One Host Shift Leads to Another: Formation of Host Races in a Gall- and Stem-Boring Beetle

一种宿主转变导致另一种宿主转变：钻瘿和茎甲虫中宿主种族的形成

• 批准号: 9806339
• 负责人: Warren Abrahamson
• 金额: $ 25万
• 依托单位: Bucknell University
• 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: 1998-10-01 至 2002-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9806339&HistoricalAwards=false
• 关键词: Host; Shift; Leads; Another; Formation

DEB-9806339 Warren G. Abrahamson & Micky Eubanks New species are known to arise when geographic barriers divide an existing species into two or more isolated populations. When mountains, oceans, or other barriers prevent reproduction between the isolated populations, each can evolve along an independent path. If geographic isolation lasts long enough, the populations may diverge so much that interbreeding is no longer possible -- one species divides into several. With parasites such as herbivorous insects, barriers to genetic exchange may arise not out of geography, but out of behavior. When mating occurs only on the host plant, a subpopulation consistently choosing one host will not mate with that choosing the other. Thus, speciation can occur in the absence of geographic separation when the two subpopulations are sympatric. Many have argued that the conditions for sympatric speciation are too restrictive for it to be important. Our extensive work on flies that induce galls on goldenrod plants and our preliminary work with a stem and gall-boring beetle indicate that host choice can be a barrier to genetic exchange. We will study a host shift and potential host-race formation by a common tumbling flower beetle associated with two species of goldenrod in the eastern United States. Our study system is unique in that a host shift and subsequent host-race formation by one herbivorous insect may have directly contributed to the host shift and host-race formation of a second, unrelated species. Given that nearly half of animal species are parasites, sympatric speciation may be an important source of the earth's biodiversity.

Warren G.亚伯拉罕森·米奇·尤班克斯 当地理屏障将一个现有物种分成两个或两个以上孤立的种群时，新物种就会出现。当山脉、海洋或其他障碍物阻止隔离种群之间的繁殖时，每个种群都可以沿着一条独立的道路进化。如果地理隔离持续足够长的时间，种群可能会分化得如此之大，以至于杂交不再可能--一个物种分裂成几个物种。 对于像食草昆虫这样的寄生虫，基因交换的障碍可能不是来自地理，而是来自行为。当交配只发生在寄主植物上时，一个持续选择一种寄主的亚群将不会与选择另一种寄主的亚群交配。因此，当两个亚群同域分布时，物种形成可以在没有地理分离的情况下发生。 许多人认为，同域物种形成的条件限制太多，因此它并不重要。我们对在一枝黄花植物上诱导虫瘿的苍蝇的广泛研究，以及对茎和虫瘿甲虫的初步研究表明，宿主选择可能是遗传交换的障碍。我们将研究一个主机转移和潜在的主机种族的形成，由一个共同的翻滚花甲虫与两个物种的一枝黄花在美国东部。我们的研究系统是独特的，一个草食性昆虫的主机转移和随后的主机种族的形成可能直接促成了主机转移和主机种族的形成的第二个，不相关的物种。鉴于近一半的动物物种是寄生虫，同域物种形成可能是地球生物多样性的重要来源。