Ontogenetic mechanisms underlying sexual size dimorphism in Urodele amphibians: An across-species approach
Why do two sexes of the same species differ in body size holds a long-standing question of evolutionary biology. While many across-species comparisons have focused on ultimate causes behind sexual size dimorphism (SSD), only have a few been directed toward elucidating its ontogenetic basis. Urodeles...
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| Format: | Article |
| Language: | English |
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Oxford University Press
2013-02-01
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| Series: | Current Zoology |
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| Online Access: | http://www.currentzoology.org/paperdetail.asp?id=12193 |
| _version_ | 1818517132572360704 |
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| author | Lixia ZHANG, Xin LU |
| author_facet | Lixia ZHANG, Xin LU |
| author_sort | Lixia ZHANG, Xin LU |
| collection | DOAJ |
| description | Why do two sexes of the same species differ in body size holds a long-standing question of evolutionary biology. While many across-species comparisons have focused on ultimate causes behind sexual size dimorphism (SSD), only have a few been directed toward elucidating its ontogenetic basis. Urodeles are an amphibian group in which the direction and degree of SSD vary greatly among species. Using demographic data yielded by skeletochronology for 33 urodele species, the current study reveals a positive across-species correlation between SSD and the sex difference in mean age of adult animals, and the latter increases with the corresponding difference in age at maturity; annual growth rate does not differ between the sexes. We conclude that extended longevities in one sex, which is mediated by delayed maturation, would allow it to grow for longer and get larger, with growth rate making a weak contribution to body size. The sex-specific divergence in ontogenetic trajectory might be explained by potentially high growth costs of reproduction to females in association with stronger fecundity selection, and to males that are expected to experience stronger sexual selection [Current Zoology 59 (1): 142–150, 2013]. |
| first_indexed | 2024-12-11T00:52:05Z |
| format | Article |
| id | doaj.art-9298ec759ae84eb89f7484ffabea587c |
| institution | Directory Open Access Journal |
| issn | 1674-5507 |
| language | English |
| last_indexed | 2024-12-11T00:52:05Z |
| publishDate | 2013-02-01 |
| publisher | Oxford University Press |
| record_format | Article |
| series | Current Zoology |
| spelling | doaj.art-9298ec759ae84eb89f7484ffabea587c2022-12-22T01:26:35ZengOxford University PressCurrent Zoology1674-55072013-02-01591142150Ontogenetic mechanisms underlying sexual size dimorphism in Urodele amphibians: An across-species approachLixia ZHANG, Xin LUWhy do two sexes of the same species differ in body size holds a long-standing question of evolutionary biology. While many across-species comparisons have focused on ultimate causes behind sexual size dimorphism (SSD), only have a few been directed toward elucidating its ontogenetic basis. Urodeles are an amphibian group in which the direction and degree of SSD vary greatly among species. Using demographic data yielded by skeletochronology for 33 urodele species, the current study reveals a positive across-species correlation between SSD and the sex difference in mean age of adult animals, and the latter increases with the corresponding difference in age at maturity; annual growth rate does not differ between the sexes. We conclude that extended longevities in one sex, which is mediated by delayed maturation, would allow it to grow for longer and get larger, with growth rate making a weak contribution to body size. The sex-specific divergence in ontogenetic trajectory might be explained by potentially high growth costs of reproduction to females in association with stronger fecundity selection, and to males that are expected to experience stronger sexual selection [Current Zoology 59 (1): 142–150, 2013].http://www.currentzoology.org/paperdetail.asp?id=12193EvolutionGrowth strategyLife historyPhylogenetic comparisonSexual size dimorphismUrodele amphibian |
| spellingShingle | Lixia ZHANG, Xin LU Ontogenetic mechanisms underlying sexual size dimorphism in Urodele amphibians: An across-species approach Current Zoology Evolution Growth strategy Life history Phylogenetic comparison Sexual size dimorphism Urodele amphibian |
| title | Ontogenetic mechanisms underlying sexual size dimorphism in Urodele amphibians: An across-species approach |
| title_full | Ontogenetic mechanisms underlying sexual size dimorphism in Urodele amphibians: An across-species approach |
| title_fullStr | Ontogenetic mechanisms underlying sexual size dimorphism in Urodele amphibians: An across-species approach |
| title_full_unstemmed | Ontogenetic mechanisms underlying sexual size dimorphism in Urodele amphibians: An across-species approach |
| title_short | Ontogenetic mechanisms underlying sexual size dimorphism in Urodele amphibians: An across-species approach |
| title_sort | ontogenetic mechanisms underlying sexual size dimorphism in urodele amphibians an across species approach |
| topic | Evolution Growth strategy Life history Phylogenetic comparison Sexual size dimorphism Urodele amphibian |
| url | http://www.currentzoology.org/paperdetail.asp?id=12193 |
| work_keys_str_mv | AT lixiazhangxinlu ontogeneticmechanismsunderlyingsexualsizedimorphisminurodeleamphibiansanacrossspeciesapproach |