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Encyclopedia > Recapitulation theory

The theory of recapitulation, also called the biogenetic law or ontogeny recapitulates phylogeny, is a theory in biology which attempts to explain apparent similarities between humans and other animals. First espoused in 1866 by German zoologist Ernst Haeckel, a contemporary of Charles Darwin, the theory has been discredited in its absolute form ("strong recapitulation"), although recognized as being perhaps partly fruitful. In biology, ontogeny is the embryonal development process of a certain species, and phylogeny a species' evolutionary history. Observers have noted various connections between phylogeny and ontogeny, explained them with evolutionary theory and taken them as supporting evidence for that theory. Ontogeny (also ontogenesis or morphogenesis) describes the origin and the development of an organism from the fertilized egg to its mature form. ... In biology, phylogenetics (Greek: phylon = tribe, race and genetikos = relative to birth, from genesis = birth) is the study of evolutionary relatedness among various groups of organisms (e. ... Biology studies the variety of life (clockwise from top-left) E. coli, tree fern, gazelle, Goliath beetle Biology (from Greek Βìο meaning life and Λoγος meaning the study of) is the study of life. ... Human beings are defined variously in biological, spiritual, and cultural terms, or in combinations thereof. ... 1866 (MDCCCLXVI) is a common year starting on Monday of the Gregorian calendar or a common year starting on Wednesday of the 12-day-slower Julian calendar. ... Ernst Haeckel. ... Charles Robert Darwin (12 February 1809 – 19 April 1882) was an eminent English naturalist who achieved lasting fame by convincing the scientific community that species develop over time from a common origin. ... Biology studies the variety of life (clockwise from top-left) E. coli, tree fern, gazelle, Goliath beetle Biology (from Greek Βìο meaning life and Λoγος meaning the study of) is the study of life. ... Ontogeny (also ontogenesis or morphogenesis) describes the origin and the development of an organism from the fertilized egg to its mature form. ... It has been suggested that embryology be merged into this article or section. ... In biology, a species is one of the basic units of biodiversity. ... In biology, phylogenetics (Greek: phylon = tribe, race and genetikos = relative to birth, from genesis = birth) is the study of evolutionary relatedness among various groups of organisms (e. ... This article is about evolution in biology. ...

Contents

Haeckel's theory

Ontogeny is the growth (size change) and development (shape change) of an individual organism; phylogeny is the evolutionary history of a species. Haeckel's recapitulation theory claims that the development of the individual of every species fully repeats the evolutionary development of that species. Otherwise put, each successive stage in the development of an individual represents one of the adult forms that appeared in its evolutionary history. Haeckel formulated his theory as such: "Ontogeny recapitulates phylogeny". This notion later became simply known as recapitulation. Download high resolution version (915x800, 187 KB)Embryo drawings drawn by Haeckel in 1866 for his Recapitulation theory. ... Download high resolution version (915x800, 187 KB)Embryo drawings drawn by Haeckel in 1866 for his Recapitulation theory. ... Ernst Haeckel. ... This article or section is in need of attention from an expert on the subject. ... Ontogeny (also ontogenesis or morphogenesis) describes the origin and the development of an organism from the fertilized egg to its mature form. ... In biology, phylogenetics (Greek: phylon = tribe, race and genetikos = relative to birth, from genesis = birth) is the study of evolutionary relatedness among various groups of organisms (e. ... This article is about evolution in biology. ...


Haeckel produced several embryo drawings that often overemphasized similarities between embryos of related species. These found their ways into many biology textbooks, and into popular knowledge. This article or section is in need of attention from an expert on the subject. ...


For example, Haeckel believed that the human embryo with gill slits (pharyngeal arches) in the neck not only signified a fishlike ancestor, but represented an adult "fishlike" developmental stage. Embryonic pharyngeal arches are not gills and do not carry out the same function. They are the invaginations between the gill pouches or pharyngeal pouches, and they open the pharynx to the outside. Gill pouches appear in all tetrapod animal embryos. In mammals, the first gill bar (in the first gill pouch) develops into the lower jaw (Meckel's cartilage), the malleus and the stapes. In a later stage, all gill slits close, with only the ear opening remaining open. For a technical discussion on the topic, see [1]. Schematic of developing fetus with first, second and third arches labeled. ... gills of a Smooth Newt Gills inside of a tuna head In aquatic organisms, gills are a respiratory organ for the extraction of oxygen from water and for the excretion of carbon dioxide. ... Invagination is one of the morphogenetic processes by which an embryo takes form, and is the initial step of gastrulation, the massive reorganization of the embryo from a simple spherical ball of cells, the blastula, into a multi-layered organism, with a differentiated endoderm, mesoderm, and ectoderm. ... The pharynx (plural: pharynges) is the part of the neck and throat situated immediately posterior to the mouth and nasal cavity, and cranial to the esophagus, larynx, and trachea. ... Groups See text. ... I smoke weed im growing a blue penis dude#REDIRECT penises are cool ... Human jaw front view Human jaw left view Human jaw top view The jaw is either of the two opposable structures forming, or near the entrance to, the mouth. ... The cartilaginous bar of the mandibular arch is formed by what are known as Meckel’s cartilages (right and left) ; above this the incus is developed. ... The malleus is hammer-shaped small bone or ossicle of the middle ear which connects with the incus and is attached to the inner surface of the eardrum. ... The stapes or stirrup is the stirrup-shaped small bone or ossicle in the middle ear which attaches the incus to the fenestra ovalis, the oval window which is adjacent to the vestibule of the inner ear. ...


