02291nas a2200205   4500008004100000245010500041210007100146260001200217300001400229490000700243520160200250653001901852653001901871653001201890653001701902100001501919700001701934700001701951856011701968       2004                        eng d00aRevealing unknown or extinct lineages within Isoëtes (Isoëtaceae) using DNA sequences from hybrids0 aRevealing unknown or extinct lineages within Isoëtes Isoëtaceae   c2004///  a899 - 9040 v913 aIsoëtes, a heterosporous lycopod with a fossil record dating back to the Paleozoic, has numerous putative allopolyploids (resulting from hybridization events coupled with doubling of chromosome number). By using the highly variable nucleotide sequences from the second intron of a LFY homologue in Isoëtes, species could be delimited and hybrid origins determined. The data suggest that reticulate evolution is both common and complex within a more derived species complex of Isoëtes. Sequences of identifiable parentage and sequences that are unlike any diploid species known were recovered, leading to the conclusion that one or both of the putative parents have not yet been discovered or are extinct. A range of observations concerning allopolyploid speciation were categorized as follows: (1) verification of previous hypotheses regarding parentage (e.g., I. riparia, I. appalachiana), (2) determination that two morphologically distinct allotetraploid species can share the same parentage (I. azorica and I. acadiensis), (3) recognition of a cryptic allotetraploid species, indicated by the presence of different parental genomes (I. "appalachiana" from Florida), and (4) identification of allotetraploid species with one or two unknown parents (e.g., I. tuckermanii, I. acadiensis, I. azorica, and I. hyemalis). Some sequences from diploid species are remarkably uniform among populations (e.g., I. echinospora from various locations in North America, Iceland, and Wales), while others are variable at the subspecies level (e.g., northern and southern populations within I. engelmannii).10aAllopolyploidy10aHybrid origins10aIsoetes10aLEAFY intron1 aHoot, S.B.1 aNapier, N.S.1 aTaylor, W.C.  uhttp://www.scopus.com/inward/record.url?eid=2-s2.0-11444256350&partnerID=40&md5=420a4ad06820ce82f60d7a70e7db9dec02184nam a2200205   4500008004100000245010800041210007100149260001200220300001400232490000700246520150100253653001701754653001501771653001201786653001401798100001501812700001701827700001701844856011701861       2006                        eng d00aPhylogeny and biogeography of Isoëtes (Isoëtaceae) based on nuclear and chloroplast DNA sequence data0 aPhylogeny and biogeography of Isoëtes Isoëtaceae based on nuclea  c2006///  a449 - 4600 v313 aDespite its ancient origins, worldwide distribution, and adaptation to diverse habitats, Isoëtes species have a highly conserved morphology, making it difficult to resolve phylogenetic relationships using morphological characters. In this paper, we report the results from various analyses (maximum parsimony, maximum likelihood, and Bayesian inference) for Isoëtes species from around the world based on nucleotide sequences from the nuclear internal transcribed spacer (ITS) and chloroplast atpB/rbcL intergenic spacer regions. The trees resulting from our analyses of the combined data contain six major well-supported clades (bootstrap ≥ 90%, posterior probabilities = 1.00): A clade with possible Gondwanan affinities (I. australis, I. coromandelina, I. panamensis, I. cubana, I. jamaicensis); a South African clade (I. capensis, I. toximontana, I. stellenbossiensis, I. stephansenii); a largely Northern Hemisphere clade (I. nuttallii, I. orcuttii, I. minima, I. dixitei, I. abyssinica, I. olympica, I. longissima, I. velata); an Asian/Australasian clade (I. drummondii, I. gunnii, I. pusilla, I. kirkii, I. muelleri, I. taiwanensis, I. japonica, I. yunguiensis, I. habbemensis); a Mediterranean clade (I. histrix and I. setacea); and a poorly resolved clade consisting of 12 new world species (American species complex). Our results are compared to past classifications and various biogeographical scenarios are explored. © Copyright 2006 by the American Society of Plant Taxonomists.10aBiogeography10aIsoetaceae10aIsoetes10aPhylogeny1 aHoot, S.B.1 aTaylor, W.C.1 aNapier, N.S.  uhttp://www.scopus.com/inward/record.url?eid=2-s2.0-67650146436&partnerID=40&md5=c418d4b55db9dd7f2436a8d3189f155201966nas a2200217   4500008004100000245010000041210007000141260001200211300001400223490000700237520123800244653001501482653001201497653001401509653002101523653002201544653003001566100002001596700001501616856011701631       2006                        eng d00aInferring the root of Isoëtes: Exploring alternatives in the absence of an acceptable outgroup0 aInferring the root of Isoëtes Exploring alternatives in the abse  c2006///  a258 - 2700 v313 aThe ancient divergence between the lycopsid genus Isoëtes and its closest living relative (Selaginella) has resulted in considerable morphological and genetic disparity, yet within Isoëtes there is remarkable morphological and genetic uniformity. This has made it difficult to identify the phylogenetic root of the genus. In this study, we addressed this problem and characterized the early branching patterns within Isoëtes using an expanded set of taxa and three molecular markers. We assessed the saturation in the molecular data sets, tested for differences in evolutionary rate, determined the stability of the ingroup topology, and evaluated the applicability of the molecular clock. We then explored three alternative rooting approaches: outgroup, midpoint, and maximum likelihood under the assumption of a molecular clock. Attempts to infer the root of Isoëtes using the outgroup approach were severely hindered by the effects of saturation, but the results from midpoint rooting and the enforcement of the molecular clock were highly consistent among the data sets. We identify the root of Isoëtes to be located among three major, highly supported clades. © Copyright 2006 by the American Society of Plant Taxonomists.10aIsoetaceae10aIsoetes10aLycophyte10aMidpoint rooting10aPhylogenetic root10aRelative rate comparisons1 aSchuettpelz, E.1 aHoot, S.B.  uhttp://www.scopus.com/inward/record.url?eid=2-s2.0-33745493624&partnerID=40&md5=8d3abb9eb77572545e97747f1aaf51a5