferentiated and possess a Müllerian duct, a Wolffian duct, and a genital tubercle, although all males among placental and marsupial mammals (except mice, and horses) retain the female structure of nipples. In animalsSequential hermaphroditesSequential hermaphrodites (dichogamy) are organisms born as one sex and then later change into the other sex, and can only function as one sex at one time. A few species in this group can change gender multiple times, but they can only function as one sex at a time. Unlike humans, these animals' DNA does not determine their gender, allowing full functional gender change without modifying the DNA.
The order of sequential hermaphroditism within a species is often driven by resource demands. In a population where resources are scarce and can support limited bearing of young, it is advantageous to have a larger population of males supporting one female. One would expect that a species that typically faces this scenario (such as many clownfish living in a single anemone) would have organisms that start as male, and perhaps one individual per group would have changed to be female at any given time. Where resources are abundant and can support bearing of many young, on the other hand, it is advantageous to have many females mating with a limited number of males, so that more young are produced. One would expect that a species that typically faces this scenario (such as parrotfish that can forage over large distances) would have individuals that start as female, and perhaps one individual per group would have changed to be male at any given time. Simultaneous hermaphroditesA simultaneous hermaphrodite (or synchronous hermaphrodite) is an adult organism that has both male and female sexual organs at the same time. Usually, self-fertilization does not occur.
Other interpretations of hermaphroditismSome female children are born with an enlarged clitoris, often through their mother's exposure to drugs, chemicals, or hormones during the pregnancy. Since the clitoris is the structure that differentiates into the penis in males, its enlargement may be misinterpreted as a penis if the enlargement is significant. Hyenas have a clitoris that is greatly enlarged, so much so, that they were described as hermaphrodites -- not only by the ancient Greeks, but as recently as among circus animal handlers in the twentieth century -- until scientific information was provided that clarified the misunderstanding. In plantsHermaphrodite is used in botany to describe a flower that has both staminate (male, pollen-producing) and carpelate (female, ovule-producing) parts that are self fertile or self pollenizing. Hermaphrodism in plants is more complex than in animals because plants can have hermaphroditic flowers as described, or bisexual flowers with both male and female types developing on the same individual—a closer analogy to animal hermaphrodism. However, this latter condition constitutes monoecy in plants, and is especially common to the conifers, while occurring in only about 7% of angiosperm species (Molnar, 2004).
EtymologyThe term "hermaphrodite" derives from Hermaphroditus, the son of Hermes and Aphrodite in Greek mythology, who was fused with a nymph, Salmacis, resulting in one individual possessing physical traits of both genders. Thus Hermaphroditus could be called, using modern terminology, a simultaneous hermaphrodite. The mythological figure of Tiresias, who figures in the Oedipus cycle as well as the Odyssey, could be called a sequential hermaphrodite, having been changed from a man to a woman and back by the gods. See also
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This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Hermaphrodite". A list of authors is available in Wikipedia. |