{"title":"原始人谱系中臼齿大小和比例的变化:种间和种内研究。","authors":"L A D'Addona, V Bernal, P N Gonzalez","doi":"10.1093/iob/obae041","DOIUrl":null,"url":null,"abstract":"<p><p>The implications of the inhibitory cascade (IC) model in dental diversification have been primarily studied at an interspecific or higher level. In contrast, the study of organisms with recent evolutionary divergence or at an interpopulational scale is still very limited. Here, we assess the effect of changes in molar size and the ratio of local activators to inhibitors on molar proportions based on a compilation of data of crown diameters of the first, second, and third lower and upper molars of extinct and extant hominids and modern human populations. The analysis of allometric changes between the size of each tooth and the size of the molar row shows a negative allometry in first molars (M1), isometric changes in second molars (M2), and a positive allometry in third molars (M3) in both hominin phylogeny and modern human populations. On the other hand, the proportions of lower and upper molars of several hominid species fall outside the morphospace defined by the IC model, while most of the modern human populations fall within the morphospace defined by the model as M1 > M2 > M3. We conclude that there is a phylogenetic structuring for molar size, particularly in the maxilla, with a trend toward mesial-to-distal reduction in the molar row area accompanied by allometric changes. Our findings also show the limitations of the IC model for explaining molar proportions in primates, particularly the variation in the relative size at the interspecific scale in the hominid lineage.</p>","PeriodicalId":13666,"journal":{"name":"Integrative Organismal Biology","volume":"6 1","pages":"obae041"},"PeriodicalIF":2.2000,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11631436/pdf/","citationCount":"0","resultStr":"{\"title\":\"Variation in Molar Size and Proportions in the Hominid Lineage: An Inter- and Intraspecific Approach.\",\"authors\":\"L A D'Addona, V Bernal, P N Gonzalez\",\"doi\":\"10.1093/iob/obae041\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p><p>The implications of the inhibitory cascade (IC) model in dental diversification have been primarily studied at an interspecific or higher level. In contrast, the study of organisms with recent evolutionary divergence or at an interpopulational scale is still very limited. Here, we assess the effect of changes in molar size and the ratio of local activators to inhibitors on molar proportions based on a compilation of data of crown diameters of the first, second, and third lower and upper molars of extinct and extant hominids and modern human populations. The analysis of allometric changes between the size of each tooth and the size of the molar row shows a negative allometry in first molars (M1), isometric changes in second molars (M2), and a positive allometry in third molars (M3) in both hominin phylogeny and modern human populations. On the other hand, the proportions of lower and upper molars of several hominid species fall outside the morphospace defined by the IC model, while most of the modern human populations fall within the morphospace defined by the model as M1 > M2 > M3. We conclude that there is a phylogenetic structuring for molar size, particularly in the maxilla, with a trend toward mesial-to-distal reduction in the molar row area accompanied by allometric changes. Our findings also show the limitations of the IC model for explaining molar proportions in primates, particularly the variation in the relative size at the interspecific scale in the hominid lineage.</p>\",\"PeriodicalId\":13666,\"journal\":{\"name\":\"Integrative Organismal Biology\",\"volume\":\"6 1\",\"pages\":\"obae041\"},\"PeriodicalIF\":2.2000,\"publicationDate\":\"2024-11-22\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11631436/pdf/\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Integrative Organismal Biology\",\"FirstCategoryId\":\"99\",\"ListUrlMain\":\"https://doi.org/10.1093/iob/obae041\",\"RegionNum\":4,\"RegionCategory\":\"生物学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"2024/1/1 0:00:00\",\"PubModel\":\"eCollection\",\"JCR\":\"Q2\",\"JCRName\":\"BIOLOGY\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Integrative Organismal Biology","FirstCategoryId":"99","ListUrlMain":"https://doi.org/10.1093/iob/obae041","RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"2024/1/1 0:00:00","PubModel":"eCollection","JCR":"Q2","JCRName":"BIOLOGY","Score":null,"Total":0}
Variation in Molar Size and Proportions in the Hominid Lineage: An Inter- and Intraspecific Approach.
The implications of the inhibitory cascade (IC) model in dental diversification have been primarily studied at an interspecific or higher level. In contrast, the study of organisms with recent evolutionary divergence or at an interpopulational scale is still very limited. Here, we assess the effect of changes in molar size and the ratio of local activators to inhibitors on molar proportions based on a compilation of data of crown diameters of the first, second, and third lower and upper molars of extinct and extant hominids and modern human populations. The analysis of allometric changes between the size of each tooth and the size of the molar row shows a negative allometry in first molars (M1), isometric changes in second molars (M2), and a positive allometry in third molars (M3) in both hominin phylogeny and modern human populations. On the other hand, the proportions of lower and upper molars of several hominid species fall outside the morphospace defined by the IC model, while most of the modern human populations fall within the morphospace defined by the model as M1 > M2 > M3. We conclude that there is a phylogenetic structuring for molar size, particularly in the maxilla, with a trend toward mesial-to-distal reduction in the molar row area accompanied by allometric changes. Our findings also show the limitations of the IC model for explaining molar proportions in primates, particularly the variation in the relative size at the interspecific scale in the hominid lineage.