01412nas a2200181   4500008004100000245006400041210006300105300001400168490000700182520089500189653001501084653001401099653001201113653001101125653002701136100002701163856004001190       1980                        eng d00aSexual Isolation, Speciation and the Direction of Evolution0 aSexual Isolation Speciation and the Direction of Evolution  a437–4440 v343 aVarious concepts of evolutionary biology are reviewed to emphasize the significance of premating isolation barriers in processes of speciation. Concepts such as sexual selection, genetic drift, and the Founder Principle appear to lend support to Muller's views that premating isolating mechanisms arise as by-products of natural selection in allopatry. Examples are presented in support of this view and in contrast to that held by Fisher and Dobzhansky, who envisioned such mechanisms as arising upon recontact of populations in which some postmating isolating mechanism had arisen. Additionally, a hypothesis proposed by Kaneshiro (1976) which enables interpretation of the one-sided mating preference (asymmetrical isolation) observed between populations of Drosophila is discussed. Such a hypothesis, if valid, permits inferences of direction of evolution among closely related species.10adrosophila10aevolution10ainsects10amating10areproductive-isolation1 aKaneshiro, Kenneth, Y.  uhttp://www.jstor.org/stable/240821302596nas a2200229   4500008004100000245011400041210006900155260026000224300001600484490000700500520164700507653001802154653001302172653001102185653001502196653002102211100002202232700002302254700001502277700001902292856005502311       2008                        eng d00aEXPERIMENTAL EVIDENCE THAT SEXUAL CONFLICT INFLUENCES THE OPPORTUNITY, FORM AND INTENSITY OF SEXUAL SELECTION0 aEXPERIMENTAL EVIDENCE THAT SEXUAL CONFLICT INFLUENCES THE OPPORT  aEvolution & Ecology Research Centre and School of Biological, Earth & Environmental Sciences, University of New South Wales, Sydney, New South Wales 2052, Australia; E-mail: m.hall@student.unsw.edu.au; Zoologisches Museum der Universitt Zrich, Winterthure  a2305–23150 v623 aSexual interactions are often rife with conflict. Conflict between members of the same sex over opportunities to mate has long been understood to effect evolution via sexual selection. Although conflict between males and females is now understood to be widespread, such conflict is seldom considered in the same light as a general agent of sexual selection. Any interaction between males or females that generates variation in fitness, whether due to conflict, competition or mate choice, can potentially influence sexual selection acting on a range of male traits. Here we seek to address a lack of direct experimental evidence for how sexual conflict influences sexual selection more broadly. We manipulate a major source of sexual conflict in the black field cricket, Teleogryllus commodus, and quantify the resulting changes in the nature of sexual selection using formal selection analysis to statistically compare multivariate fitness surfaces. In T. commodus, sexual conflict occurs over the attachment time of an external spermatophore. By experimentally manipulating the ability of males and females to influence spermatophore attachment, we found that sexual conflict significantly influences the opportunity, form, and intensity of sexual selection on male courtship call and body size. When males were able to harass females, the opportunity for selection was smaller, the form of selection changed, and sexual selection was weaker. We discuss the broader evolutionary implications of these findings, including the contributions of sexual conflict to fluctuating sexual selection and the maintenance of additive genetic variation.10acommunication10acrickets10amating10aorthoptera10asexual-selection1 aHall, Matthew, D.1 aBussière, Luc, F.1 aHunt, John1 aBrooks, Robert  uhttp://dx.doi.org/10.1111/j.1558-5646.2008.00436.x