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Meat Eater ant colony swarming

Fire ants

Eusociality is the phenomenon of reproductive specialization found in some animals. It generally involves the breeding of sterile members of the species, which carry out specialized tasks, effectively caring for the reproductive members. Image File history File links Size of this preview: 800 × 534 pixelsFull resolution (1600 × 1067 pixel, file size: 676 KB, MIME type: image/jpeg) Meat eater ant nest swarming. ... Image File history File links Size of this preview: 800 × 534 pixelsFull resolution (1600 × 1067 pixel, file size: 676 KB, MIME type: image/jpeg) Meat eater ant nest swarming. ... Download high resolution version (640x873, 126 KB)Photograph of fire ants. ... Download high resolution version (640x873, 126 KB)Photograph of fire ants. ...

Eusociality with biologically sterile individuals represents the most extreme form of kin altruism. The analysis of eusociality played a key role in the development of theories in sociobiology. Kin selection was first suggested by Darwin as an explanation of the sterile castes of social insects and has later been mathematically defined by W. D. Hamilton as a mechanism for the evolution of apparently altruistic acts. ... Sociobiology is a synthesis of scientific disciplines that explains behaviour in all species by considering the evolutionary advantages of social behaviours. ...

The most familiar examples are insects such as ants, bees, and wasps (the order Hymenoptera), as well as termites (order Isoptera), all with reproductive queens and sterile workers. Subfamilies Aenictogitoninae Agroecomyrmecinae Amblyoponinae (incl. ... Families Andrenidae Apidae Colletidae Halictidae Megachilidae Melittidae Stenotritidae Bees are flying insects, closely related to wasps and ants. ... Suborder Apocrita See text for explanation. ... Suborders Apocrita Symphyta Many families, see article Hymenoptera is one of the larger orders of Insects, comprising the sawflies, wasps, bees, and ants. ... Families Mastotermitidae Kalotermitidae Termopsidae Hodotermitidae Rhinotermitidae Serritermitidae Termitidae Termites, sometimes known as white ants, are a group of eusocial insects usually classified at the taxonomic rank of order, Isoptera. ... Infertility is the inability to naturally conceive a child or to carry a pregnancy to full term. ...

Evolution of eusocial behavior

There are two causes of eusociality: kin-selected altruism and high inbreeding. In evolutionary biology, kin selection refers to changes in gene frequency across generations that are driven at least in part by interactions between related individuals, and this forms much of the conceptual basis of the theory of social evolution. ... Inbreeding is breeding between close relatives, whether plant or animal. ...

Its defining features are:

1. reproductive division of labor
2. overlap of generations
3. cooperative care of young
4. sterile castes (not always present)

In spite of the obvious advantages of common foraging and defense, eusocial animals present a seeming paradox, which troubled Darwin: if adaptive evolution unfolds by differential survival of successful species, how can a species succeed in which most individuals don't breed at all? How can individuals incapable of passing on their genes possibly evolve and persist? Since they do not breed, their fitness should be zero and any alleles causing this condition should be eliminated from the population immediately. In Origin of Species, Darwin called this altruistic behavior the "one special difficulty, which at first appeared to me insuperable, and actually fatal to my theory." Darwin anticipated that the resolution to the paradox would lie in the close family relationship, but the complete answer (kin selection or inclusive fitness) had to wait for the discovery of the mechanisms for genetic inheritance. Foraging just means looking for food (or, metaphorically, anything else). ... For other people of the same surname, and places and things named after Charles Darwin, see Darwin. ... A biological adaptation is an anatomical structure, physiological process or behavioral trait of an organism that has evolved over a period of time by the process of natural selection such that it increases the expected long-term reproductive success of the organism. ... The 1859 edition of On the Origin of Species First published in 1859, The Origin of Species (full title On the Origin of Species by Means of Natural Selection, or the Preservation of Favoured Races in the Struggle for Life) by British naturalist Charles Darwin is one of the pivotal...

