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Cryptic Speciation (cryptic + speciation)
Selected AbstractsPHYLOGEOGRAPHIC STRUCTURE AND CRYPTIC SPECIATION IN THE TRANS-ANTARCTIC MOSS PYRRHOBRYUM MNIOIDESEVOLUTION, Issue 2 2003Stuart F. McDaniel Abstract Many bryophyte species have distributions that span multiple continents. The hypotheses historically advanced to explain such distributions rely on either long-distance spore dispersal or slow rates of morphological evolution following ancient continental vicariance events. We use phylogenetic analyses of DNA sequence variation at three chloroplast loci (atpB-rbcL spacer, rps4 gene, and trnL intron and 3,spacer) to examine these two hypotheses in the trans-Antarctic moss Pyrrhobryum mnioides. We find: (1) reciprocal monophyly of Australasian and South American populations, indicating a lack of intercontinental dispersal; (2) shared haplotypes between Australia and New Zealand, suggesting recent or ongoing migration across the Tasman Sea; and (3) reciprocal monophyly among Patagonian and neotropical populations, suggesting no recent migration along the Andes. These results corroborate experimental work suggesting that spore features may be critical determinants of species range. We use the mid-Miocene development of the Atacama Desert, 14 million years ago, to calibrate a molecular clock for the tree. The age of the trans-Antarctic disjunction is estimated to be 80 million years ago, consistent with Gondwanan vicariance, making it among the most ancient documented cases of cryptic speciation. These data are in accord with niche conservatism, but whether the morphological stasis is a product of stabilizing selection or phylogenetic constraint is unknown. [source] Cryptic speciation and patterns of phenotypic variation of a highly variable acanthocephalan parasiteMOLECULAR ECOLOGY, Issue 19 2007M. L. STEINAUER Abstract An investigation of a parasite species that is broadly host- and habitat-specific and exhibits alternative transmission strategies was undertaken to examine intraspecific variability and if it can be attributed to cryptic speciation or environmentally induced plasticity. Specimens of an acanthocephalan parasite, Leptorhynchoides thecatus, collected throughout North America were analysed phylogenetically using sequences of the cytochrome oxidase I gene and the internal transcribed spacer region. Variation in host use, habitat use, and transmission were examined in a phylogenetic context to determine if they were more likely phylogenetically based or due to environmental influences. Results indicated that most of the variation detected can be explained by the presence of cryptic species. The majority of these species have narrow host and microhabitat specificities although one species, which also may comprise a complex of species, exhibits broad host and habitat specificity. Alternate transmission pathways only occurred in two of the cryptic species and correlate with host use patterns. Taxa that mature in piscivorous piscine hosts use a paratenic fish host to bridge the trophic gap between their amphipod intermediate host and piscivorous definitive host. One potential example of environmentally induced variation was identified in three populations of these parasites, which differ on their abilities to infect different host species. [source] PHYLOGEOGRAPHIC STRUCTURE AND CRYPTIC SPECIATION IN THE TRANS-ANTARCTIC MOSS PYRRHOBRYUM MNIOIDESEVOLUTION, Issue 2 2003Stuart F. McDaniel Abstract Many bryophyte species have distributions that span multiple continents. The hypotheses historically advanced to explain such distributions rely on either long-distance spore dispersal or slow rates of morphological evolution following ancient continental vicariance events. We use phylogenetic analyses of DNA sequence variation at three chloroplast loci (atpB-rbcL spacer, rps4 gene, and trnL intron and 3,spacer) to examine these two hypotheses in the trans-Antarctic moss Pyrrhobryum mnioides. We find: (1) reciprocal monophyly of Australasian and South American populations, indicating a lack of intercontinental dispersal; (2) shared haplotypes between Australia and New Zealand, suggesting recent or ongoing migration across the Tasman Sea; and (3) reciprocal monophyly among Patagonian and neotropical populations, suggesting no recent migration along the Andes. These results corroborate experimental work suggesting that spore features may be critical determinants of species range. We use the mid-Miocene development of the