[{"@context":"http:\/\/schema.org\/","@type":"BlogPosting","@id":"https:\/\/wiki.edu.vn\/all2en\/wiki32\/homology-evolution-wikipedia\/#BlogPosting","mainEntityOfPage":"https:\/\/wiki.edu.vn\/all2en\/wiki32\/homology-evolution-wikipedia\/","headline":"Homology (evolution) – Wikipedia","name":"Homology (evolution) – Wikipedia","description":"In biology of evolution, a homology designates an evolutionary link between two traits (generally anatomical) observed in two different species,","datePublished":"2021-02-28","dateModified":"2021-02-28","author":{"@type":"Person","@id":"https:\/\/wiki.edu.vn\/all2en\/wiki32\/author\/lordneo\/#Person","name":"lordneo","url":"https:\/\/wiki.edu.vn\/all2en\/wiki32\/author\/lordneo\/","image":{"@type":"ImageObject","@id":"https:\/\/secure.gravatar.com\/avatar\/44a4cee54c4c053e967fe3e7d054edd4?s=96&d=mm&r=g","url":"https:\/\/secure.gravatar.com\/avatar\/44a4cee54c4c053e967fe3e7d054edd4?s=96&d=mm&r=g","height":96,"width":96}},"publisher":{"@type":"Organization","name":"Enzyklop\u00e4die","logo":{"@type":"ImageObject","@id":"https:\/\/wiki.edu.vn\/wiki4\/wp-content\/uploads\/2023\/08\/download.jpg","url":"https:\/\/wiki.edu.vn\/wiki4\/wp-content\/uploads\/2023\/08\/download.jpg","width":600,"height":60}},"image":{"@type":"ImageObject","@id":"https:\/\/upload.wikimedia.org\/wikipedia\/commons\/thumb\/6\/64\/Handskelett_MK1888.png\/350px-Handskelett_MK1888.png","url":"https:\/\/upload.wikimedia.org\/wikipedia\/commons\/thumb\/6\/64\/Handskelett_MK1888.png\/350px-Handskelett_MK1888.png","height":"166","width":"350"},"url":"https:\/\/wiki.edu.vn\/all2en\/wiki32\/homology-evolution-wikipedia\/","wordCount":3591,"articleBody":"In biology of evolution, a homology designates an evolutionary link between two traits (generally anatomical) observed in two different species, which is due to the fact that both inherited it with a common ancestor. These features are then said homologues . It can be anatomical, or molecular (homologous proteins) characters. This term also extends to genetic sequences (DNA). The term homology is a fundamental concept for biology with regard to the organization of an organization. It is also a very vague and complex subject because it is explained differently depending on the scientific community. Homology was identified, by hall in 2000, as one of the five most important elements in the field of evolutionary development. In terms of evolutionary biology of development, the term homology is used to explain the similar and repetitive structures of an organism through several generations. According to Van Valen, Homology is the correspondence caused by a continuity of information for structures within an organization or between organizations. The concept of homology is little known and little developed by biologists, especially at the molecular level. Despite, the numerous definitions describing homology, there is still none which is accepted by all biologists. Do not confuse with the definition of domain homology in comparative and evolutionary biology. In contrast, features analogues are similar features in shape but that appeared independently during the history of life: for example the wings of birds, bats, or insects.   General case in different species [ modifier | Modifier and code ]  Certain morphological or anatomical structures constituting an organism have been acquired very early in the history of the evolution of species and have given birth to modified structures but all deriving from a common initial structure.For example, the members of tetrapod vertebrates (all species with four members) derive from an ancestral member and have given rise to variations (bird wings, mammal legs …) in which it is possible to Find an initial boss (the Chiridist member). In particular, this is the case, for example, of the anterior leg of a horse and the pectoral fin of a dolphin, who have as a common ancestor a mammal (who, 80 million years ago, looked like Probably at a chevrotain [ first ] ), which had four members like these two animals and it is the previous member of this primitive mammal which gave the paw of the horse and the finish of the dolphin.  