Skip to main content
    • Aa
    • Aa

Sexual shape dimorphism and selection pressure on males in fossil ostracodes

  • Tatsuhiko Yamaguchi (a1), Rie Honda (a2), Hiroki Matsui (a3) and Hiroshi Nishi (a4)

Sexual dimorphism is thought to have evolved via selection on both sexes. Ostracodes display sexual shape dimorphism in adult valves; however, no previous studies have addressed temporal changes on evolutionary timescales or examined the relationships between sexual shape dimorphism and selection pressure and between sexual shape dimorphism and juvenile shape. Temporal changes in sexually dimorphic traits result from responses of these traits to selection pressure. Using the Gaussian mixture model for the height/length ratio, a valve-shape parameter, we identified sexual differences in the valve shape of Krithe dolichodeira s.l. from deep-sea sediments of the Paleocene (62.6–57.6 Ma) and estimated the proportion of females in the fossil populations at 11 time intervals. Because the proportion of females in a population is altered by the mortality rate of adult males, it is reflective of selection pressure on males. We attempted to correlate the height/length ratios between the sexes with the proportion of females, taking into consideration that the valve shape was not linked with the selection pressure on males. In time-series data of the height/length ratio, both sexes indicate no significant changes on evolutionary timescales, even though the sex ratio of the population changed from female skewed to male skewed during the late Paleocene. The sexual shape dimorphism was not driven by sexual selection. The static allometry between the height/length ratio and length indicates that the sexual shape dimorphism did not function for sexual display. The absence of change over time in the female allometric slope suggests that the evolution of valve shape was constrained by stasis.

Linked references
Hide All

This list contains references from the content that can be linked to their source. For a full set of references and notes please see the PDF or HTML where available.

K. Abe 1990. What the sex ratios tells us: a case from marine ostracods. Pp. 175185 in R. Whatley, and C. Maybury, eds. Ostracoda and global events. Chapman and Hall, London.

D. R. Anderson , K. P. Burnham , and W. L. Thompson . 2000. Null hypothesis testing: problems, prevalence, and an alternative. Journal of Wildlife Management 64:912923.

M. Ayress , T. Barrows , V. Passlow , and R. Whatley . 1999. Neogene to Recent species of Krithe (Crustacea: Ostracoda) from the Tasman Sea and off Southern Australia with description of five new species. Records of the Australian Museum 51:122.

A. V. Badyaev , and T. E. Martin . 2000. Sexual dimorphism in relation to current selection in the house finch. Evolution 54:987997.

A. V. Badyaev , L. A. Whittingham , and G. E. Hill . 2001. The evolution of sexual size dimorphism in the house finch. III. Developmental basis. Evolution 55:176189.

R. Bonduriansky 2007. Sexual selection and allometry: a critical reappraisal of the evidence and ideas. Evolution 61:838849.

R. Bonduriansky , and T. Day . 2003. The evolution of static allometry in sexually selected traits. Evolution 57:24502458.

G. Celeux , and G. Govaert . 1995. Gaussian parsimonious clustering models. Pattern Recognition 28:781793.

A. C. Cohen , and J. G. Morin . 1990. Patterns of reproduction in ostracodes: a review. Journal of Crustacean Biology 10:184211.

D. L. Danielopol , A. Baltanás , T. Namiotko , W. Geiger , M. Pichler , M. Reina , and G. Roidmayr . 2008. Developmental trajectories in geographically separated populations of non-marine ostracods: morphometric applications for palaeoecological studies. Senckenbergiana lethaea 88:183193.

C. K. Egset , T. F. Hansen , A. Le Rouzic , G. H. Bolstad , G. Rosenqvist , and C. Pélabon . 2012. Artificial selection on allometry: change in elevation but not slope. Journal of Evolutionary Biology 25:938948.

S. T. Emlen , and L. W. Oring . 1977. Ecology, sexual selection, and the evolution of mating systems. Science 197:215223.

C. Firmat , I. Lozano-Fernández , J. Agustí , G. Bolstad , G. Cuenca-Bescós , T. Hansen , and C. Pélabon . 2014. Walk the line: 600 000 years of molar evolution constrained by allometry in the fossil rodent Mimomys savini . Philosophical Transactions of the Royal Society B 369:20140057.