Eusociality may be easier for species like ants to evolve, due to their haplodiploidy, which increases the significance of kin selection. Sisters are more related to each other than to their offspring. This mechanism of sex determination gives rise to what W. D. Hamilton first termed "supersisters" who share 75 per cent of their genes on average. Sterile workers are more closely related to their supersisters than to any offspring they might have, if they were to breed themselves. From the "selfish gene's" point-of-view, it is advantageous to raise more sisters. Even though workers cannot reproduce, they are passing on more of their genes by caring for their sisters than they would by having their own offspring (which would only have 50% of their genes). This unusual situation where females have greater fitness when they are sterile has led to the independent evolution of eusociality occurring 11 separate times within the haplodiploid group Hymenoptera - ants, bees and wasps. However, Hymenoptera is a large group and the majority of Hymenopterans are not social. Furthermore, highly developed eusociality also exists in non-hymenopterans, perhaps most prominently in termites. Certain vertebrates (such as the naked mole rat) have also been described as eusocial. Ploidy is the number of homologous sets of chromosomes in a biological cell. ... In evolutionary biology, kin selection refers to changes in gene frequency across generations that are driven at least in part by interactions between related individuals, and this forms much of the conceptual basis of the theory of social evolution. ... W. D. Hamilton William Donald Bill Hamilton, F.R.S. (1 August 1936 — 7 March 2000) was a British evolutionary biologist, considered one of the greatest evolutionary theorists of the 20th century. ... The Selfish Gene is a controversial book by Richard Dawkins published in 1976. ... Wikipedia does not yet have an article with this exact name. ... Families Andrenidae Anthophoridae Apidae Colletidae Ctenoplectridae Halictidae Heterogynaidae Megachilidae Melittidae Oxaeidae Sphecidae Stenotritidae This article is about the insect. ... Families See text. ... Families Mastotermitidae Kalotermitidae Termopsidae Hodotermitidae Rhinotermitidae Serritermitidae Termitidae Reference: Earthlife as of 2002-07-26 A termite (also known as a white ant) is any member of the order Isoptera, a group of social insects that eat wood and other cellulose-rich vegetable matter. ... Binomial name Heterocephalus glaber Rüppell, 1842 The Naked Mole Rat (Heterocephalus glaber), also known as the Sand Puppy, or Desert Mole Rat, is a burrowing rodent native to parts of East Africa. ...

Superorganism theory explains the evolutionary stability of eusociality by dictating that only reproductive individuals are counted as individuals and sterile individuals are simply independent parts of their reproductive parent. This theory makes sense only when the sterile caste is physically sterile and not simply being repressed. In this way the sterile caste provide for their reproductive parents so that their genes can spread through them. In essence, an animal's own red blood cells can be seen as sterile eusocial members of an animal's body colony. A group of organisms, such as an insect colony, that functions as a social unit. ...

Indeed, multicellular life seems to have essentially started out as colonies of one-celled creatures, in which most of the one-celled creatures became specialized to other roles in the colony, losing the ability to reproduce. Thus came the transition from hordes of cooperating one-celled animals (algae are an example) to colonies of one-celled organisms acting as single, permanent units (slime moulds), to the simplest multicellular life (sponges), from whence all higher animals evolved. A seaweed (Laurencia) up close: the branches are multicellular and only about 1 mm thick. ... Typical orders Protostelia    Protosteliida Myxogastria    Liceida    Echinosteliida    Trichiida    Stemonitida    Physarida Dictyostelia    Dictyosteliida Slime moulds are peculiar protists that normally take the form of amoebae, but under certain conditions develop fruiting bodies that release spores, superficially similar to the sporangia of fungi. ... Classes Calcarea Hexactinellida Demospongiae The sponges or poriferans (from Latin porus pore and ferre to bear) are animals of the phylum Porifera. ...

Other examples

Another widespread insect group exhibiting eusociality is the termites (order Isoptera), which in contrast to the Hymenoptera exhibit diploidy. Termites are most closely related to cockroaches and mantids, and are not closely related to the Hymenoptera. The strategy of eusociality arose once in an ancestral termite, whilst it arose several times in the hymenoptera. Families Mastotermitidae Kalotermitidae Termopsidae Hodotermitidae Rhinotermitidae Serritermitidae Termitidae Termites, sometimes known as white ants, are a group of eusocial insects usually classified at the taxonomic rank of order, Isoptera. ... Families Mastotermitidae Kalotermitidae Termopsidae Hodotermitidae Rhinotermitidae Serritermitidae Termitidae Reference: Earthlife as of 2002-07-26 A termite (also known as a white ant) is any member of the order Isoptera, a group of social insects that eat wood and other cellulose-rich vegetable matter. ... Diploid (meaning double in Greek) cells have two copies (homologs) of each chromosome (both sex- and non-sex determining chromosomes), usually one from the mother and one from the father. ...