Atacama Desert, 14 million years ago, to calibrate a molecular clock for the tree. The age of the trans-Antarctic disjunction is estimated to be 80 million years ago, consistent with Gondwanan vicariance, making it among the most ancient documented cases of cryptic speciation. These data are in accord with niche conservatism, but whether the morphological stasis is a product of stabilizing selection or phylogenetic constraint is unknown. [source] Marine biogeography of southern Australia: phylogeographical structure in a temperate sea-starJOURNAL OF BIOGEOGRAPHY, Issue 12 2003Jonathan M. Waters Abstract Aim, To test whether marine biogeographical patterns observed at the community level are also important within species. It is postulated that historical hydrogeographic barriers have driven in situ diversification. Location, The intertidal and shallow subtidal zones of southern Australia, New Zealand and nearby islands. Australia's temperate marine communities are characterized by a high degree of endemism and show strong biogeographical structure along an east,west axis. Methods, Phylogeographical analysis of the widespread asteriid sea-star Coscinasterias muricata Verrill across southern Australia and New Zealand. Forty-two samples from 27 locations were included in phylogenetic analyses of mitochondrial (CO1; control region) and nuclear (ITS2) DNA sequences. Results, Analysis of mtDNA revealed a deep phylogenetic split within Australian C. muricata, strongly correlated with latitude. ,Northern' haplotypes (latitude , 37.6° S, nine sites, 15 samples) were 7.3,9.4% divergent from ,southern' haplotypes (latitude , 37.6° S, 19 sites, 27 samples), consistent with late Pliocene separation. Eastern and western representatives of the ,northern' clade were 0.5,1.0% divergent, probably reflecting Pleistocene isolation. The ,southern' clade of Australia is also represented in New Zealand, indicating Pleistocene oceanic dispersal. Nuclear DNA (ITS2) sequences yielded relatively little phylogenetic resolution, but were generally congruent with mtDNA-based groupings. Main conclusions, The phylogeographical pattern detected within Australian C. muricata closely resembles marine biogeographical groupings proposed on the basis of community and species distributions. Recurring evolutionary patterns may have been driven by the hydrographic history of southern Australia. Specifically, we suggest that Plio-Pleistocene temperature change and the repeated opening and closure of Bass Strait promoted allopatric divergence and perhaps cryptic speciation in C. muricata. [source] Three sisters in the same dress: cryptic speciation in African odonatesMOLECULAR ECOLOGY, Issue 18 2010A. CORDERO-RIVERA The discovery of cryptic species (i.e. two or more distinct but morphologically undistinguishable species) has grown exponentially in the last two decades, due mainly to the increasing availability of DNA sequences. This suggests that hidden in the known species, many of which have been described based solely on morphological information, there might be a high number of species waiting to be discovered. In this issue Damm et al. (2010) use a combination of genetic, morphological and ecological evidence to identify the first cryptic species complex found within dragonflies (insect order Odonata). Their findings add more evidence for the importance of combining information from different disciplines to new species' discovery (DeSalle et al. 2005). [source] Cryptic speciation and patterns of phenotypic variation of a highly variable acanthocephalan parasiteMOLECULAR ECOLOGY, Issue 19 2007M. L. STEINAUER Abstract An investigation of a parasite species that is broadly host- and habitat-specific and exhibits alternative transmission strategies was undertaken to examine intraspecific variability and if it can be attributed to cryptic speciation or environmentally induced plasticity. Specimens of an acanthocephalan parasite, Leptorhynchoides thecatus, collected throughout North America were analysed phylogenetically using sequences of the cytochrome oxidase I gene and the internal transcribed spacer region. Variation in host use, habitat use, and transmission were examined in a phylogenetic context to determine if they were more likely phylogenetically based or due to environmental influences. Results indicated that most of the variation detected can be explained by the presence of cryptic species. The majority of these species have narrow host and microhabitat specificities although one species, which also may