M.-B. Forel , S. Crasquin , A. Chitnarin , L. Angiolini , and M. Gaetani . 2015. Precocious sexual dimorphism and the Lilliput effect in Neo-Tethyan Ostracoda (Crustacea) through the Permian–Triassic boundary. Palaeontology 58:409454.

A. J. Green 1992. Positive allometry is likely with mate choice, competitive display and other functions. Animal Behaviour 43:170172.

F. M. Gradstein , J. G. Ogg , M. D. Schmitz , and G. M. Ogg . 2012. The Geological Time Scale 2012. Elsevier, Boston.

D. J. Horne , A. Cohen , and K. Martens . 2002. Taxonomy, morphology and biology of Quaternary and living Ostracoda. Pp. 536. in J. A. Holmes, and Allan R. Chivas, eds. The Ostracoda: applications in Quaternary research. American Geophysical Union, Washington, D.C.

G. Hunt 2004a. Phenotypic variance in fossil samples: modeling the consequences of time-averaging. Paleobiology 30:426443.

G. Hunt 2004b. Phenotypic variance inflation in fossil samples: an empirical assessment. Paleobiology 30:487506.

G. Hunt 2006. Fitting and comparing models of phyletic evolution: random walks and beyond. Paleobiology 32:578601.

G. Hunt 2007a. Evolutionary divergence in directions of high phenotypic variance in the ostracode genus Poseidonamicus . Evolution 61:15601576.

G. Hunt 2007b. The relative importance of directional change, random walks, and stasis in the evolution of fossil lineages. Proceedings of the National Academy of Sciences USA 104:1840418408.

G. Hunt 2013. Testing the link between phenotypic evolution and speciation: an integrated palaeontological and phylogenetic analysis. Methods in Ecology and Evolution 4:714723.

G. Hunt , and R. E. Chapman . 2001. Evaluating hypotheses of instar-grouping in arthropods: a maximum likelihood approach. Paleobiology 27:466484.

G. Hunt , and D. L. Rabosky . 2014. Phenotypic evolution in fossil species: pattern and process. Annual Review of Earth and Planetary Sciences 42:421441.

G. Hunt , and K. Roy . 2006. Climate change, body size evolution, and Cope’s Rule in deep-sea ostracodes. Proceedings of the National Academy of Sciences USA 103:13471352.

G. Hunt , M. A. Bell , and M. P. Travis . 2008. Evolution toward a new adaptive optimum: phenotypic evolution in a fossil stickleback lineage. Evolution 62:700710.

G. Hunt , S. A. Wicaksono , J. E. Brown , and K. G. MacLeod . 2010. Climate-driven body-size trends in the ostracode fauna of the deep Indian Ocean. Palaeontology 53:12551268.

G. Hunt , M. J. Hopkins , and S. Lidgard . 2015. Simple versus complex models of trait evolution and stasis as a response to environmental change. Proceedings of the National Academy of Sciences USA 112:48854890.

R. J. Knell , D. Naish , J. L. Tomkins , and D. W. E. Hone . 2013. Sexual selection in prehistoric animals: detection and implications. Trends in Ecology and Evolution 28:3847.

R. Lande 1980. Sexual dimorphism, sexual selection, and adaptation in polygenic characters. Evolution 34:292305.

M. J. F. Martins , J. Vandekerkhove , F. Mezquita , O. Schmit , J. Rueda , T. Namiotko , and G. Rossetti . 2009. Dynamics of sexual and parthenogenetic populations of Eucypris virens (Crustacea: Ostracoda) in three temporary ponds. Hydrobiologia 636:219232.

R. Matzke-Karasz , R. J. Smith , R. Symonova , C. G. Miller , and P. Tafforeau . 2009. Sexual intercourse involving giant sperm in Cretaceous ostracode. Science 324:1535.

R. Motani , D. Jiang , O. Rieppel , Y. Xue , and A. Tintori . 2015. Adult sex ratio, sexual dimorphism and sexual selection in a Mesozoic reptile. Proceedings of the Royal Society B 282:20151658.

K. Padian , and J. R. Horner . 2013. Misconceptions of sexual selection and species recognition: a response to Knell et al. and to Mendelson and Shaw. Trends in Ecology and Evolution 28:249250.

