@article {67,
	title = {Genome Scanning for Interspecific Differentiation Between Two Closely Related Oak Species [Quercus robur L. and Q. petraea (Matt.) Liebl.]},
	journal = {Genetics},
	volume = {168},
	year = {2004},
	month = {2004},
	pages = {1615-1626},
	abstract = {Interspecific differentiation values (GST) between two closely related oak species (Quercus petraea and Q. robur) were compiled across different studies with the aim to explore the distribution of differentiation at the genome level. The study was based on a total set of 389 markers (isozymes, AFLPs, SCARs, microsatellites, and SNPs) for which allelic frequencies were estimated in pairs of populations sampled throughout the sympatric distribution of the two species. The overall distribution of GST values followed an L-shaped curve with most markers exhibiting low species differentiation (GST < 0.01) and only a few loci reaching >10\% levels. Twelve percent of the loci exhibited significant GST deviations to neutral expectations, suggesting that selection contributed to species divergence. Coding regions expressed higher differentiation than noncoding regions. Among the 389 markers, 158 could be mapped on the 12 linkage groups of the existing Q. robur genetic map. Outlier loci with large GST values were distributed over 9 linkage groups. One cluster of three outlier loci was found within 0.51 cM; but significant autocorrelation of GST was observed at distances <2 cM. The size and distribution of genomic regions involved in species divergence are discussed in reference to hitchhiking effects and disruptive selection.},
	url = {http://www.genetics.org/cgi/content/abstract/168/3/1615},
	author = {Scotti-Saintagne, C. and Mariette, S. and Porth, I. and Goicoechea, P.G. and Barreneche, T. and Bodenes, C. and Burg, K. and Kremer, A.}
}
@article {109,
	title = {Morphological and RAPD analysis of hybridization between Quercus affinis and Q. laurina (fagaceae), two Mexican red oaks},
	journal = {American Journal of Botany},
	volume = {91},
	year = {2004},
	month = {2004},
	pages = {401-409},
	abstract = {Quercus affinis and Q. laurina are two closely related Mexican red oaks with partially overlapping distributions. Within the area of overlap, there are localities where morphological intergradation occurs. A previous hypothesis explained this pattern as a result of secondary contact between the two species, followed by hybridization and introgression. This possibility was analyzed here by examining foliar and genetic variation in 16 localities situated along a macrogeographic gradient, which included morphologically representative populations of both species and populations from within the area of overlap. Maximum-likelihood hybrid index scores calculated from nine semi-diagnostic RAPD markers indicated a shift in the genetic composition of populations from one species to the other along the macrogeographic gradient, with genetically intermediate populations situated in the area of overlap. Foliar variation followed a partially congruent pattern, but Q. laurina-like morphology predominated in some of the genetically intermediate populations. There were several instances of correlated frequency changeovers of single RAPD markers and morphological characters along the macrogeographic gradient and a few cases of markedly parallel patterns between markers. The results were interpreted as consistent with a hypothesis of secondary contact between the two oak species that has resulted in some differential introgression among markers.},
	url = {http://www.amjbot.org/cgi/content/abstract/91/3/401},
	author = {Gonz and Arias, D.M. and Valencia, S. and Oyama, K.}
}
@article {115,
	title = {Selection and disperal in a multispecies oak hybrid zone},
	journal = {Evolution},
	volume = {58},
	year = {2004},
	month = {2004},
	pages = {261-269},
	abstract = {The four western North American red oak species (Quercus wislizeni, Q. parvula, Q. agrifolia, and Q. kelloggii) are known to produce hybrid products in all interspecific combinations. However, it is unknown whether hybrids are transitory resulting from interspecific gene flow or whether they are maintained through extrinsic selection. Here, we examine cryptic hybrid structure in Q. wislizeni through a broad region including contact and isolation from three other western North American red oaks using amplified fragment length polymorphism molecular markers. All four species were simultaneously detected in the genetic background of individuals morphologically assigned to Q. wislizeni, although the contribution of Q. kelloggii was minor. In some cases, introgression was detected well outside the region of sympatry with one of the parental species. Molecular structure at the individual level indicated this was due to long-distance pollen dispersal and not to local extinction of parental species. Species admixture proportions were correlated with climatic variables and greater proportions of Q. agrifolia and Q. parvula were present in the genetic background of Q. wislizeni in sites with cooler and more humid summers, corresponding with habitat preferences of the parental species. Partial Mantel tests indicated that climate was more important than distance from pollen source in this association. Despite high levels of introgression, species integrity was maintained in some populations in close proximity to the other species, providing further support to environmental selection in determining population genetic structure. Thus, the contribution of species mixtures to population genetic structure varies across the landscape according to availability of pollen, but more importantly to varying environmental selection pressures that produce a complex pattern of hybrid and pure gene pools.},
	keywords = {Climate, HYBRIDIZATION, introgression, pollen dispersal, Quercus wislizeni, red oaks},
	author = {Dodd, R.S. and Afzal-Rafii, Z.}
}
@article {110,
	title = {Two-generation analysis of pollen flow across a landscape V: A stepwise approach for extracting factors contributing to pollen structure},
	journal = {Heredity},
	volume = {92},
	year = {2004},
	note = {200400144680ArticleEnglish},
	month = {2004},
	pages = {204-211},
	abstract = {Patterns of pollen dispersal are central to both the ecology and evolution of plant populations. However, the mechanisms controlling either the dispersal process itself or our estimation of that process may be influenced by site -specific factors such as local forest structure and nonuniform adult genetic structure. Here, we present an extension of the AMOVA model applied to the recently developed TWOGENER analysis of pollen pool structure. This model, dubbed the Stepwise AMOVA (StAMOVA), focuses on determining to what extent ecological, demographic, and/or environmental factors influence the observed genetic variation in spatially separated pollen pools. The analysis is verified for efficacy, using an extensive battery of simulations, illustrating: (1) how nonuniform adult genetic structure influences the differentiation of spatially separated pollen pools, and (2) how effectively the Stepwise analysis performs in carrying out the appropriate corrections. Finally, the model is applied to a Quercus alba data set, from which we have prior evidence that the adult genetic structure is nonuniformly distributed across the sampling landscape. From this data set, we show how the Stepwise model can be applied to remove the effects of spatial adult genetic structure on pollen pool differentiation and contrast these results with those derived from the original TWOGENER analysis.},
	keywords = {[26070-] Fagaceae-, AMOVA-model: mathematical-and-computer-techniques, Angiospermae-, Dicots-, Dicotyledones-, Fagaceae-: Angiosperms-, gene-flow, Genetics-, Mathematical-Biology: Computational-Biology, Plantae-, Plants-, pollen-: reproductive-system, Quercus-alba (Fagaceae-): species-, Reproduction-, Spermatophyta-, Spermatophytes-, Vascular-Plants},
	author = {Dyer, R.-J. and Westfall, R.-D. and Sork, V.-L. and Smouse, P.-E.}
}