Recently, some species of aphids (Order Hemiptera) were found to be eusocial, with many separate origins of the state. This is easily explicable due to their partially asexual mode of reproduction (sterile soldier castes being of the same clone as the reproducing female); most aphids that are related at all are members of the same clone. Families There are 10 families: Adelgidae - adelgids, conifer aphids, Adelges cooleyi, Hemlock Wolly Adelgid, Adelges piceae Anoeciidae Aphididae Drepanosiphidae Homomasagymibutae Greenideidae Hormaphididae Lachnidae Mindaridae Pemphigidae Phloeomyzidae Phylloxeridae Thelaxidae Aphids, also known as greenfly, blackfly or plant lice, are minute plant-feeding insects in the superfamily Aphidoidea in the homopterous division... Suborders Archaeorrhyncha Clypeorrhyncha Prosorrhyncha Sternorrhyncha Hemiptera is a large, cosmopolitan order of insects, comprising some 67,500 known species in three suborders. ... It has been suggested that Parthenogenesis be merged into this article or section. ...

Eusociality has arisen among some crustaceans and other arthropods. On some tropical reefs, several species of minute Synalpheus pistol shrimp that depend on certain sponges for the survival of their colony, live eusocially, with a single breeding female and a preponderance of male defenders, armed with outsize snapping claws. Classes & Subclasses Branchiopoda Phyllopoda Sarsostraca Remipedia Cephalocarida Maxillopoda Thecostraca Tantulocarida Branchiura Pentastomida Mystacocarida Copepoda Ostracoda Myodocopa Podocopa Malacostraca Phyllocarida Hoplocarida Eumalacostraca The nauplius larva of a dendrobranchiate Porcellio scaber, the common rough woodlouse, a terrestrial crustacean Pollicipes polymerus, the gooseneck barnacle Glyphea pseudastacus, a fossil glypheoid The crustaceans (Crustacea) are... Subphyla and Classes Subphylum Trilobitomorpha Trilobita - trilobites (extinct) Subphylum Chelicerata Arachnida - spiders,scorpions, etc. ... Binomial name Alpheus bellulus , Tiger pistol shrimp (Alpheus bellulus) is a type of shrimp, also called Symbiosis Shrimp, or Snapping Shrimp. ...

Eusociality is also known, in rare cases, among mammals: the naked mole rat is a clear case, and, less rigorously some canids can be argued to be eusocial, since usually only the alpha male and female will breed. In this case, the other members of the pack are not sterile, but suppress breeding in favour of the dominant pair. Subclasses Subclass Allotheria* Order Docodonta (extinct) Order Multituberculata (extinct) Order Palaeoryctoides (extinct) Order Triconodonta (extinct) Order Volaticotheria (extinct) Subclass Prototheria Order Monotremata Subclass Theria Infraclass Trituberculata (extinct) Infraclass Metatheria Infraclass Eutheria The mammals are the class of vertebrate animals characterized by the production of milk in females for the nourishment... Binomial name Heterocephalus glaber Rüppell, 1842 The Naked Mole Rat (Heterocephalus glaber), also known as the Sand Puppy, or Desert Mole Rat, is a burrowing rodent native to parts of East Africa. ... Genera Alopex Atelocynus Canis Cerdocyon Chrysocyon Cuon Dusicyon Fennecus Lycalopex Lycaon Nyctereutes Otocyon Pseudalopex Speothos Urocyon Vulpes Canidae is the family of carnivorous and omnivorous mammals commonly known as canines. ... An alpha male or alpha female is the individual in the community to whom the others follow and defer. ...

Fictional examples

• The idea of a human eusocial group was investigated in-depth in Stephen Baxter's novel Coalescent.

• The xenomorphs featured in the Alien movies have a eusocial hierarchy, with the Alien Queen breeding the other types.

• The Nac Mac Feegle in Terry Pratchett's Discworld series possess a eusocial culture, with hundreds of brothers led by a single mother, or "Kelda".

• Many of the races on Oddworld, including Mudokons, Glukkons, and Sligs, are eusocial.

• The Zerg of StarCraft are eusocial.

• The spiders in the film Arachnophobia are eusocial.

• The Majat of C. J. Cherryh's Serpent's Reach, set in her Alliance-Union universe, are eusocial.

• The Borg, a race of cybernetic organisms set in the Star Trek universe exhibit a specialized form of eusociality, as they are interconnected through a computer network and operate as a single organism.

• The Aparoids from Star Fox Assault are similar to the Borg, with a queen driving the actions of an entire race of insect-like living machines.