C. Pélabon , C. Firmat , G. H. Bolstad , K. L. Voje , D. Houle , J. Cassara , A. Le Rouzic , and T. F. Hansen . 2014. Evolution of morphological allometry. Annals of the New York Academy of Sciences 1320:5875.

M. Petrie 1992. Are all secondary sexual display structures positively allometric and, if so, why? Animal Behaviour 43:173175.

R. A. Reyment 1985. Phenotypic evolution in a lineage of the Eocene ostracod Echinocythereis . Paleobiology 11:174194.

V. Rossi , and P. Menozzi . 2012. Inbreeding and outbreeding depression in geographical parthenogens Heterocypris incongruens and Eucypris virens (Crustacea: Ostracoda). Italian Journal of Zoology 79:559567.

V. Rossi , M. Bartoli , C. Bellavere , A. Gandolfi , E. Salvador , and P. Menozzi . 2004. Heterocypris (Crustacea: Ostracoda) from the Isole Pelagie (Sicily, Italy): Hatching phenology of resting eggs. Italian Journal of Zoology 71:223231.

V. Rossi , A. Martorella , and P. Menozzi . 2013. Hatching phenology and voltinism of Heterocypris barbara (Crustacea: Ostracoda) from Lampedusa (Sicily, Italy). Journal of Limnology 72:227237.

M. Saito-Kato , Y. Tanimura , S. Mori , and M. Julius . 2015. Morphological evolution of Stephanodiscus (Bacillariophyta) in Lake Biwa from a 300 ka fossil record. Journal of Micropalaeontology 34:165179.

G. Schwarz 1978. Estimating the dimension of a model. Annals of Statistics 6:461464.

D. J. Siveter , G. Tanaka , U. C. Farrell , M. J. Martin , D. J. Siveter , and D. E. G. Briggs . 2014. Exceptionally preserved 450-million-year-old Ordovician ostracods with brood care. Current Biology 24:801806.

H. D. Sheets , and C. E. Mitchell . 2001. Uncorrected change produces the apparent dependence of evolutionary rate on interval. Paleobiology 27:207210.

A. M. Siepielski , J. D. DiBattista , and S. M. Carlson . 2009. It’s about time: the temporal dynamics of phenotypic selection in the wild. Ecology Letters 12:12611276.

T. Székely , A. Liker , R. P. Freckleton , C. Fichtel , and P. M. Kappeler . 2014. Sex-biased survival predicts adult sex ratio variation in wild birds. Proceedings of the Royal Society B 281:20140342.

G. Tanaka 2016. Redescription of two krithid species (Crustacea, Ostracoda) from the Sea of Japan, with a comment on the taxonomic characters of Krithidae. Paleontological Research 20:3147.

J. Vandekerkhove , R. Matzke-Karasz , F. Mezquita , and G. Rossetti . 2007. Experimental assessment of the fecundity of Eucypris virens (Ostracoda, Crustacea) under natural sex ratios. Freshwater Biology 52:10581064.

K. L. Voje , T. F. Hansen , C. K. Egset , G. H. Bolstad , and C. Pélabon . 2014. Allometric constraints and the evolution of allometry. Evolution 68:866885.

T. Yamaguchi , H. Matsui , and H. Nishi . 2017a. Taxonomy of Maastrichtian–Thanetian deep-sea ostracodes from U1407, IODP Exp 342, off Newfoundland, Northwestern Atlantic. Part 1: Families Cytherellidae, Bairdiidae, Pontocyprididae, Bythocytheridae, and Cytheruridae. Paleontological Research 21:122.

Recommend this journal

Email your librarian or administrator to recommend adding this journal to your organisation's collection.

  • ISSN: 0094-8373
  • EISSN: 1938-5331
  • URL: /core/journals/paleobiology
Please enter your name
Please enter a valid email address
Who would you like to send this to? *


Full text views

Total number of HTML views: 4
Total number of PDF views: 25 *
Loading metrics...

Abstract views

Total abstract views: 186 *
Loading metrics...

* Views captured on Cambridge Core between 22nd May 2017 - 25th July 2017. This data will be updated every 24 hours.