Ito Hiroshi C, Dieckmann Ulf
Graduate School of Arts and Sciences, University of Tokyo, 3-8-1 Komaba, Meguro-ku, Tokyo 153-8902, Japan.
Am Nat. 2007 Oct;170(4):E96-111. doi: 10.1086/521229. Epub 2007 Aug 15.
Models of adaptive radiation through intraspecific competition have attracted mounting attention. Here we show how extending such models in a simple manner, by including a quantitative trait under weak directional selection, naturally leads to rich macroevolutionary patterns involving recurrent adaptive radiations and extinctions. Extensive tests demonstrate the robustness of this finding to a wide range of variations in model assumptions. In particular, recurrent adaptive radiations and extinctions readily unfold both for asexual and for sexual populations. Since the mechanisms driving the investigated processes of endogenous diversification result from generic geometric features of the underlying fitness landscapes--frequency-dependent disruptive selection in one trait and weak directional selection in another--the reported phenomena can be expected to occur in a wide variety of eco-evolutionary settings.
通过种内竞争实现适应性辐射的模型已引起越来越多的关注。在此我们展示了，以一种简单的方式扩展此类模型，即纳入一个处于弱定向选择下的数量性状，如何自然地导致丰富的宏观进化模式，包括反复出现的适应性辐射和灭绝。大量测试表明，这一发现对于模型假设的广泛变化具有稳健性。特别是，反复出现的适应性辐射和灭绝在无性和有性种群中都很容易出现。由于驱动所研究的内源性多样化过程的机制源于基础适应度景观的一般几何特征——一个性状中的频率依赖型间断选择和另一个性状中的弱定向选择——预计所报道的现象会在各种各样的生态进化环境中出现。