Demonstrates the three hypotheses concerning the evolution of the segmentation of bilaterals. Hypothesis 1 proposes that the segmentation character has been acquired independently. Hypothesis 2 offers a homology of segmentations between prostostomas and chord\u00e9s. Hypothesis 3 offers a homology of segmentations among all bilaterals. Currently, with regard to the evolution of the segmentation of bilaterals, three hypotheses are postulated by several biologists. The first does not relate to homology, but the last two hypotheses demonstrate a homology. The second postulates that there is a homology of the segmentations among the protostomians and the Chord\u00e9s, but that several of the branches have lost this segmentation. The last postulates that he has a homology among bilaterals but that later, even more branching lost this segmentation. Despite the similarities found in the various linked organizations, there is not enough evidence and research to conclude the homology of segmentations. For example, in the evaluation of the second hypothesis, the generated gene, known for expressing segmental bands in arthropods, was considered as a homologist in annelides and arthropods. Its expression in the Ann\u00e9lides seems to play a role in segmentation, but since it is expressed after the separation of the ganglionic primordium, its role in the segmentation process is doubtful. In the case of evaluation of the third hypothesis, the gene her1 Found in fish-zebles is presumed to be the orthologist of the Pair-Rule gene (peer-ul gene) hairy , Responsible for the development of embryonic segments in insects, because he imitates his expression boss. This suggests that the common ancestor of protostomians and deuterostomians was segmented, so the segments of all bilaterals are homologous. Unfortunately, it is not yet certain if the gene her1 Fish-zebles is currently the orthologist of the Peir-Rule Hairy gene. Other examples : The bat wing is a counterpart at the anterior paw of the Taupe; Despite the difference in size, the skeleton of the hummingbird is homologous to that of the whale [ 2 ] ; The natatory bladder of fish is homologous to the lungs of air vertebrates; The oral pieces of insects, so diverse from one order to another, are homologous organs; The homologies meet between the reproductive elements of vascular plants (pteridophytes, gymnosperms, angiosperms). When two traits appear independently in two taxa without being the inheritance of a common ancestor like the wings of insects and those of birds, we speak of analogy or homoplasia. Specific case in the same organization [ modifier | Modifier and code ] When the same character is present several times in the same organism we speak of serial homology. For example the previous and posterior limbs of a tetrapod are homologous because they have the same structure but are not from the same common ancestral organ because present simultaneously on the same organism. The case of metamery is also an example. This case is very similar to a “duplication” of characters in the same organism and therefore, as in the case of genes, this can be considered as a case of paralogy. For example, for mammal hair, rat and cat viboses will be closer to each other than cat vibrish compared to a hair of the same cat. In genetics of diploid beings, each of the two chromosomes of a pair are homologous, one being inherited from the male gamete (“father”) and the other of the female gamete (“mother”).Indeed, in the fertilized egg, the diploid state results from the meeting of a batch of chromosomes of paternal origin and a batch of chromosomes of maternal origin, which associated by pairs are homologous two by two. Regarding genetic relations within a unique organization, the Drosophile is an example. There is a genetic homology in heterochromatin among all the chromosomes of Drosophila melanogaster . More specifically, this homology is located between chromosome I and chromosome IV. Homologous proteins are proteins whose genes which code them have a common origin. We recognize two homologous proteins because they have close space structures and amino acid sequences that have similarities. The functions of these proteins can be more or less similar. We can quantify the degree of homology between proteins by performing an alignment of optimal sequence, for example by means of the Smith-Waterman algorithm and similarity matrices to quantify the resemblance between amino acids. We can find homologous proteins in different species, this is the case with vertebrate globines. This reflects the common origin of several species and therefore evolution. We can find homologous proteins in the same species, this is the case of alpha and beta globines