Geographical distribution of cryptic genetic types in the planktonic foraminifer <i>Globigerinoides ruber</i>

Aurahs, Ralf; Grimm, Guido W.; Hemleben, Vera; Hemleben, Christoph; Kučera, Michal

doi:10.1111/j.1365-294x.2009.04136.x

Cited by 87 publications

(90 citation statements)

References 69 publications

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“…The second challenge is that a number of studies have presented molecular evidence that morphospecies generally contain multiple "cryptic" genotypes that correspond to distinct biological species (30,35,49). Whereas these findings lend further support to the argument that Foraminifera morphospecies are reproductively isolated (assumption i), the existence of cryptic biological species limits what can be inferred from morphospecies-level data.…”

Section: Evaluating Assumptionsmentioning

confidence: 40%

“…Analyses of small subunit ribosomal DNA (SSU rDNA) data for 19 extant morphospecies (of ∼50) indicate that morphospecies are generally monophyletic, and that ancestor-descendant relationships among morphospecies are accurately inferred from fossils at lower levels of the phylogeny (33,34). One noted exception to monophyly among extant morphospecies is Globigerinoides ruber, which is now recognized as comprising two distinct clades on the basis of molecular evidence (35). Inconsistencies between molecular and fossil data are largely confined to the placement of higher-order clades, where SSU rDNA divergences are high and relationships are difficult to resolve (36).…”

Section: Evaluating Assumptionsmentioning

confidence: 99%

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Assessing the role of cladogenesis in macroevolution by integrating fossil and molecular evidence

Strotz

Allen

2013

Proc. Natl. Acad. Sci. U.S.A.

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Assessing the extent to which population subdivision during cladogenesis is necessary for long-term phenotypic evolution is of fundamental importance in a broad range of biological disciplines. Differentiating cladogenesis from anagenesis, defined as evolution within a species, has generally been hampered by dating precision, insufficient fossil data, and difficulties in establishing a direct link between morphological changes detectable in the fossil record and biological species. Here we quantify the relative frequencies of cladogenesis and anagenesis for macroperforate planktic Foraminifera, which arguably have the most complete fossil record currently available, to address this question. Analyzing this record in light of molecular evidence, while taking into account the precision of fossil dating techniques, we estimate that the fraction of speciation events attributable to anagenesis is <19% during the Cenozoic era (last 65 Myr) and <10% during the Neogene period (last 23 Myr). Our central conclusion-that cladogenesis is the predominant mode by which new planktic Foraminifera taxa become established at macroevolutionary time scales-differs markedly from the conclusion reached in a recent study based solely on fossil data. These disparate findings demonstrate that interpretations of macroevolutionary dynamics in the fossil record can be fundamentally altered in light of genetic evidence. anagenesis, which occurs within a species, and cladogenesis, which occurs during speciation and results in the subdivision of a species into two reproductively isolated, independently evolving taxa (1, 2). Distinguishing between these modes is essential to determining the role of population subdivision in evolutionary dynamics (3,4). This topic has received considerable attention in paleontology (1, 2), perhaps because the fossil record provides the only direct record of long-term morphological change (5), but its importance extends to other biological disciplines. For example, in population genetics, models only predict that phenotypic change is contingent upon or associated with the evolution of reproductive isolation under specific circumstances (3). Thus, a primary role for cladogenesis may highlight the importance of particular speciation modes (2), metapopulations dynamics (6), or adaptive peaks in fitness landscapes (7,8). In community ecology, both evolutionary modes may influence biodiversity, but the mechanisms differ: only cladogenesis results in an increase in diversity (9-11), but anagenesis may help maintain diversity if it results in niche differences that facilitate species coexistence (12, 13).Remarkably few studies have attempted to quantify the relative frequencies of anagenesis and cladogenesis for entire species assemblages (e.g., refs. 5, 14, 15). Addressing this question is challenging due to insufficient fossil data for most taxa and the difficulties in relating morphological change to genetic divergence and the evolution of reproductive isolation (16). Fossil data can only be used to distinguish anag...

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Section: Evaluating Assumptionsmentioning

confidence: 40%

Section: Evaluating Assumptionsmentioning

confidence: 99%

Assessing the role of cladogenesis in macroevolution by integrating fossil and molecular evidence

Strotz

Allen

2013

Proc. Natl. Acad. Sci. U.S.A.

