LIFE-HISTORY TRADE-OFFS AND THE EVOLUTION OF PATHOGEN RESISTANCE - COMPETITION BETWEEN HOST STRAINS
LIFE-HISTORY TRADE-OFFS AND THE EVOLUTION OF PATHOGEN RESISTANCE - COMPETITION BETWEEN HOST STRAINS
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DOI：
10.1098/rspb.1994.0122
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发表时间：
1994-09-22
影响因子：
4.7
通讯作者：
BEGON, M
中科院分区：
文献类型：
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作者：
BOWERS, RG;BOOTS, M;BEGON, M
一个“抗性”和一个“敏感”菌株的自我调节的宿主物种的动态，在直接传播的病原体的存在下，进行了研究。这两种菌株权衡病原体传播性（作为病原体抗性的一个方面）的差异对出生率和/或耐拥挤的差异。取决于参数值，可以消除任一菌株，或者两者可以共存（沿着病原体）。共存（多态性），毫不奇怪，需要两种菌株所拥有的不同优势之间的适当平衡。然而，通过这种平衡共存的可能性随着菌株之间差异的程度而非线性变化：两种非常相似的菌株之间共存的可能性最小。抗性最有可能在具有许多害虫特征的宿主中进化。此外，对于高致病性病原体，“敏感”菌株可能排除“抗性”菌株，因为其较高的生长速率比降低的传播性更有效地对抗病原体。“抗性”可以存在于与病原体直接相关的参数之外的参数中。虽然没有周期出现，也没有发现混沌行为，但通常可以观察到平衡的振荡方法，这表明在（更多变的）真实的世界中可能存在可观察到的应变频率振荡。
The dynamics of a 'resistant' and a 'susceptible' strain of a self-regulated host species, in the presence of a directly transmitted pathogen, is investigated. The two strains trade off differences in pathogen transmissibility (as an aspect of pathogen resistance) against differences in birth rate and/or resistance to crowding. Depending on parameter values, either strain may be eliminated, or the two may coexist (along with the pathogen). Coexistence (polymorphism), unsurprisingly, requires an appropriate balance between the different advantages possessed by the two strains. The probability of coexistence through such a balance, however, varies nonlinearly with the degree of difference between the strains: coexistence is least likely between two very similar strains. Resistance is most likely to evolve in hosts with the characteristics of many insect pests. Moreover, with highly pathogenic pathogens, a 'susceptible' strain may exclude a 'resistant' strain because its higher growth rate is more effective against the pathogen than reduced transmissibility. 'Resistance' can reside in parameters other than those directly associated with the pathogen. Although no cycles arise and no chaotic behaviour is found, an oscillatory approach to equilibrium is commonly observed, signalling the possibility of observable oscillations in strain frequency in the (more variable) real world.