that make up human hemoglobin. This shows that evolution can be due to a complexification of genomes. In molecular biology, it is mainly genes and proteins that are considered homologous. For example, histones, actin, tubulin, and proteins with unique functions in eukaryotic cells, are homologous in animals, plants and fungi. It is a genetic relationship resulting from a hereditary modification of a structure which occurred only once. It can be between organisms or within a unique organization. This definition differs from that of Van Valen because it specifies structures as genetic, and the continuity of information as heredity. Molecular homology can vary on several levels of organization, all interdependent. Thus, recognition of homology at DNA implies homology in terms of amino acid sequences, and vice versa. The different levels of organization also include the position of the individual nucleotides of the DNA sequences as well as the interaction of the sequences during the expression of the gene. The expression of a genetic system is considered homologous when it has been inherited from an organism bearing the common genetic system. To recognize DNA homologies, only sequence information is used. This is done by comparing the parallel strands of two gene elements. Thus, the recognition of molecular homology depends on the search for relevant similarities through the sequences. Take the example of the Homology Study between Mouse and Drosophilia. A homology was found between the oncogen int-1 mammary mouse and gene glands wingless Drosophils. The gene int-1 is the gene of a virus found in the breast tumors of a mouse. The gene wingless As for him intervenes in morphogenesis and segmental polarity in the Drosophile. During the study, the gene counterpart int-1 was found in the drosophilic genome, located in the same cytological position as the gene wingless . Thus, the counterpart of the gene int-1 and the gene wingless have the same sequences so they code homologous proteins. When the sequence of int-1 is expressed in the Drosophila, it expresses the gene phenotype wingless . Another study [Ref. necessary] was interested in strains E.coli And Salmonella typhimurium Resistant to apramycin and gentamicin taken from hospitals and patients. In order to compare the plasmids of these bacteria from animals and humans, the molecular relationship between apramycin and genamicin was studied. Several strains of animals and humans have been identified as E.coli And Salmonella typhimurium , and were all resistant to gentamicin and apramycin. Thus, a genetic homology has been discovered, that is to say, the plasmids of animals and humans code the same protein, Aminoglycosidase 3-N-acetyltransferase. Several genes of the gene T-box Brachyury ( in ) have recently been isolated from various organisms, from cnidaries to vertebrates and insects. It has a role in the process of differentiation of the posterior mesoderm and the formation of the notochord, then of the elongation of the posterior axis. The counterpart of Brachyury was notably analyzed in a member of the lophroTrochazoa, Platynereis . The gene is expressed along the old blastopore in the shape of a slit and continues to be expressed in the anterior and posterior larval intestine after gastrulation. This expression is similar to that of the basal larva of deuterostomians, like the starfish Asterina , indicating that he has a homology between deuterostomians and protostomians in relation to the development of the anterior larval intestine. Another example concerning Deuterostomians and Protostomians shows a homologous expression of genes coding transcription factors and signaling molecules. This homology concludes that certain parts of the body of insects and vertebrates are homologous. In particular, genes Wnt\/TCF, Dpp or TGF\u03b2\/MADS, TollR\/Rel Factor, Hedgehog\/Ci, Nuclear Receptor, Jack\/Stat are all similar to deuterostomians and eco -trusses. In short, the signaling transduction routes such as membrane surface receptors and transcription factors are all orthologists through bilaterals. In addition, CNIDARY AND BILATERAL taxa demonstrate a bilateral symmetry caused by homologous hox expressions along the primary axis of the body and the asymistrical homologous expressions along the secondary axis of the body. The HOX gene determines the pattern of the anteri-posterior axis, and the DPP gene is involved in dorsal-ventral