Molecular evidence suggests an ancient radiation for the fairy shrimp genus Streptocephalus (Branchiopoda: Anostraca)
In: Biological Journal of the Linnean Society. Academic Press: London; New York. ISSN 0024-4066; e-ISSN 1095-8312, meer
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| Trefwoord |
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| Author keywords |
biogeography, freshwater crustaceans, mitochondrial and nuclear DNA |
| Auteurs | | Top |
- Daniels, S.R.
- Hamer, M.
- Rogers, C.
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| Abstract |
Phylogenetic relationships among assumed Gondwanan aquatic inland invertebrate fauna are generally largely neglected, and biogeographical hypotheses for these organisms are generally inferred from historic (palaeogeographical) and contemporary distribution patterns. The distribution of the monogeneric thermophilic freshwater fairy shrimp family Streptocephalidae (Streptocephalus) provides a particularly useful framework to test the three contrasting biogeographical scenarios proposed for the evolution of this group: (1) the genus evolved in Laurasia and subsequently dispersed into Africa and North America; (2) the genus evolved and dispersed out of Africa and (3) the current distribution of the genus is the result of vicariance following the fragmentation of Gondwana. In the present study, the phylogenetic relationships of species in this genus are examined with the use of two mitochondrial genes (12S rRNA and COI mtDNA), while the phylogenetic relationships among the North American species and selected African taxa was investigated using the nuclear fragment (5.8S-ITS-1-18S). Phylogenetic results indicate that Streptocephalus probably evolved in Gondwana and that the current distribution patterns are a consequence of a combination of vicariance and limited dispersal. The implications for the evolution of continental freshwater crustaceans are discussed. |
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