Neoteny describes a process by which paedomorphism is achieved, and is a subject studied in the field of developmental biology. In neoteny, the physiological (or somatic) development of an animal or organism is slowed or delayed. Ultimately this process results in the retention, in the adults of a species, of juvenile physical characteristics well into maturity. Neoteny is derived from the Latin neotenia, derived from the prefix Greek neo-, meaning young, and teinein, to extend. A paedomorph is an organism that keeps physical and mental characteristics of its childhood in its adulthood. ... Developmental biology is the study of the process by which organisms grow and develop. ... Physiology (in Greek physis = nature and logos = word) is the study of the mechanical, physical, and biochemical functions of living organisms. ... The term somatic refers to the body. ... In biology, a species is the basic unit of biodiversity. ... Latin is an ancient Indo-European language originally spoken in the region around Rome called Latium. ...

Specific individual traits that differ in descendant organisms, when compared to ancestors, are sometimes called neotenies; humans, for example, appear to have several neotenies in comparison to chimpanzees. Trinomial name Homo sapiens sapiens Linnaeus, 1758 Humans, or human beings, are animals biologically classified as bipedal primates belonging to the mammalian genus Homo, in particular to its only extant species, Homo sapiens (Latin for wise man or knowing man), under the family Hominidae (the great apes). ... Type Species Simia troglodytes Blumenbach, 1775 Species Pan troglodytes Pan paniscus Chimpanzee, often shortened to chimp, is the common name for the two species in the genus Pan. ...

Neoteny in humans

There is controversy over whether adult humans exhibit certain neotenous features, or juvenile characteristics, that are not evidenced in other great ape species. Stephen Jay Gould was an advocate of the view that humans are a neotenous species of chimpanzee; the argument being that juvenile chimpanzees have an almost-identical bone structure to humans, and that the chimpanzee’s ability to learn seems to be cut off upon reaching maturity. Genera Subfamily Ponginae Pongo - Orangutans Gigantopithecus (extinct) Sivapithecus (extinct) Subfamily Homininae Gorilla - Gorillas Pan - Chimpanzees Homo - Humans Paranthropus (extinct) Australopithecus (extinct) Sahelanthropus (extinct) Ardipithecus (extinct) Kenyanthropus (extinct) Pierolapithecus (extinct) (tentative) The Hominids (Hominidae) are a biological family which includes humans, extinct species of humanlike creatures and the other great apes... To meet Wikipedias quality standards, this article or section may require cleanup. ...

While neoteny is not necessarily a physical state experienced by humans, paedomorphic characteristics in women are widely acknowledged as desirable by men (see Sexual attraction). Desmond Morris discusses the importance of neoteny in human sociobiology in The Naked Ape, The Human Animal, and the The Human Zoo. This article or section is incomplete and may require expansion and/or cleanup. ... Dr Desmond Morris (born 24 January 1928 in the village of Purton, UK) is most famous for his work as a zoologist and ethologist. ... Desmond Morris (born January 24th, 1928) is most famous for his work as a zoologist and ethologist. ... The Human Zoo is a book written by the British zoologist Desmond Morris, published in 1969. ...

It is also worthy to note that paedomorphic variations not only exist between the sexes, but also between individuals, with some people displaying more characteristics of neoteny than others. This trend carries over to variations among ethnic groups as well.

Animal kingdom

One example of a neotenic trait in vertebrates is the salamander species axolotl, which usually remains fully aquatic as it matures. Vertebrata is a subphylum of chordates, specifically, those with backbones or spinal columns. ... Suborders Cryptobranchoidea Salamandroidea Sirenoidea Salamander is the common name applied to approximately 500 amphibian vertebrates with slender bodies, short legs, and long tails (order Caudata or Urodela). ... Binomial name Ambystoma mexicanum (Shaw, 1789) The Axolotl (Ambystoma mexicanum) is an aquatic salamander native to Mexico. ...

It is also theorized that the phylum Chordata first originated as a result of paedomorphism occurring in a highly primitive animal such as a sponge or coral. Phylum (plural: phyla) is a taxon used in the classification of life, adopted from the Greek phylai the clan-based voting groups in Greek city-states. ... Typical Classes Subphylum Urochordata - Tunicates Ascidiacea Thaliacea Larvacea Subphylum Cephalochordata - Lancelets Subphylum Myxini - Hagfishes Subphylum Vertebrata - Vertebrates Petromyzontida - Lampreys Placodermi (extinct) Chondrichthyes - Cartilaginous fishes Acanthodii (extinct) Actinopterygii - Ray-finned fishes Actinistia - Coelacanths Dipnoi - Lungfishes Amphibia - Amphibians Reptilia - Reptiles Aves - Birds Mammalia - Mammals Chordates (phylum Chordata) include the vertebrates, together with... A paedomorph is an organism that keeps physical and mental characteristics of its childhood in its adulthood. ... Classes Calcarea Hexactinellida Demospongiae The sponges or poriferans (from Greek poros pore and ferro to bear) are animals of the phylum Porifera. ... Subclasses Alcyonaria Zoantharia See text for orders. ...

