Journal ArticleDOI
The genic view of the process of speciation
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Significantly, the genetic architecture underlying RI, the patterns of species hybridization and the molecular signature of speciation genes all appear to support the view that RI is one of the manifestations of differential adaptation, as Darwin (1859) suggested.Abstract:
The unit of adaptation is usually thought to be a gene or set of interacting genes, rather than the whole genome, and this may be true of species differentiation. Defining species on the basis of reproductive isolation (RI), on the other hand, is a concept best applied to the entire genome. The biological species concept (BSC; Mayr, 1963) stresses the isolation aspect of speciation on the basis of two fundamental genetic assumptions ‐ the number of loci underlying species differentiation is large and the whole genome behaves as a cohesive, or coadapted genetic unit. Under these tenets, the exchange of any part of the genomes between diverging groups is thought to destroy their integrity. Hence, the maintenance of each species’ genome cohesiveness by isolating mechanisms has become the central concept of species. In contrast, the Darwinian view of speciation is about differential adaptation to different natural or sexual environments. RI is viewed as an important by product of differential adaptation and complete RI across the whole genome need not be considered as the most central criterion of speciation. The emphasis on natural and sexual selection thus makes the Darwinian view compatible with the modern genic concept of evolution. Genetic and molecular analyses of speciation in the last decade have yielded surprisingly strong support for the neo-Darwinian view of extensive genetic differentiation and epistasis during speciation. However, the extent falls short of what BSC requires in order to achieve whole-genome ‘cohesiveness’. Empirical observations suggest that the gene is the unit of species differentiation. Significantly, the genetic architecture underlying RI, the patterns of species hybridization and the molecular signature of speciation genes all appear to support the view that RI is one of the manifestations of differential adaptation, as Darwin (1859, Chap. 8) suggested. The nature of this adaptation may be as much the result of sexual selection as natural selection. In the light of studies since its early days, BSC may now need a major revision by shifting the emphasis from isolation at the level of whole genome to differential adaptation at the genic level. With this revision, BSC would in fact be close to Darwin’s original concept of speciation.read more
Citations
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Landscape genetics: combining landscape ecology and population genetics
TL;DR: A new approach has emerged for analyzing spatial genetic data without requiring that discrete populations be identified in advance, and promises to facilitate the understanding of how geographical and environmental features structure genetic variation at both the population and individual levels.
Journal ArticleDOI
Hybridization and speciation
Richard J. Abbott,Dirk C. Albach,Stephen W. Ansell,Jan W. Arntzen,Stuart J. E. Baird,Nicolas Bierne,Janette W. Boughman,Alan Brelsford,C. A. Buerkle,Richard J. A. Buggs,Roger K. Butlin,Ulf Dieckmann,Fabrice Eroukhmanoff,Andrea Grill,Sara Helms Cahan,Jo S. Hermansen,Godfrey M. Hewitt,Alan G. Hudson,Chris D. Jiggins,Julia C. Jones,Barbara Keller,T. Marczewski,James Mallet,Paloma Martínez-Rodríguez,Markus Möst,Sean P. Mullen,Richard A. Nichols,Arne W. Nolte,Christian Parisod,Karin S. Pfennig,Amber M. Rice,Michael G. Ritchie,Burkhardt Seifert,Carole M. Smadja,Rike B. Stelkens,Jacek M. Szymura,Risto Väinölä,Jochen B. W. Wolf,Dietmar Zinner +38 more
TL;DR: A perspective on the context and evolutionary significance of hybridization during speciation is offered, highlighting issues of current interest and debate and suggesting that the Dobzhansky–Muller model of hybrid incompatibilities requires a broader interpretation.
Journal ArticleDOI
The power and promise of population genomics: from genotyping to genome typing
TL;DR: The most useful contribution of the genomics model to population genetics will be improving inferences about population demography and evolutionary history.
Journal ArticleDOI
The rapid evolution of reproductive proteins.
TL;DR: Sequence comparisons and functional studies are beginning to show the extent to which the rapid divergence of reproductive proteins is involved in the speciation process.
Journal ArticleDOI
Divergent selection and heterogeneous genomic divergence.
TL;DR: It is concluded that divergent selection makes diverse contributions to heterogeneous genomic divergence, and the number, size, and distribution of genomic regions affected by selection varied substantially among studies, leading us to discuss the potential role of Divergent selection in the growth of regions of differentiation (i.e. genomic islands of divergence), a topic in need of future investigation.
References
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Book
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TL;DR: In this paper, secondary sexual characters of fishes, amphibians and reptiles are presented. But the authors focus on the secondary sexual characteristics of fishes and amphibians rather than the primary sexual characters.
Journal ArticleDOI
An Introduction to Population Genetics Theory
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