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“…Using the small subunit ribosomal RNA gene (SSU rDNA) as a marker, hidden genetic diversity was discovered within established morphospecies (Huber et al, 1997;de Vargas et al, 1999). This triggered a series of subsequent studies that screened morphospecies for their cryptic diversity (e.g., Darling et al, 1999;de Vargas et al, 1999;Aurahs et al, 2009a;Morard et al, 2009Morard et al, , 2011Weiner et al, 2012Weiner et al, , 2014André et al, 2013).…”

Section: Introductionmentioning

confidence: 99%

Methodology for Single-Cell Genetic Analysis of Planktonic Foraminifera for Studies of Protist Diversity and Evolution

et al. 2016

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Single-cell genetic analysis is an essential method to investigate the biodiversity and evolutionary ecology of marine protists. In protist groups that do not reproduce under laboratory conditions, this approach provides the only means to directly associate molecular sequences with cell morphology. The resulting unambiguous taxonomic identification of the DNA sequences is a prerequisite for barcoding and analyses of environmental metagenomic data. Extensive single-cell genetic studies have been carried out on planktonic foraminifera over the past 20 years to elucidate their phylogeny, cryptic diversity, biogeography, and the relationship between genetic and morphological variability. In the course of these investigations, it has become evident that genetic analysis at the individual specimen level is confronted by innumerable challenges ranging from the negligible amount of DNA present in the single cell to the substantial amount of DNA contamination introduced by endosymbionts or food particles. Consequently, a range of methods has been developed and applied throughout the years for the genetic analysis of planktonic foraminifera in order to enhance DNA amplification success rates. Yet, the description of these methods in the literature rarely occurred with equivalent levels of detail and the different approaches have never been compared in terms of their efficiency and reproducibility. Here, aiming at a standardization of methods, we provide a comprehensive review of all methods that have been employed for the single-cell genetic analysis of planktonic foraminifera. We compile data on success rates of DNA amplification and use these to evaluate the effects of key parameters associated with the methods of sample collection, storage and extraction of single-cell DNA. We show that the chosen methods influence the success rates of single-cell genetic studies, but the differences between them are not sufficient to hinder comparisons Weiner et al.Single-Cell Genetic Analysis of Foraminifera between studies carried out by different methods. The review thus not only provides a comprehensive reference with guidelines for future genetic studies on foraminifera, but it also establishes an important benchmark for investigations using existing single-cell datasets. The methods are widely applicable and the review may help to establish similar standard principles for their utilization in other protist groups.

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“…10) has lead to the paradigm that sympatric processes and/or genomic changes are the prevalent mode of speciation in planktonic marine microbial organisms (11)(12)(13)(14). On the other hand, based on the restricted geographic distributions of several cryptic species, it has been hypothesized that isolation by physical and/or ecological barriers is an important driver in allopatric processes, even in high dispersal marine microbes (15)(16)(17)(18).…”

mentioning

confidence: 99%

Limits to gene flow in a cosmopolitan marine planktonic diatom

Casteleyn

Leliaert

Backeljau

et al. 2010

Proc. Natl. Acad. Sci. U.S.A.

207

175

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The role of geographic isolation in marine microbial speciation is hotly debated because of the high dispersal potential and large population sizes of planktonic microorganisms and the apparent lack of strong dispersal barriers in the open sea. Here, we show that gene flow between distant populations of the globally distributed, bloom-forming diatom species Pseudo-nitzschia pungens (clade I) is limited and follows a strong isolation by distance pattern. Furthermore, phylogenetic analysis implies that under appropriate geographic and environmental circumstances, like the pronounced climatic changes in the Pleistocene, population structuring may lead to speciation and hence may play an important role in diversification of marine planktonic microorganisms. A better understanding of the factors that control population structuring is thus essential to reveal the role of allopatric speciation in marine microorganisms.allopatric speciation | dispersal | marine cosmopolitan planktonic microorganisms | population structure | microsatellites

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Geographical distribution of cryptic genetic types in the planktonic foraminifer Globigerinoides ruber

Cited by 87 publications

References 69 publications

Assessing the role of cladogenesis in macroevolution by integrating fossil and molecular evidence

Assessing the role of cladogenesis in macroevolution by integrating fossil and molecular evidence

Methodology for Single-Cell Genetic Analysis of Planktonic Foraminifera for Studies of Protist Diversity and Evolution

Limits to gene flow in a cosmopolitan marine planktonic diatom

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