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Cryptic speciation or global spread? The case of a cosmopolitan marine invertebrate with limited dispersal capabilities.

R PP, V A, M R, X T - Sci Rep (2013)

Bottom Line: The existence of globally-distributed species with low dispersal capabilities is a paradox that has been explained as a result of human-mediated transport and by hidden diversity in the form of unrecognized cryptic species.In addition, we found a complex geographic structure and multiple clades occurred in sympatry.The present study shows the complexity of discerning the role of cryptic diversity from human-driven range shifts worldwide, as well as disentangling the effects of natural and artificial dispersal.

View Article: PubMed Central - PubMed

Affiliation: Center for Advanced Studies of Blanes (CEAB-CSIC), Accés Cala S Francesc 14, 17300 Blanes (Girona), Spain.

ABSTRACT
The existence of globally-distributed species with low dispersal capabilities is a paradox that has been explained as a result of human-mediated transport and by hidden diversity in the form of unrecognized cryptic species. Both factors are not mutually exclusive, but relatively few studies have demonstrated the presence of both. Here we analyse the genetic patterns of the colonial ascidian Diplosoma listerianum, a species nowadays distributed globally. The study of a fragment of a mitochondrial gene in localities worldwide revealed the existence of multiple cryptic species. In addition, we found a complex geographic structure and multiple clades occurred in sympatry. One of the species showed strong population structure irrespective of geographical distances, which is coherent with stochastic dispersal linked to human transport. The present study shows the complexity of discerning the role of cryptic diversity from human-driven range shifts worldwide, as well as disentangling the effects of natural and artificial dispersal.

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Phylogenetic tree.BI consensus tree of haplotypes of D. listerianum. Four main clades, (A) (and subclade A.1), (B), (C) and (D) are highlighted. For inter-calde relationships and for the internal arrangement within clade A, as there were differences among the three methods, the BI topology (and associated posterior probabilities) is shown. Branches retrieved by the three methods are indicated by three support values on the nodes. Values represent posterior probabilities for BI when >0.5, and bootstrap supports when >50% for ML and MP analyses, in that order. A sequence of Diplosoma spongiforme (Acc. number AY600972.1) was included as an outgroup.
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f2: Phylogenetic tree.BI consensus tree of haplotypes of D. listerianum. Four main clades, (A) (and subclade A.1), (B), (C) and (D) are highlighted. For inter-calde relationships and for the internal arrangement within clade A, as there were differences among the three methods, the BI topology (and associated posterior probabilities) is shown. Branches retrieved by the three methods are indicated by three support values on the nodes. Values represent posterior probabilities for BI when >0.5, and bootstrap supports when >50% for ML and MP analyses, in that order. A sequence of Diplosoma spongiforme (Acc. number AY600972.1) was included as an outgroup.

Mentions: Phylogenetic trees reconstructed based on Bayesian Inference (BI), Maximum Likelihood (ML), and Maximum Parsimony (MP) criteria grouped the COI haplotypes of Diplosoma listerianum into four well supported monophyletic clades (posterior probabilities of 1.00, bootstrap values ≥90%) henceforth named clades A, B, C and D (Fig. 2). Interclade genetic divergence ranged from a 17% between clades A and D to a 20% between clades C and B, and C and A (see Table 2), and intraclade variability was always comparatively lower (0.2%–7.3%). However, the phylogenetic relationships among clades could not be completely resolved with this gene fragment (see Fig. 2), as reflected by overall low support and some unstable between-clade relationships depending on the reconstruction method. Likewise, relationships within the major clade (A) were not clearly defined and varied according to the method used, although a subclade A.1, grouping 8 haplotypes, appeared in all cases with strong support (posterior probability of 1, bootstrap values of 100%, Fig. 2).


Cryptic speciation or global spread? The case of a cosmopolitan marine invertebrate with limited dispersal capabilities.

R PP, V A, M R, X T - Sci Rep (2013)

Phylogenetic tree.BI consensus tree of haplotypes of D. listerianum. Four main clades, (A) (and subclade A.1), (B), (C) and (D) are highlighted. For inter-calde relationships and for the internal arrangement within clade A, as there were differences among the three methods, the BI topology (and associated posterior probabilities) is shown. Branches retrieved by the three methods are indicated by three support values on the nodes. Values represent posterior probabilities for BI when >0.5, and bootstrap supports when >50% for ML and MP analyses, in that order. A sequence of Diplosoma spongiforme (Acc. number AY600972.1) was included as an outgroup.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3824166&req=5

f2: Phylogenetic tree.BI consensus tree of haplotypes of D. listerianum. Four main clades, (A) (and subclade A.1), (B), (C) and (D) are highlighted. For inter-calde relationships and for the internal arrangement within clade A, as there were differences among the three methods, the BI topology (and associated posterior probabilities) is shown. Branches retrieved by the three methods are indicated by three support values on the nodes. Values represent posterior probabilities for BI when >0.5, and bootstrap supports when >50% for ML and MP analyses, in that order. A sequence of Diplosoma spongiforme (Acc. number AY600972.1) was included as an outgroup.
Mentions: Phylogenetic trees reconstructed based on Bayesian Inference (BI), Maximum Likelihood (ML), and Maximum Parsimony (MP) criteria grouped the COI haplotypes of Diplosoma listerianum into four well supported monophyletic clades (posterior probabilities of 1.00, bootstrap values ≥90%) henceforth named clades A, B, C and D (Fig. 2). Interclade genetic divergence ranged from a 17% between clades A and D to a 20% between clades C and B, and C and A (see Table 2), and intraclade variability was always comparatively lower (0.2%–7.3%). However, the phylogenetic relationships among clades could not be completely resolved with this gene fragment (see Fig. 2), as reflected by overall low support and some unstable between-clade relationships depending on the reconstruction method. Likewise, relationships within the major clade (A) were not clearly defined and varied according to the method used, although a subclade A.1, grouping 8 haplotypes, appeared in all cases with strong support (posterior probability of 1, bootstrap values of 100%, Fig. 2).

Bottom Line: The existence of globally-distributed species with low dispersal capabilities is a paradox that has been explained as a result of human-mediated transport and by hidden diversity in the form of unrecognized cryptic species.In addition, we found a complex geographic structure and multiple clades occurred in sympatry.The present study shows the complexity of discerning the role of cryptic diversity from human-driven range shifts worldwide, as well as disentangling the effects of natural and artificial dispersal.

View Article: PubMed Central - PubMed

Affiliation: Center for Advanced Studies of Blanes (CEAB-CSIC), Accés Cala S Francesc 14, 17300 Blanes (Girona), Spain.

ABSTRACT
The existence of globally-distributed species with low dispersal capabilities is a paradox that has been explained as a result of human-mediated transport and by hidden diversity in the form of unrecognized cryptic species. Both factors are not mutually exclusive, but relatively few studies have demonstrated the presence of both. Here we analyse the genetic patterns of the colonial ascidian Diplosoma listerianum, a species nowadays distributed globally. The study of a fragment of a mitochondrial gene in localities worldwide revealed the existence of multiple cryptic species. In addition, we found a complex geographic structure and multiple clades occurred in sympatry. One of the species showed strong population structure irrespective of geographical distances, which is coherent with stochastic dispersal linked to human transport. The present study shows the complexity of discerning the role of cryptic diversity from human-driven range shifts worldwide, as well as disentangling the effects of natural and artificial dispersal.

Show MeSH