Nothing Special   »   [go: up one dir, main page]

Jump to content

Hermaphrodite: Difference between revisions

From Wikipedia, the free encyclopedia
Content deleted Content added
NigelR (talk | contribs)
m rvv
No edit summary
Line 38: Line 38:
*[[Supernumerary body part]]
*[[Supernumerary body part]]
*[[The World (Tarot card)]]
*[[The World (Tarot card)]]
*[[Rosie O'Donnell]]


== References ==
== References ==

Revision as of 23:44, 5 September 2006

For the Julia Ward Howe novel, see The Hermaphrodite.
For hermaphroditism in humans, see Intersexuality.
For the type of electrical connector, see Gender of connectors and fasteners.
The 1st-century BC sculpture 'The Reclining Hermaphrodite', in the Museo Palazzo Massimo Alle Terme in Rome

In zoology and botany, a hermaphrodite is an organism that possesses both male and female sex organs during its life[1]. In many species, hermaphroditism is a common part of the life-cycle. Generally, hermaphroditism occurs in the invertebrates, although it occurs in a fair number of fish, and to a lesser degree in other vertebrates.

The term "hermaphrodite" has historically been used to describe people with ambiguous genitalia or biological sex. The broader term intersexual is often used and is preferred by many such individuals and medical professionals.[citation needed] However, some hermaphrodites do not like the sexual connotations and misunderstanding of the word "Intersexed" and thus prefer to use hermaphrodite instead.[citation needed] The term is still used by the pornography industry[citation needed], though often as a synonym for transsexual, as true human intersexuals are rare.

In animals

Sequential hermaphrodites

Sequential hermaphrodites are organisms born as one sex which later change into the other sex.

  • Protandry: When the organism starts as a male, and changes sex to a female later in life.
    • Example: The seabasses (Family Serranidae). These are a highly sought food fish complex made up of primarily groupers. Since even a small male can produce more than enough sperm to fertilize a huge number of eggs, while a female's egg output increases greatly with an increase in size, this strategy makes sense for an organism (fish in general) where over 90% of the eggs laid will not result in a fish that reaches sexual maturity. It has been shown that fishing pressure actually is causing a change in when the switch from male to female occurs, since fishermen naturally prefer to catch the larger fish. The populations are generally changing sex at a smaller size, due to artificial selection.
  • Protogyny: When the organism starts as a female, and changes sex to a male later in life.
    • Example: Wrasses (Family Labridae) are reef fish that tend to have three distinct sexual types. Small females, immature males and supermales. The small females and the immature males have identical colorations. The supermale is usually brightly colored, and there is only one in a given area of the reef. This supermale dominates the other wrasses of the species, having the choice of females to mate with. When the supermale dies, the largest wrasse in the area, male or female, becomes the new supermale.

Simultaneous hermaphrodites

A simultaneous hermaphrodite (or synchronous hermaphrodite) is an organism that has both male and female sexual organs at the same time as an adult. Usually, self-fertilization does not occur.

  • Example: Hamlets, unlike other fish, seem quite at ease mating in front of divers, allowing observations in the wild to occur readily. They do not practice self-fertilization, but when they find a mate, the pair takes turns between which one acts as the male and which acts as the female through multiple matings, usually over the course of several nights.

Gonadal dysgenesis

Gonadal dysgenesis is a type of intersexuality formerly known as "True Hermaphroditism", occurs in about one percent of mammals (including humans), but it is extremely rare for both sets of sexual organs to be functional; usually neither set is functional. In many cases, these manifestations are altered, sometimes only cosmetically, to resemble standard male or female anatomy shortly after birth.

Fetal hermaphroditism in humans

Sigmund Freud (based on work by his associate Wilhelm Fliess) held fetal hermaphroditsm 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 bisexuality on that assumption. This was later revealed to be untrue (see sexual differentiation).

In plants

Hermaphrodite is used in botany to describe a flower that has both staminate (male, pollen-producing) and carpelate (female, seed-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 unisexual 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).

Etymology

The term "hermaphrodite" derives from Hermaphroditus, the son of Hermes and Aphrodite in Greek mythology, who was fused with a nymph, resulting in one possessing physical traits of both sexes. Thus Hermaphroditus was, by the modern terminology, a simultaneous hermaphrodite. The mythological figure of Tiresias, who figures in the Oedipus cycle as well as the Odyssey, was a sequential hermaphrodite, having been changed from a man to a woman and back by the gods.

See also

References

Further reading

  • M.M. Grumbach, and F.A. Conte. 1998. "Disorders of sex differentiation." in Williams Textbook of Endocrinology, eds. J.D. Wilson, D.W. Foster, H.M. Kronenberg, and P.R. Larsen, (Philadelphia: W B Saunders:1303-1425).
  • Molnar, Sebastian. 2004. Plant Reproductive Systems, internet version posted February 17, 2004.