modeling in bilateral There may be segmental homology within the group of arthropods, this is the case for the counterparts of each of the eight genes of the Drosophile [ 3 ] . Orthologue [ modifier | Modifier and code ] Two homologous sequences of two different species are orthologists if they descend from a single sequence present in the last ancestor common to the two species. The term orthologue was proposed by Walter Fitch in 1970. For example, the gene caudal of the Drosophile and its counterpart, the gene Cdx at the beetle Tribolium castaneous , the locust Gregaria shistocher and the crustacean Artemiafranciscana . The main role of the gene caudal is the development of the posterior region of the body. When the gene was removed by one (interferent RNA) from beetles and crustaceans, they were devoid of chest and abdominal segments, and posterior, genitals and post-G\u00e9nitals chest segments. This confirms the involvement of the gene caudal in the characterization of the posterior region. Paralogue [ modifier | Modifier and code ] Two homologous sequences within a species (or different species [ 4 ] ) are paralogous if they result from a gene duplication. Inparalogue [ modifier | Modifier and code ] Two paralogical sequences within a species are inparalogues if the duplication event took place after the speciation [ 5 ] . Outparalogue [ modifier | Modifier and code ] Two paralogical sequences within a species are outparalogues if the duplication event took place before the speciation. Ohnologue [ modifier | Modifier and code ] Two paralogous sequences are ohnologists if they result from a complete duplication event of the genome. The term ohnologist was proposed by Ken Wolfe in tribute to Susumu Ohno [ 6 ] . Xenologist [ modifier | Modifier and code ] Two homologous sequences are xenologists when they result from a horizontal transfer of gene between two organisms. \u2191 (in)  Placental mammal diversification and the Cretaceous-Tertiary boundary . Springer MS, Murphy WJ, Eizirik E, O’Brien SJ. Proc Natl Acad Sci U S A. 2003 Feb 4;100(3):1056-61.  \u2191 Cyril Langlois, “Paleontological facts and arguments in favor of evolution” .  \u2191 Cornec, J. P., & Gilles, A., \u00ab\u00a0 Urbilateria, an evolved being? \u00bb, M\/s: science medicine , n O 22 (5), 2006 , p. 493-51  \u2191 Fitch WM. Homology: a personal view on some of the problems. Trends Genet. 2000 May;16(5):227-31 [first]  \u2191 Sonnhammer EL, Koonin EV. Orthology, paralogy and proposed classification for paralog subtypes. Trends Genet. 2002 Dec;18(12):619-20 [2]  \u2191 Ken Wolfe (2000) Robustness\u2014it’s not where you think it is. Nature Genetics May;25(1):3-4. [3]  On other Wikimedia projects: Bibliography [ modifier | Modifier and code ] John V. Freudenstein, Characters, States, and homology , Systematic biology, 2005. Jacob, F. (1990). Living unity. Hall, B. K. (2003). Evo-Devo: evolutionary developmental mechanisms.International Journal of Developmental Biology, 47(7\/8), 491-496. Davis, G. K., & Patel, N. H. (1999). The origin and evolution of segmentation.Trends in Genetics, 15(12), M68-M72. Technau, U. (2001). Brachyury, the blastopore and the evolution of the mesoderm. Bioessays, 23(9), 788-794. Bledsoe, A. H., & Sheldon, F. H. (1990). Molecular homology and DNA hybridization. Journal of molecular evolution, 30(5), 425-433. Erwin, D. H., & Davidson, E. H. (2002). The last common bilaterian ancestor.Development, 129(13), 3021-3032. Chaslus-Dancla, E., Pohl, P., Meurisse, M., Marin, M., & Lafont, J. P. (1991). High genetic homology between plasmids of human and animal origins conferring resistance to the aminoglycosides gentamicin and apramycin.Antimicrobial agents and chemotherapy, 35(3), 590-593. Falkow, S., Rownnd, R., & Baron, L. S. (1962). genetic homology between escheria coli k-12 and salmonella. Journal of Bacterology, 84(6), 1303-1 Newman, S. A. (2006). The developmental-genetic toolkit and the molecular homology-analogy paradox. Biological Theory, 1(1), 12. Finnerty, J. R., Pang, K., Burton, P., Paulson, D., & Martindale, M. Q. (2004). Origins of bilateral symmetry: Hox and dpp expression in a sea anemone.Science, 304(5675), 1335-1337. Sandler, L., & Novitski, E. (1956). Evidence for genetic homology between chromosomes I and IV in Drosophila melanogaster, with a proposed explanation for the crowding effect in triploids. Genetics, 41(2), 189. 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