| 项目编号: | BB/J014109/1
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| 项目名称: | Species interactions and the evolution of biological diversity: visual signalling in antagonistic and mutalistic coevolution |
| 作者: | Claire N. Spottiswoode
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| 承担单位: | University of Cambridge
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| 批准年: | 2012
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| 开始日期: | 2013-21-02
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| 结束日期: | 2020-31-12
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| 资助金额: | GBP911470
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| 资助来源: | UK-BBSRC
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| 项目类别: | Fellowship
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| 国家: | UK
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| 语种: | 英语
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| 特色学科分类: | Animal Science
; Ecol, biodivers. & systematics
; Genetics & development
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| 英文摘要: | Much of the world's biological diversity was born of and crucially depends upon interactions between different species. They give us some of the most astonishing examples of adaptation seen in nature: a cuckoo egg perfectly mimicking that of its host, or a long-tongued fly pollinating a long-spurred orchid. These are products of coevolution, which is the process by which two or more species reciprocally influence one another's evolution. But coevolution is not only a potent force in generating biodiversity: it is crucial to human challenges such as conservation of ecosystems and the services they provide us, biocontrol, and the ever-changing threat of infectious disease and drug resistance. To address these challenges, we need a thorough understanding of the evolutionary mechanisms involved.
This project aims better to understand coevolution and the processes generating biological diversity by studying the interactions between birds and the antagonists they battle against (their brood parasites), and the mutualists they cooperate with (the plants they pollinate). Interactions between species are at their most ancient in the tropics, where they might be most revealing of general evolutionary processes. My parasitic research will therefore exploit three independently evolved tropical brood parasitic systems studied in Zambia. Brood parasites such as cuckoos are the cheats of the bird world, that exploit the care of other species to raise their young. They can become locked in coevolutionary arms races with their hosts, as parasites evolve ever better manipulation of hosts (such as mimicry of host eggs), and hosts respond with ever more refined defences (such as rejecting mimetic eggs).
In this project, I will first ask how interactions between species can generate diversity among individuals, and how this is shaped by visual perception. The Cuckoo Finch and African Cuckoo in Zambia are involved in biological arms races in bird egg appearance, whereby different host females are continually evolving new egg types to escape mimicry by their pursuing parasite. I will ask how hosts might make their eggs most difficult to mimic (just as the watermarks of banknotes deter forgers), how different hosts might affect one another's diversification, and how evolution proceeds when parasites achieve almost perfect egg forgeries. To do so I will carry out field experiments at hosts nests, together with computer modelling of vision in order to express egg appearance through a bird's eye, since birds vision is superior to our own. I will then ask whether similar processes might operate in mutualistic interactions: I will test whether visual discrimination by bird pollinators favours flower colour divergence or convergence between species flowering near one another, and thus cause plants of the same species to diversify between different local communities.
Second, I will attempt to solve a centuries-old conundrum for host-parasite research: how do different female brood parasites of the same species lay eggs that mimic those of their chosen host, despite interbreeding with males raised by other hosts? An hypothesis is that these specialised adaptations are inherited in the female line alone, via the female-specific avian W chromosome. In Zambia we have discovered that lineages of parasitic females have stayed perfectly faithful to their chosen hosts for millions of years, which could allow such specialisation to evolve. I propose to test this by locating the genes involved in mimicry of different host species and different host signatures. I will do so by way of breeding experiments on captive Cuckoo Finches, in combination with advanced DNA sequencing and studies of gene expression in the oviduct where eggs are formed. Finally, I will locate the host genes involved in generating complex egg signatures, to reveal whether similar genetic mechanisms have convergently evolved both in hosts and their parasites that so beautifully mimic them. |
| 资源类型: | 项目
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| 标识符: | http://119.78.100.158/handle/2HF3EXSE/102257
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| Appears in Collections: | 科学计划与规划
气候变化与战略
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作者单位: | University of Cambridge
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| Recommended Citation: | |
Claire N. Spottiswoode. Species interactions and the evolution of biological diversity: visual signalling in antagonistic and mutalistic coevolution. 2012-01-01.
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