Maintenacne of Parent-Species Reservoirs in a Complex Hybrid Zone

复杂混合带亲种储层的维护

• 批准号: 9708074
• 负责人: Thomas Hilbish
• 金额: $ 11万
• 依托单位: University of South Carolina at Columbia
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-01-15 至 2000-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9708074&HistoricalAwards=false
• 关键词: Maintenacne; Parent; Species; Reservoirs; Complex

Hilbish 9708074 The PIs have been conducting a detailed analysis of a hybrid zone between two species of marine mussels, Mytilus edulis and M. galloprovincialis that are sympatric in Europe. The PIs' have shown that 1) strong directional selection occurs within hybrid populations that eliminates Mytilus edulis and M. edulis-like hybrids, 2) directional selection is offset by immigration from pure populations of M. edulis, 3) the balance between dispersal and selection is presently stable, and 4) hybridization has been an important feature in the evolutionary history of these species. These studies focus future research in a new direction: the primary issue in understanding the dynamics of this hybrid zone is to determine how pure populations of M. edulis are maintained. The maintenance of pure populations of Mytilus edulis is an essential element of the dynamic equilibrium between dispersal and directional selection that maintains and shapes this hybrid zone. The PI will propose to test the hypothesis that M. edulis has a superior physiological capacity to cope with silt in its diet and that pure populations of this species are selectively maintained in estuarine environments where silt concentrations are high. This hypothesis was suggested by the observation that pure populations of M. edulis are associated with estuaries that have high silt loads and preliminary results from separate studies that indicate that M. edulis may have a much greater absorption efficiencies when exposed to diet containing high concentrations of silt. The PI will also propose a combination of laboratory and field experiments to test this hypothesis. Laboratory experiments will test for the proposed physiological differences between M. edulis and M. galloprovincialis while the field experiments are necessary to demonstrate that these differ ences have significant consequences in nature.

Hilbish 9708074 PI 一直在对欧洲同域分布的两种海洋贻贝（贻贝和贻贝）之间的杂交区进行详细分析。 PI表明：1）在杂交群体中发生了强烈的定向选择，消除了贻贝和类似贻贝的杂种；2）定向选择被纯贻贝种群的移民所抵消；3）扩散和选择之间的平衡目前是稳定的；4）杂交一直是这些物种进化史上的一个重要特征。这些研究将未来的研究集中在一个新的方向：了解这个混合区动态的首要问题是确定如何维持纯种的美味贻贝种群。贻贝纯种群的维持是分散和定向选择之间动态平衡的重要组成部分，从而维持和塑造了这个混合区。 PI 将提议检验以下假设：美味贻贝具有卓越的生理能力来应对其饮食中的淤泥，并且该物种的纯种群选择性地维持在淤泥浓度较高的河口环境中。 这一假设是通过观察发现的，即美味贻贝的纯种群与具有高淤泥负荷的河口有关，并且单独研究的初步结果表明，当暴露于含有高浓度淤泥的饮食时，美味贻贝可能具有更高的吸收效率。 PI 还将提议结合实验室和现场实验来检验这一假设。实验室实验将测试 M. edulis 和 M. galloprovincialis 之间所提出的生理差异，而现场实验则有必要证明这些差异在自然界中具有重大影响。