Experimental evolution with E. coli in diverse resource environments. I. Fluctuating environments promote divergence of replicate populations.
Experimental evolution with E. coli in diverse resource environments. I. Fluctuating environments promote divergence of replicate populations.
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DOI：
10.1186/1471-2148-10-11
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发表时间：
2010-01-13
影响因子：
3.4
通讯作者：
Lenski RE
中科院分区：
文献类型：
--
作者：
Cooper TF;Lenski RE
环境条件影响的拓扑结构的适应性景观，从而不断变化的人口所遵循的轨迹。例如，一个异质的环境可能会导致一个更崎岖的适应景观，使它更有可能复制种群将朝着不同的适应高峰，相对于一个统一的环境。迄今为止，环境变异对进化动力学的影响已经收到相对较少的实验研究。我们报告的结果，从一个实验设计，以测试环境变化的影响，适应和分歧的复制种群的E。杆菌共有42个种群在7个不同的数量，身份和介绍的限制资源的环境制度中进化了2000代。方案分为两组，葡萄糖和麦芽糖单独和组合，或葡萄糖和乳糖单独和组合。糖的组合，同时或作为时间波动的资源制度。这种设计使我们能够比较资源的身份和演示的进化轨迹复制种群的影响。2000代以后，所有种群的适合度相对于共同祖先都有所增加，但程度不同。在葡萄糖中进化的种群改善最少，而在麦芽糖或乳糖中进化的种群在各自的集合中增加最多。人口之间的分歧也不同的制度，在波动的环境中进化的群体比那些面临着恒定的资源方案的变化更高。波动条件下的这种分歧增加1000和2000代之间，一致的复制种群朝着不同的适应性高峰。这些结果支持的假设，环境异质性可以引起更崎岖的适应性景观，这反过来又促进进化的多样化。这些结果还表明，这种影响取决于环境异质性的形式，更大的分歧时，对资源的时间波动，而不是同时呈现。
Environmental conditions affect the topology of the adaptive landscape and thus the trajectories followed by evolving populations. For example, a heterogeneous environment might lead to a more rugged adaptive landscape, making it more likely that replicate populations would evolve toward distinct adaptive peaks, relative to a uniform environment. To date, the influence of environmental variability on evolutionary dynamics has received relatively little experimental study. We report findings from an experiment designed to test the effects of environmental variability on the adaptation and divergence of replicate populations of E. coli. A total of 42 populations evolved for 2000 generations in 7 environmental regimes that differed in the number, identity, and presentation of the limiting resource. Regimes were organized in two sets, having the sugars glucose and maltose singly and in combination, or glucose and lactose singly and in combination. Combinations of sugars were presented either simultaneously or as temporally fluctuating resource regimes. This design allowed us to compare the effects of resource identity and presentation on the evolutionary trajectories followed by replicate populations. After 2000 generations, the fitness of all populations had increased relative to the common ancestor, but to different extents. Populations evolved in glucose improved the least, whereas populations evolving in maltose or lactose increased the most in their respective sets. Among-population divergence also differed across regimes, with variation higher in those groups that evolved in fluctuating environments than in those that faced constant resource regimens. This divergence under the fluctuating conditions increased between 1000 and 2000 generations, consistent with replicate populations evolving toward distinct adaptive peaks. These results support the hypothesis that environmental heterogeneity can give rise to more rugged adaptive landscapes, which in turn promote evolutionary diversification. These results also demonstrate that this effect depends on the form of environmental heterogeneity, with greater divergence when the pairs of resources fluctuated temporally rather than being presented simultaneously.
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影响因子：
8.8
作者：
Habets, Michelle G. J. L.;Rozen, Daniel E.;de Visser, J. Arjan G. M.
通讯作者：
de Visser, J. Arjan G. M.
影响因子：
2.9
作者：
LENSKI, RE;ROSE, MR;TADLER, SC
通讯作者：
TADLER, SC
影响因子：
2.1
作者：
Hadany, L;Feldman, MW
通讯作者：
Feldman, MW
DOI：
10.1098/rspb.1996.0243
发表时间：
1996-12-22
影响因子：
4.7
作者：
Korona, R
通讯作者：
Korona, R
影响因子：
64.8
作者：
Cooper, VS;Lenski, RE
通讯作者：
Lenski, RE