• The Formics or "Buggers" in Orson Scott Card's Ender's Game Series are eusocial.

• The Tyranids Of Warhammer 40.000 are propably Eusocial.

Stephen Baxter at the Science-Fiction-Tage NRW in Dortmund, Germany, March 1997 Stephen Baxter (born in Liverpool, 13 November 1957) is a British hard science fiction author. ... Coalescent (ISBN 057507423X) is a science-fiction novel by Stephen Baxter. ... The xenomorph as it appears in Alien vs. ... Alien (1979), directed by Ridley Scott, is an extremely popular and influential science fiction/horror film that spawned several sequels and imitators. ... Nac Mac Feegles on the cover of The Wee Free Men The Nac Mac Feegle (also known as Pictsies, the Wee Free Men, the Little Men, or Person or Persons Unknown, Believed to be Armed) are a fictional type of fairy appearing in Terry Pratchetts Discworld novels Carpe Jugulum... Terence David John Pratchett OBE (born April 28, 1948, in Beaconsfield, Buckinghamshire, England[1]) is an English fantasy author, best known for his Discworld series. ... // This article is about the novels. ... Oddworld is a comprehensive fictional universe presented in videogame form, created by game developers Oddworld Inhabitants under the direction of Lorne Lanning. ... A Zerg Hydralisk The Zerg are a vaguely insectoid race in the StarCraft universe. ... StarCraft is a real-time strategy computer game by Blizzard Entertainment. ... Families Suborder Mesothelae     Liphistiidae (primitive burrowing spiders) Suborder Mygalomorphae     Atypidae (atypical tarantula)     Antrodiaetidae (folding trapdoor spider)     Mecicobothriidae (dwarf tarantulas)     Hexathelidae (venomous funnel-web tarantula)     Dipluridae (funnel-web tarantula)     Cyrtaucheniidae (wafer trapdoor spider)     Ctenizidae (trapdoor spider)     Theraphosidae (tarantula) Suborder Araneomorphae     Hypochilidae (lampshade spider)     Filistatidae (crevice weaver)     Sicariidae (recluse spider)     Scytodidae (spitting... Arachnophobia was an American horror film released in 1990 directed by Frank Marshall and starring John Goodman and Jeff Daniels. ... Serpents Reach (1985 re-issue). ... The Alliance-Union universe is a fictional universe developed by Science fiction and Fantasy author C. J. Cherryh. ... This article or section does not cite any references or sources. ... The current Star Trek franchise logo Star Trek is an American science fiction entertainment series. ... Star Fox: Assault is the newest entry in the long-running Star Fox series of video games for Nintendo consoles. ... Formics, usually referred to by the pejorative term buggers, are a fictional insectoid alien species from the Enders Game series of science fiction novels by Orson Scott Card. ... Orson Scott Card (born August 24, 1951)[1] is an American author, working in numerous genres. ... The Enders Game Series (or simply Ender Series) is a series of science fiction books by Orson Scott Card, started with the short story Enders Game, which was later expanded into the novel Enders Game. ...

See also

• Altruism
• Altruism in animals
• Subsociality
• Evolution
• Gyne
• Presociality
• Reciprocity
• Sociobiology
• Stigmergy
• Sydney Skaife

For the ethical doctrine, see Altruism (ethics). ... Altruism is a well-documented animal behaviour, which appears most obviously in kin relationships but may also be evident amongst wider social groups. ... Subsociality among insects means parental behaviour. ... This article is about evolution in biology. ... Gyne is the reproductive female caste of social insects (especially ants and bees). ... wolfs live and hunt in presocial packs A wasp from the family Sphecidae, which includes a number of primitively social species Presociality is a phenomenon in which animals exhibit more than just sexual interactions with members of the same species; however, they fall short of qualifying as eusocial. ... This is a disambiguation page — a navigational aid which lists other pages that might otherwise share the same title. ... Sociobiology is a synthesis of scientific disciplines that explains behaviour in all species by considering the evolutionary advantages of social behaviours. ... Stigmergy is a method of communication in decentralised systems in which the individual parts of the system communicate with one another by modifying their local environment. ... Sydney Skaife Sydney Skaife Sydney Harold Skaife (Stacey) D.Sc FRSSAf. ...

External links

• International Union for the Study of Social Insects

References

1. E.O. Wilson and Bert Hölldobler The Ants, 1990, Belknap Press, ISBN 0-674-04075-9, Winner of the Pulitzer Prize