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High lability of sexual system over 250 million years of evolution in morphologically conservative tadpole shrimps.
BMC Evol Biol 2013; 13:30BE

Abstract

BACKGROUND

Sexual system is a key factor affecting the genetic diversity, population structure, genome structure and the evolutionary potential of species. The sexual system androdioecy - where males and hermaphrodites coexist in populations - is extremely rare, yet is found in three crustacean groups, barnacles, a genus of clam shrimps Eulimnadia, and in the order Notostraca, the tadpole shrimps. In the ancient crustacean order Notostraca, high morphological conservatism contrasts with a wide diversity of sexual systems, including androdioecy. An understanding of the evolution of sexual systems in this group has been hampered by poor phylogenetic resolution and confounded by the widespread occurrence of cryptic species. Here we use a multigene supermatrix for 30 taxa to produce a comprehensive phylogenetic reconstruction of Notostraca. Based on this phylogenetic reconstruction we use character mapping techniques to investigate the evolution of sexual systems. We also tested the hypothesis that reproductive assurance has driven the evolution of androdioecy in Notostraca.

RESULTS

Character mapping analysis showed that sexual system is an extremely flexible trait within Notostraca, with repeated shifts between gonochorism and androdioecy, the latter having evolved a minimum of five times. In agreement with the reproductive assurance hypothesis androdioecious notostracans are found at significantly higher latitudes than gonochoric ones indicating that post glacial re-colonisation may have selected for the higher colonisation ability conferred by androdioecy.

CONCLUSIONS

In contrast to their conserved morphology, sexual system in Notostraca is highly labile and the rare reproductive mode androdioecy has evolved repeatedly within the order. Furthermore, we conclude that this lability of sexual system has been maintained for at least 250 million years and may have contributed to the long term evolutionary persistence of Notostraca. Our results further our understanding of the evolution of androdioecy and indicate that reproductive assurance is a recurrent theme involved in the evolution of this sexual system.

Authors+Show Affiliations

School of Biological, Biomedical and Environmental Sciences, University of Hull, Hull, HU6 7RX, UK. t.c.mathers@2006.hull.ac.ukNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

23384124

Citation

Mathers, Thomas C., et al. "High Lability of Sexual System Over 250 Million Years of Evolution in Morphologically Conservative Tadpole Shrimps." BMC Evolutionary Biology, vol. 13, 2013, p. 30.
Mathers TC, Hammond RL, Jenner RA, et al. High lability of sexual system over 250 million years of evolution in morphologically conservative tadpole shrimps. BMC Evol Biol. 2013;13:30.
Mathers, T. C., Hammond, R. L., Jenner, R. A., Zierold, T., Hänfling, B., & Gómez, A. (2013). High lability of sexual system over 250 million years of evolution in morphologically conservative tadpole shrimps. BMC Evolutionary Biology, 13, p. 30. doi:10.1186/1471-2148-13-30.
Mathers TC, et al. High Lability of Sexual System Over 250 Million Years of Evolution in Morphologically Conservative Tadpole Shrimps. BMC Evol Biol. 2013 Feb 5;13:30. PubMed PMID: 23384124.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - High lability of sexual system over 250 million years of evolution in morphologically conservative tadpole shrimps. AU - Mathers,Thomas C, AU - Hammond,Robert L, AU - Jenner,Ronald A, AU - Zierold,Thorid, AU - Hänfling,Bernd, AU - Gómez,Africa, Y1 - 2013/02/05/ PY - 2012/03/20/received PY - 2013/01/25/accepted PY - 2013/2/7/entrez PY - 2013/2/7/pubmed PY - 2013/6/1/medline SP - 30 EP - 30 JF - BMC evolutionary biology JO - BMC Evol. Biol. VL - 13 N2 - BACKGROUND: Sexual system is a key factor affecting the genetic diversity, population structure, genome structure and the evolutionary potential of species. The sexual system androdioecy - where males and hermaphrodites coexist in populations - is extremely rare, yet is found in three crustacean groups, barnacles, a genus of clam shrimps Eulimnadia, and in the order Notostraca, the tadpole shrimps. In the ancient crustacean order Notostraca, high morphological conservatism contrasts with a wide diversity of sexual systems, including androdioecy. An understanding of the evolution of sexual systems in this group has been hampered by poor phylogenetic resolution and confounded by the widespread occurrence of cryptic species. Here we use a multigene supermatrix for 30 taxa to produce a comprehensive phylogenetic reconstruction of Notostraca. Based on this phylogenetic reconstruction we use character mapping techniques to investigate the evolution of sexual systems. We also tested the hypothesis that reproductive assurance has driven the evolution of androdioecy in Notostraca. RESULTS: Character mapping analysis showed that sexual system is an extremely flexible trait within Notostraca, with repeated shifts between gonochorism and androdioecy, the latter having evolved a minimum of five times. In agreement with the reproductive assurance hypothesis androdioecious notostracans are found at significantly higher latitudes than gonochoric ones indicating that post glacial re-colonisation may have selected for the higher colonisation ability conferred by androdioecy. CONCLUSIONS: In contrast to their conserved morphology, sexual system in Notostraca is highly labile and the rare reproductive mode androdioecy has evolved repeatedly within the order. Furthermore, we conclude that this lability of sexual system has been maintained for at least 250 million years and may have contributed to the long term evolutionary persistence of Notostraca. Our results further our understanding of the evolution of androdioecy and indicate that reproductive assurance is a recurrent theme involved in the evolution of this sexual system. SN - 1471-2148 UR - https://www.unboundmedicine.com/medline/citation/23384124/High_lability_of_sexual_system_over_250_million_years_of_evolution_in_morphologically_conservative_tadpole_shrimps_ L2 - https://bmcevolbiol.biomedcentral.com/articles/10.1186/1471-2148-13-30 DB - PRIME DP - Unbound Medicine ER -