一個新的數(shù)目模型顯示，當宿主和其寄生蟲各自都有許多管理彼此間相互作用的特質(zhì)時,，宿主獨特的進化優(yōu)勢可幫助它生存下來,。相關論文發(fā)表在Nature雜志上。
這個重要的研究成果也許解釋人類以及動植物是如何進化以抵抗寄生蟲的強攻的,。
進化理論認為,，寄生蟲和病原體要比它們的宿主進化的速度快，因為它們的代長短,，且要經(jīng)歷嚴酷的篩選,。但這就形成了一個悖論：宿主，或者說“寄生犧牲者”是如何不顧進化更快的寄生敵人的持續(xù)攻擊而生存,，甚至還發(fā)展繁榮呢,？
“為了研究這些特質(zhì)的數(shù)量對共進化的影響，我們使用定量遺傳學及基于個體的模擬來分析犧牲者-掠奪者系統(tǒng)的模型,，”研究論文的作者Gilman說,。“我們可以發(fā)現(xiàn)，當多個特質(zhì)（而非單一某個特質(zhì)）管理宿主與寄生蟲之間的反應時,，犧牲者在進化的軍備競賽中占得上風。”
在自然界,，物種之間的相互作用通常受到多個特質(zhì)的影響,。例如，歐洲防風草對結網(wǎng)蟲的抵抗取決于其開花的時期以及所有含有的具有殺蟲特性的特定化學成分的濃度,。相似地,，硬骨魚，例如金槍魚和大比目魚擁有多個防御性特質(zhì),，比如粘膜屏障,、殺滅性分泌物等,，寄生蟲必須克服這些防御才能成功寄生到宿主上。
研究表明,，具有多個攻擊與防御機制也許可以幫助被寄生一方進化并維持與寄生者之間的低互作率,。此外，該研究認為,，多特質(zhì)的共進化也許可幫助植物限制食草動物所造成的損傷,，這也許還可以解釋為什么世界是綠色的。（生物谷Bioon.com）
doi:10.1038/nature10853
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Coevolution in multidimensional trait space favours escape from parasites and pathogens
R. Tucker Gilman, Scott L. Nuismer & Dwueng-Chwuan Jhwueng
Almost all species are subject to continuous attack by parasites and pathogens. Because parasites and pathogens tend to have shorter generation times and often experience stronger selection due to interaction than their victims do, it is frequently argued that they should evolve more rapidly and thus maintain an advantage in the evolutionary race between defence and counter-defence. This prediction generates an apparent paradox: how do victim species survive and even thrive in the face of a continuous onslaught of more rapidly evolving enemies5? One potential explanation is that defence is physiologically, mechanically or behaviourally easier than attack, so that evolution is less constrained for victims than for parasites or pathogens. Another possible explanation is that parasites and pathogens have enemies themselves and that victim species persist because parasites and pathogens are regulated from the top down and thus generally have only modest demographic impacts on victim populations. Here we explore a third possibility: that victim species are not as evolutionarily impotent as conventional wisdom holds, but instead have unique evolutionary advantages that help to level the playing field. We use quantitative genetic analysis and individual-based simulations to show that victims can achieve such an advantage when coevolution involves multiple traits in both the host and the parasite.