Neoteny and progenesis

Neoteny and progenesis are both mechanisms that result in paedomorphosis. Neoteny delays physiological and sexual maturity. Comparatively, progenesis halts development of the organism before achieving the adult maturity experienced by its ancestors. Progenetic organisms achieve sexual maturity in this juvenile state and is found among certain amphibians and insects. Progenesis is a mechanism in developmental biology that is associated with paedomorphosis. ... Paedomorphosis is a biological term describing the retention of ancestral infantile or juvenile traits in an adult organism. ... Progenesis is a mechanism in developmental biology that is associated with paedomorphosis. ... For other uses, see Amphibian (disambiguation). ... Classes & Orders See taxonomy Insects are invertebrate animals of the Class Insecta, the largest and (on land) most widely-distributed taxon within the phylum Arthropoda. ...

Evolution

Neoteny also plays a role in evolution, as a means by which, over generations, a species can undergo a significant physical change. In such cases, a species’ neotenous form becomes its “normal” mature form, no longer dependent upon environmental triggers to inhibit maturity. The mechanism for this could be a mutation in, or interactions between, genes involved in maturation, inhibiting their function. A speculative phylogenetic tree of all living things, based on rRNA gene data, showing the separation of the three domains, bacteria, archaea and eukaryotes. ... In biology, mutations are changes to the genetic material (usually DNA or RNA). ... This stylistic schematic diagram shows a gene in relation to the double helix structure of DNA and to a chromosome (right). ...

To be neotenous needs a realisation of its condition. It effects all the primates. Most of the chimps studied, for example, lose their neoteny at about 2-3 years. Most adult humans lose their neoteny between the 14th and 17th year. But in some, neoteney remains; and that is a quest to learn and get better and find out things.

Neoteny is not the only contributing factor affecting maturation in species that may have undergone neotenous changes over the course of their evolution, and its actual involvement in the following examples is not well understood:

• flightless birds—physical proportions resemble those of the chicks of flighted birds;
• humans—with traits such as sparse body hair and enlarged heads reminiscent of baby primates.
• dogs—which share many physical features with the immature wolf

Orders Many - see section below. ... Trinomial name Homo sapiens sapiens Linnaeus, 1758 Humans, or human beings, are animals biologically classified as bipedal primates belonging to the mammalian genus Homo, in particular to its only extant species, Homo sapiens (Latin for wise man or knowing man), under the family Hominidae (the great apes). ... Trinomial name Canis lupus familiaris (Linnaeus, 1758) Puppy redirects here. ... Wolf Wolf Man Mount Wolf Wolf Prizes Wolf Spider Wolf 424 Wolf 359 Wolf Point Wolf-herring Frank Wolf Friedrich Wolf Friedrich August Wolf Hugo Wolf Johannes Wolf Julius Wolf Max Franz Joseph Cornelius Wolf Maximilian Wolf Rudolf Wolf Thomas Wolf As Name Wolf Breidenbach Wolf Hirshorn Other The call...

See also

• Autism
• Cuteness
• Heterochrony
• Paedogenesis

Autism is classified as a neurodevelopmental disorder that manifests itself in markedly abnormal social interaction, communication ability, patterns of interests, and patterns of behavior. ... Cuteness, exhibited here by a teddy bear and a dog. ... In biology, heterochrony is defined as a developmental change in the timing of events, leading to changes in size and shape. ... Paedogenesis is the act of reproduction by an organism that has not achieved physical maturity. ...

External links

• DannyReviews.com—Ontogeny and Phylogeny, Stephen Jay Gould (book review), Danny Yee (October 16, 1992)
• DavidBrin.com—“Neoteny and Two-Way Sexual Selection in Human Evolution: A Paleo-Anthropological Speculation on the Origins of Secondary-Sexual Traits, Male Nurturing and the Child as a Sexual Image,” David Brin, PhD
• Neoteny.org—“Neoteny: The multidisciplinary implications of heterochronic theory”
• NIH.gov—“Ontogenetic study of the skull in modern humans and the common chimpanzees: neotenic hypothesis reconsidered with a tridimensional Procrustes analysis,” X. Penin, C. Berge, M. Baylac, American Journal of Physical Anthropology, vol 118, no 1, p 50-62 (May, 2002)
• NHM.org—“Neoteny/Juvenilization: Some dogs look and act forever young,” Natural History Museum of Los Angeles County