Different but equal: the implausible assumption at the heart of neutral theory.
Different but equal: the implausible assumption at the heart of neutral theory.
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DOI：
10.1111/j.1365-2656.2010.01738.x
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发表时间：
2010-11
期刊：
影响因子：
--
通讯作者：
Turnbull LA
中科院分区：
文献类型：
--
作者：
Purves DW;Turnbull LA
1.中性理论的核心假设是，社区中的所有个体都具有相同的适应度，而不管物种，也不管社区的物种组成。但是，真实的群落是由表现出巨大性状差异的物种组成的;因此，这些差异必须服从完美的适应性均衡权衡，以保持中性。2.在这里，我们解释说，完美的均衡权衡在现实中是极不可能发生的，因为物种之间的适应性平等被破坏：（i）任何偏离的功能形式的权衡离开一个特殊的形式，使平等的适应性;（ii）空间或时间的变化，在性能;（iii）随机物种的性能差异。3.在缺乏传统生态位群落生态学强调的密度依赖过程的情况下，具有少量（i）或（ii）的群落迅速失去性状变异，成为由具有相似性状的物种占主导地位，并且与中性情况相比，表现出明显较低的物种丰富度。社区特征随机种间变异性状（三）失去了所有，但一些偶然的物种。4.因此，中性应被视为，先验，作为一个高度不可能的解释长期共存的可测量不同的物种在生态群落。相反，共存通过生态位结构和密度依赖，是强大的物种差异的基线健身，所以仍然是合理的。5.我们的结论是：（i）共生物种通常会在基线适应性方面表现出很大的差异，（ii）因此，群落必须具有强生态位结构，否则它们将失去性状变异和物种丰富度;（iii）尽管如此，即使在生态位结构很强的社区中，具有相似特征的物种的丰度可能至少部分地自由漂移。
1.The core assumption of neutral theory is that all individuals in a community have equal fitness regardless of species, and regardless of the species composition of the community. But, real communities consist of species exhibiting large trait differences; hence these differences must be subject to perfect fitness-equalizing trade-offs for neutrality to hold. 2.Here we explain that perfect equalizing trade-offs are extremely unlikely to occur in reality, because equality of fitness among species is destroyed by: (i) any deviation in the functional form of the trade-off away from the one special form that gives equal fitness; (ii) spatial or temporal variation in performance; (iii) random species differences in performance. 3.In the absence of the density-dependent processes stressed by traditional niche-based community ecology, communities featuring small amounts of (i) or (ii) rapidly lose trait variation, becoming dominated by species with similar traits, and exhibit substantially lower species richness compared to the neutral case. Communities featuring random interspecific variation in traits (iii) lose all but a few fortuitous species. 4.Thus neutrality should be viewed, a priori, as a highly improbable explanation for the long-term co-occurrence of measurably different species within ecological communities. In contrast, coexistence via niche structure and density dependence, is robust to species differences in baseline fitness, and so remains plausible. 5.We conclude that: (i) co-occurring species will typically exhibit substantial differences in baseline fitness even when (imperfect) equalizing trade-offs have been taken into account; (ii) therefore, communities must be strongly niche structured, otherwise they would lose both trait variation and species richness; (iii) nonetheless, even in strongly niche-structured communities, it is possible that the abundance of species with similar traits are at least partially free to drift.
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影响因子：
5.2
作者：
Fargione, J.;Tilman, D.
通讯作者：
Tilman, D.
影响因子：
4.8
作者：
CHAPIN, FS;SHAVER, GR;LAUNDRE, JA
通讯作者：
LAUNDRE, JA
影响因子：
5.9
作者：
Gotelli, N. J.;McGill, Brian J.
通讯作者：
McGill, Brian J.
DOI：
10.1073/pnas.1033107100
发表时间：
2003-07-22
影响因子：
11.1
作者：
Fargione, J;Brown, CS;Tilman, D
通讯作者：
Tilman, D
影响因子：
8.8
作者：
Clark, JS
通讯作者：
Clark, JS