Reinforcement in a Zone of Overlap and Hybridization

重叠和杂交区域的强化

• 批准号: 9006484
• 负责人: Daniel Howard
• 金额: $ 22.5万
• 依托单位: New Mexico State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1990
• 资助国家: 美国
• 起止时间: 1990-08-01 至 1994-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9006484&HistoricalAwards=false
• 关键词: Reinforcement; Zone; Overlap; Hybridization

The research proposed by Daniel Howard and John Doherty addresses some of the most difficult problems in biology; namely, how does reproductive isolation (the absence of interbreeding between individuals of different species) develop as one species splits into two and, in particular, what is the role of selection against hybridization in the evolution of reproductive barriers? Answers to these questions are central to an understanding to the development and conservation of biological diversity on earth. The questions will be approached by studying ground crickets that are in the process of splitting to form new species. Answers obtained from the study will be relevant to all sexually reproducing organisms. Research over the past three years has identified male calling song differences as a potential reproductive barrier between the newly forming species, Allonemobius fasciatus and A. socius. The identification of this potential barrier during a critical stage of species formation provides a rare opportunity to study the evolution of reproductive isolation during a speciation event. During the next three years, the hypothesis of reinforcement will be tested. This hypothesis states that the calling song displacement exhibited by A. fasciatus in areas where it occurs with A. socius represents a reproductive barrier that has evolved as a consequence of selection against hybridization. The work will include investigations of : (1) geographic variation in male calling song, (2) female response to song, (3) the genetics of song differences, (4) the cost of a hybrid mating, and (5) sperm competition. The proposed studies will not only provide a rigorous test of the hypothesis of reinforcement, but they will provide fundamental information on a trait potentially responsible for reproductive isolation. Only by combining studies of the genetics, behavioral ecology, and developmental biology of specific traits serving as reproductive barriers with analyses of geographic distribution patterns, will biologists arrive at an understanding of the process of speciation. The proposed research should lead into even more rigorous studies of the acquisition of reproductive isolation between A. fasciatus and socius. These species are rapidly becoming a model system for the study of biological processes. From an applied perspective, the family Gryllidae (crickets) includes some very serious agricultural pests. The proposed research will provide badly needed information on the reproductive biology of crickets - information that can be used to help develop biological control programs.

丹尼尔·霍华德（Daniel Howard）和约翰·多尔蒂（John Doherty）提出的研究解决了生物学中一些最困难的问题；也就是说，当一个物种分裂成两个物种时，生殖隔离（不同物种个体之间没有杂交）是如何发展的，特别是，在生殖障碍的进化中，选择对杂交的作用是什么？这些问题的答案对于理解地球生物多样性的发展和保护至关重要。这些问题将通过研究正在分裂形成新物种的地蟋蟀来解决。从这项研究中得到的答案将与所有有性繁殖的生物体相关。过去三年的研究已经确定，雄性鸣叫的差异是新形成的物种——fasciatus Allonemobius和a . socius之间潜在的生殖障碍。在物种形成的关键阶段发现这种潜在屏障，为研究物种形成过程中生殖隔离的进化提供了难得的机会。在接下来的三年里，强化假说将得到检验。这一假说认为，筋膜拟南猿在与社会拟南猿发生鸣叫的地区所表现出的鸣叫移位，代表了一种生殖障碍，这是选择反对杂交的结果。这项工作将包括调查：(1)雄性鸣声的地理差异，(2)雌性对鸣声的反应，(3)鸣声差异的遗传学，(4)杂交交配的成本，以及(5)精子竞争。拟议的研究不仅将为强化假说提供严格的检验，而且还将提供有关可能导致生殖隔离的特征的基本信息。只有将遗传学、行为生态学和发育生物学的研究与地理分布模式的分析结合起来，生物学家才能理解物种形成的过程。这项研究应该会导致更严格的研究筋膜库蚊和社会性库蚊之间生殖隔离的获得。这些物种正迅速成为研究生物过程的模型系统。从应用的角度来看，蟋蟀科包括一些非常严重的农业害虫。拟议中的研究将提供关于蟋蟀生殖生物学的急需信息，这些信息可用于帮助制定生物控制计划。