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Progressive migration and anagenesis in Drimys confertifolia of the Juan Fernández Archipelago, Chile.

López-Sepúlveda P, Takayama K, Greimler J, Crawford DJ, Peñailillo P, Baeza M, Ruiz E, Kohl G, Tremetsberger K, Gatica A, Letelier L, Novoa P, Novak J, Stuessy TF - J. Plant Res. (2014)

Bottom Line: A common mode of speciation in oceanic islands is by anagenesis, wherein an immigrant arrives and through time transforms by mutation, recombination, and drift into a morphologically and genetically distinct species, with the new species accumulating a high level of genetic diversity.Drimys confertifolia shows a wide genetic variation within populations on both islands, and values of genetic diversity within populations are similar to those found within populations of the continental progenitor.The genetic results are compatible with the hypothesis of high levels of genetic variation accumulating within anagenetically derived species in oceanic islands, and with the concept of little or no geographical partitioning of this variation over the landscape.

View Article: PubMed Central - PubMed

Affiliation: Departamento de Botánica, Universidad de Concepción, Casilla 160-C, Concepción, Chile.

ABSTRACT
A common mode of speciation in oceanic islands is by anagenesis, wherein an immigrant arrives and through time transforms by mutation, recombination, and drift into a morphologically and genetically distinct species, with the new species accumulating a high level of genetic diversity. We investigate speciation in Drimys confertifolia, endemic to the two major islands of the Juan Fernández Archipelago, Chile, to determine genetic consequences of anagenesis, to examine relationships among populations of D. confertifolia and the continental species D. winteri and D. andina, and to test probable migration routes between the major islands. Population genetic analyses were conducted using AFLPs and nuclear microsatellites of 421 individuals from 42 populations from the Juan Fernández islands and the continent. Drimys confertifolia shows a wide genetic variation within populations on both islands, and values of genetic diversity within populations are similar to those found within populations of the continental progenitor. The genetic results are compatible with the hypothesis of high levels of genetic variation accumulating within anagenetically derived species in oceanic islands, and with the concept of little or no geographical partitioning of this variation over the landscape. Analysis of the probability of migration within the archipelago confirms colonization from the older island, Robinson Crusoe, to the younger island Alejandro Selkirk.

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Related in: MedlinePlus

Genetic relationships among populations of Drimys. SplitsTree NeighbourNet (phylogenetic network) of AFLP data showing relationships among individuals of D. andina, D. confertifolia, D. winteri var. chilensis and D. winteri var. andina (a), and Neighbour-Joining tree based on microsatellites showing relationships among populations in the same species of Drimys (b)
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Fig3: Genetic relationships among populations of Drimys. SplitsTree NeighbourNet (phylogenetic network) of AFLP data showing relationships among individuals of D. andina, D. confertifolia, D. winteri var. chilensis and D. winteri var. andina (a), and Neighbour-Joining tree based on microsatellites showing relationships among populations in the same species of Drimys (b)

Mentions: The NeighbourNet tree based on AFLP data using all individuals of D. confertifolia, D. andina, and D. winteri is shown in Fig. 3a. A separation between species is observed with D. confertifolia forming two groups, the first clearly differentiated and corresponding to Alejandro Selkirk Island, and the second to the populations of Robinson Crusoe Island. No clear separation between populations is visible, with only a weak divergence of populations 23, 30, 31 on Alejandro Selkirk Island and population 13 on Robinson Crusoe Island. The cluster of D. winteri does not show a separation between variety winteri and var. chilensis. No geographical partitioning is observed in all species.Fig. 3


Progressive migration and anagenesis in Drimys confertifolia of the Juan Fernández Archipelago, Chile.

López-Sepúlveda P, Takayama K, Greimler J, Crawford DJ, Peñailillo P, Baeza M, Ruiz E, Kohl G, Tremetsberger K, Gatica A, Letelier L, Novoa P, Novak J, Stuessy TF - J. Plant Res. (2014)

Genetic relationships among populations of Drimys. SplitsTree NeighbourNet (phylogenetic network) of AFLP data showing relationships among individuals of D. andina, D. confertifolia, D. winteri var. chilensis and D. winteri var. andina (a), and Neighbour-Joining tree based on microsatellites showing relationships among populations in the same species of Drimys (b)
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4300435&req=5

Fig3: Genetic relationships among populations of Drimys. SplitsTree NeighbourNet (phylogenetic network) of AFLP data showing relationships among individuals of D. andina, D. confertifolia, D. winteri var. chilensis and D. winteri var. andina (a), and Neighbour-Joining tree based on microsatellites showing relationships among populations in the same species of Drimys (b)
Mentions: The NeighbourNet tree based on AFLP data using all individuals of D. confertifolia, D. andina, and D. winteri is shown in Fig. 3a. A separation between species is observed with D. confertifolia forming two groups, the first clearly differentiated and corresponding to Alejandro Selkirk Island, and the second to the populations of Robinson Crusoe Island. No clear separation between populations is visible, with only a weak divergence of populations 23, 30, 31 on Alejandro Selkirk Island and population 13 on Robinson Crusoe Island. The cluster of D. winteri does not show a separation between variety winteri and var. chilensis. No geographical partitioning is observed in all species.Fig. 3

Bottom Line: A common mode of speciation in oceanic islands is by anagenesis, wherein an immigrant arrives and through time transforms by mutation, recombination, and drift into a morphologically and genetically distinct species, with the new species accumulating a high level of genetic diversity.Drimys confertifolia shows a wide genetic variation within populations on both islands, and values of genetic diversity within populations are similar to those found within populations of the continental progenitor.The genetic results are compatible with the hypothesis of high levels of genetic variation accumulating within anagenetically derived species in oceanic islands, and with the concept of little or no geographical partitioning of this variation over the landscape.

View Article: PubMed Central - PubMed

Affiliation: Departamento de Botánica, Universidad de Concepción, Casilla 160-C, Concepción, Chile.

ABSTRACT
A common mode of speciation in oceanic islands is by anagenesis, wherein an immigrant arrives and through time transforms by mutation, recombination, and drift into a morphologically and genetically distinct species, with the new species accumulating a high level of genetic diversity. We investigate speciation in Drimys confertifolia, endemic to the two major islands of the Juan Fernández Archipelago, Chile, to determine genetic consequences of anagenesis, to examine relationships among populations of D. confertifolia and the continental species D. winteri and D. andina, and to test probable migration routes between the major islands. Population genetic analyses were conducted using AFLPs and nuclear microsatellites of 421 individuals from 42 populations from the Juan Fernández islands and the continent. Drimys confertifolia shows a wide genetic variation within populations on both islands, and values of genetic diversity within populations are similar to those found within populations of the continental progenitor. The genetic results are compatible with the hypothesis of high levels of genetic variation accumulating within anagenetically derived species in oceanic islands, and with the concept of little or no geographical partitioning of this variation over the landscape. Analysis of the probability of migration within the archipelago confirms colonization from the older island, Robinson Crusoe, to the younger island Alejandro Selkirk.

Show MeSH
Related in: MedlinePlus