Rejection

Modern biology rejects the literal and universal form of Haeckel's theory. Although humans share ancestors with many other taxa (roughly, fish through reptiles to mammals), stages of human embryonic development are not functionally equivalent to the adults of these shared common ancestors. In other words, no cleanly defined and functional "fish", "reptile" and "mammal" stages of human embryonal development can be discerned. Moreover, development is nonlinear. For example, during kidney development, at one given time, the anterior region of the kidney is less developed (nephridium) than the posterior region (nephron). Homo sapiens (Latin: wise man) is the scientific name for the human species. ... The kidneys are bean-shaped excretory organs in vertebrates. ... Nephridia are invertebrate organs which function similarly to kidneys. ... A nephron is the basic structural and functional unit of the kidney. ...


The fact that contemporary biologists reject the literal or universal form of recapitulation theory has sometimes been used as an argument against evolution by some creationists. The argument is: "Haeckel's hypothesis was presented as supporting evidence for evolution, Haeckel's theory is wrong, therefore evolution has less support". This argument is not only an oversimplification but misleading because modern biology does recognize numerous connections between ontogeny and phylogeny, explains them using evolutionary theory without recourse to Haeckel's specific views, and considers them as supporting evidence for that theory. This article is about evolution in biology. ... The Creation of Light by Gustave Doré. Creation refers to the concept that all humanity, life, the Earth, or the universe as a whole was created by a deity (often referred to as God). ... Ontogeny (also ontogenesis or morphogenesis) describes the origin and the development of an organism from the fertilized egg to its mature form. ... In biology, phylogenetics (Greek: phylon = tribe, race and genetikos = relative to birth, from genesis = birth) is the study of evolutionary relatedness among various groups of organisms (e. ...


Unfortunately, some older editions of textbooks in the United States still erroneously cite recapitulation theory or the Haeckel drawings as evidence in support of evolution without appropriately explaining them as being misleading or outdated. Because the actual scientific theory is difficult to explain in layman's terms, expressions of doubt about evolution that point to the flaws in Haeckel's arguments typically go unchallenged in popular media. This page is a candidate to be moved to Wiktionary. ...


Historical impact

Although Haeckel's specific form of recapitulation theory is now discredited among biologists, it did have a strong impact in social and educational theories of the late 19th century. Alternative meaning: Nineteenth Century (periodical) (18th century — 19th century — 20th century — more centuries) As a means of recording the passage of time, the 19th century was that century which lasted from 1801-1900 in the sense of the Gregorian calendar. ...


English philosopher Herbert Spencer was one of the most energetic promoters of evolutionary ideas to explain pretty well everything in sight; He compactly expressed the basis for a cultural recapitulation theory of education in the following claim:[1] Herbert Spencer. ...

If there be an order in which the human race has mastered its various kinds of knowledge, there will arise in every child an aptitude to acquire these kinds of knowledge in the same order.... Education is a repetition of civilization in little.

[2]

The maturationist theory of G. Stanley Hall was based on the premise that growing children would recapitulate evolutionary stages of development as they grew up and that there was a one-to-one correspondence between childhood stages and evolutionary history, and that it was counterproductive to push a child ahead of its development stage. The whole notion fit nicely with other social Darwinist concepts, such as the idea that "primitive" societies needed guidance by more advanced societies, i.e. Europe and North America, which were the pinnacle of evolution. An early form of the law was devised by the 19th-century Estonian zoologist Karl Ernst von Baer, who observed that embryos resemble the embryos, but not the adults, of other species. Maturationism is an early childhood educational philosophy that sees the child as a growing organism and believes that the role of education is to passively support this growth rather than actively fill the child with information. ... Granville Stanley Hall (February 1, 1844, Ashfield, Massachusetts - April 24, 1924) was a psychologist and educationalist who pioneered American psychology. ... Social darwinism in the most basic form is the idea that biological theories can be extended and applied to the social realm. ... Zoology (Greek zoon = animal and logos = word) is the biological discipline which involves the study of animals. ... Karl Ernst von Baer (February 17, 1792 - November 26, 1876) was a Baltic German biologist and a founding father of embryology. ...


Modern observations

Generally, if a structure pre-dates another structure in evolutionary terms, then it also appears earlier than the other in the embryo. Species which have an evolutionary relationship typically share the early stages of embryonal development and differ in later stages. Examples include:

  • The backbone, the common structure among all vertebrates such as fish, reptiles and mammals, appears as one of the earliest structures laid out in all vertebrate embryos.
  • The cerebrum in humans, the most sophisticated part of the brain, develops last.