comprise a complex of species, exhibits broad host and habitat specificity. Alternate transmission pathways only occurred in two of the cryptic species and correlate with host use patterns. Taxa that mature in piscivorous piscine hosts use a paratenic fish host to bridge the trophic gap between their amphipod intermediate host and piscivorous definitive host. One potential example of environmentally induced variation was identified in three populations of these parasites, which differ on their abilities to infect different host species. [source] Hybridization among cryptic species of the cellar fungus Coniophora puteana (Basidiomycota)MOLECULAR ECOLOGY, Issue 2 2007HÅVARD KAUSERUD Abstract In this study we have analysed the genetic variation and phylogeography in a global sample of the cellar fungus Coniophora puteana, which is an important destroyer of wooden materials indoor. Multilocus genealogies of three DNA regions (beta tubulin, nrDNA ITS and translation elongation factor 1,) revealed the occurrence of three cryptic species (PS1,3) in the morphotaxon C. puteana. One of the lineages (PS3) is apparently restricted to North America while the other two (PS1,2) have wider distributions on multiple continents. Interspecific hybridization has happened between two of the lineages (PS1 and PS3) in North America. In three dikaryotic isolates, two highly divergent beta tubulin alleles coexisted, one derived from PS1 and one from PS3. Furthermore, one isolate included a recombinant ITS sequence, where ITS1 resembled the ITS1 version of PS3 while ITS2 was identical to a frequent PS1 ITS2 version. This pattern must be due to hybridization succeeded by intralocus recombination in ITS. The results further indicated that introgression has happened between subgroups appearing in PS1. We hypothesize that the observed reticulate evolution is due to previous allopatric separation followed by more recent reoccurrence in sympatry, where barriers to gene flow have not yet evolved. A complex phylogeographical structure is observed in the morphotaxon C. puteana caused by (i) cryptic speciation; (ii) the interplay between natural migration and distribution patterns and probably more recent human mediated dispersal events; and (iii) hybridization and introgression. [source] Unravelling evolutionary lineages among South African velvet worms (Onychophora: Peripatopsis) provides evidence for widespread cryptic speciationBIOLOGICAL JOURNAL OF THE LINNEAN SOCIETY, Issue 1 2009SAVEL R. DANIELS The endemic South African velvet worm genus Peripatopsis currently contains eight recognized species described from variable morphological characters and the current taxonomy is unsatisfactory. In an attempt to investigate evolutionary relationships within Peripatopsis, we collected 137 individuals from 34 sample localities for six of the eight species. Sequence data derived from two partial mitochondrial (mt)DNA gene loci (COI and 12S rRNA), as well as partial sequence data from the ribosomal nuclear 18S rDNA locus in combination with gross morphological characters and scanning electron microscopy (SEM), was used to examine evolutionary relationships. Phylogenetic relationships were investigated using minimum evolution (ME) and Bayesian inferences (BI). Additionally, we also undertook a maximum likelihood (ML) analyses on the combined DNA sequence data set. The combined DNA evidence topologies derived from the ME, BI, and ML was highly congruent and was characterized by the presence of multiple lineages within recognized taxa. Peripatopsis clavigera, Peripatopsis moseleyi, and Peripatopsis sedgwicki each comprised two evolutionary lineages; Peripatopsis capensis comprised three; and Peripatopsis balfouri comprised six operational taxonomic units respectively. Genealogical exclusivity at both mtDNA and nuclear DNA among the geographically coherent groups coupled with pronounced sequence divergence suggested a two-fold increase in the number of species within Peripatopsis. Previously used gross morphological characters (such as the number of leg pairs and colour) were either highly variable within operational taxonomic units, or were invariant, suggesting that alternative morphological characters are necessary for species discrimination. SEM results revealed potentially useful diagnostic characters that can discriminate between at least discriminate some of the newly-identified lineages. © 2009 The Linnean Society of London, Biological Journal of the Linnean Society 2009, 97, 200,216. [source] | ||||||||||