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The most familiar examples are insects such as ants, bees, and wasps (the order Hymenoptera), with reproductive queens and sterile workers. Eusociality may be easier for these species to evolve due to their haplodiploidy, which increases the significance of kin selection. This complex mechanism of sex determination gives rise to what W. D. Hamilton first termed "supersisters" who share 75 per cent of their genes. 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, there is a genetic advantage to raising more sisters.

It is thought that eusociality evolved 11 separate times within the order of Hymenoptera. The Hymenoptera are often referred to as "social insects", but it is now preferred to use the term "eusocial insects" for those species that exhibit eusociality, and not to apply the term "social insects" to other Hymenoptera: it is important to realise that not all the Hymenoptera are eusocial.

Another extremely widespread insect group exhibiting eusociality are the termites (order Isoptera). Eusociality is also known among mammals: the naked mole rat is a clear case, and, less rigorously some canids can be argued to be eusocial, since only the alpha male and female will breed. In this case, the other members of the pack are not sterile, but are dissuaded from breeding by aggressive behavior on the part of the breeding pair.

Eusociality has arisen among some crustaceanCrustaceans Hyalella azteca Scientific classification Kingdom: Animalia Phylum: Arthropoda Subphylum Crustacea Classes Remipedia Cephalocarida Branchiopoda Ostracoda Maxillopoda Malacostraca The crustaceans (Crustacea) are a large group of arthropods (55,s and other arthropodSubphylum Trilobitomorpha Trilobita Trilobites (extinct) Subphylum Chelicerata Arachnida Spiders, Scorpions, etc. Merostomata Horseshoe crabs, etc. Pycnogonida Sea Spiders Subphylum Myriapoda Chilopoda Centipedes Diplopoda Millipedes Pauropoda Symphyla Sus. On some tropical reefs, several species of minute synalpheid 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.

Eusociality represents the most extreme form of kin altruismAltruism is an unselfish interest in helping someone else or simply behavior that benefits someone else while affecting the actor detrimentally or neutrally. The former type of altruism is a motivation that emphasizes the welfare of others while minimizin. The analysis of eusociality played a key role in the development of theories in sociobiologySociobiology is a branch of biology that attempts to throw light upon animal behavior and social structures in terms of evolutionary advantage or strategy. It uses techniques from ethology, evolution and population genetics. The term "sociobiology" was co.

In spite of the obvious advantages of common foraging and defense, eusocial animals present a seeming paradox, which troubled DarwinCharles Robert Darwin ( February 12, 1809 April 19, 1882) was an English naturalist whose revolutionary theory laid the foundation for both the modern theory of evolution and the principle of common descent by proposing natural selection as a mechanism.: if adaptive evolution unfolds by differential survival of successful species, how can a species succeed in which most individuals don't breed at all? 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 had to wait for the discovery of the mechanisms for genetic inheritance.