If a structure vanished in an evolutionary sequence, then one can often observe a corresponding structure appearing at one stage during embryonic development, only to disappear or become modified in a later stage. Examples include: Classes and Clades See below Vertebrates are members of the subphylum Vertebrata (within the phylum Chordata), specifically, those chordates with backbones or spinal columns. ... I smoke weed im growing a blue penis dude#REDIRECT penises are cool ... The telencephalon (te-len-seff-a-lon) is the technical name for a large region within the brain which is attributed many functions, which some groups would class as unique features which make humans stand out from other species. ... Homo sapiens (Latin: wise man) is the scientific name for the human species. ...

  • Whales, which have evolved from land mammals, don't have legs, but tiny remnant leg bones lie buried deep in their bodies. During embryonal development, leg extremities first occur, then recede. Similarly, whale embryos (like all mammalian embryos) have hair at one stage, but lose most of it later.
  • The common ancestor of humans and monkeys had a tail, and human embryos also have a tail at one point; it later recedes to form the coccyx.
  • The swim bladder in fish presumably evolved from a sac connected to the gut, allowing the fish to gulp air. In most modern fish, this connection to the gut has disappeared. In the embryonal development of these fish, the swim bladder originates as an outpocketing of the gut, and is later disconnected from the gut.

A Fin whale The term whale is ambiguous; it can refer to all cetaceans, to just the larger ones, or only to members of particular families within the order Cetacea. ... Young Girl Fixing her Hair, by Sophie Gengembre Anderson Hair is a filamentous outgrowth of dead cells from the skin, found only in mammals. ... The coccyx is formed of four fused vertebrae. ... The gas bladder (also fish maw, less accurately swim bladder or air bladder) is an internal organ that contributes to the ability of a fish to control its buoyancy, and thus to stay at the current water depth, ascend, or descend without having to waste energy in swimming. ... A giant grouper at the Georgia Aquarium Fish are aquatic vertebrates that are typically cold-blooded; covered with scales, and equipped with two sets of paired fins and several unpaired fins. ... For the Physics term GUT, please refer to Grand unification theory The gastrointestinal or digestive tract, also referred to as the GI tract or the alimentary canal or the gut, is the system of organs within multicellular animals which takes in food, digests it to extract energy and nutrients, and...

Modern theory

One can explain connections between phylogeny and ontogeny if one assumes that one species changes into another by a sequence of small modifications to its developmental program (specified by the genome). Modifications that affect early steps of this program will usually require the right modifications in later steps in order to produce an individual that survives and reproduces. Therefore, such successful combinations of changes are less likely to occur and most of the successful changes affect the latest stages of the program, and the earlier steps are retained. But occasionally, a modification of an earlier step in the program does succeed: for this reason ontogeny and phylogeny do not strictly correspond, unlike what Haeckel's original theory stated. In biology the genome of an organism is the whole hereditary information of an organism that is encoded in the DNA (or, for some viruses, RNA). ...


References

  • Division of Biology and Medicine, Brown University. Evolution and Development I: Size and shape.
  • Haeckel, E (1899). Riddle of the Universe at the Close of the Nineteenth Century.
  • Gerhard Medicus. The Inapplicability of the Biogenetic Rule to Behavioral Development (pdf).
  • Grigg, R. (1996). "Ernst Haeckel: evangelist for evolution and apostle of deceit". Creation 18 (2): 33–36.
  • Rebecca Irwin. Ontogeny and Phylogeny.
  • Richardson, M., et al. (1997). "There is no highly conserved stage in the vertebrates: implications for current theories of evolution and development.". Anatomy and Embryology 196 (2): 91-106.
  • Stephen Jay Gould (1977). Ontogeny and Phylogeny. Cambridge Mass.: Belknap Press of Harvard University Press. ISBN 0-674-63941-3. 

It has been suggested that Darwinian Fundamentalism be merged into this article or section. ...

Notes

  1. ^ Kieran Egan, The educated mind: How Cognitive Tools Shape Our Understanding., p.27 (University of Chicago Press, 1997, Chicago. ISBN 0-226-19036-6)
  2. ^ Herbert Spencer (1861). Education, p.5. 

The University of Chicago Press is the largest university press in the U.S. It is operated by the University of Chicago and publishes a wide variety of academic titles, including The Chicago Manual of Style, several academic journals including Critical Inquiry, and a wide array of texts covering academic...

External links

  • "Ontology Recapitulates Philology", a parody phrase

  Results from FactBites:
 
Recapitulation theory - Wikipedia, the free encyclopedia (1260 words)
The theory of recapitulation, also called the biogenetic law or ontogeny recapitulates phylogeny, is a theory in biology which attempts to explain apparent similarities between humans and other animals.
The fact that the literal form of recapitulation theory is rejected by modern biologists has sometimes been used as an argument against evolution by some creationists.
Although Haeckel's specific form of recapitulation theory is now discredited among biologists, it did have a strong impact in social and educational theories of the late 19th century.
  More results at FactBites »

 
 

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