Ghosts of interaction past 是指现在的看到的一些特性是因为过去的某种互动过程 而演化出来，但是因为现在已经没有处在那些状态中了，所以这些特性就是过去的互动 所留下来的ghost。 在coexistence的互动关系中，ghosts of competition的意思就是指过去曾经两个species 在同一个地点有拥有一样的niche，所以是完全competitive。然而在过程中她们因为演化 出避免竞争的不同niche出来，而且是透过各自的性状的改变去改变了niche (也就是你的 第二个问题，chracter displacement，这是改变的机制)所以逐渐的，竞争消失了。 我们看到的曾经有竞争的证据就是那些ghosts of competition past. 这里是Ghost of competition past的英文定义: Ghost of competition past: The evolutionary avoidance of competition which leads to niche differentiation rather than niche differentiation being the result of present competition 至於character displacement，这里有段英文定义: A pattern of geographic variation, in which a character differs more greatly between two species that share the same geographic location than between two species geographically isolated. The pattern is thought to arise by co-evolution of two species with close resource or habitat requirement, which increases differences between the species. 所以如果我们看到两个竞争物种在某个地区 niche overlap，那麽那个地区可以看到 有些特性其差异大於没有overlap的同物种间的差异。这些差异就是物种为了避免竞争 而逐渐演化出来的新生活模式或者基因上造成的性状改变。如本来大家都是白天觅食， 但是逐渐的其中一个物种开始提早两个小时觅食，最後两个物种完全在时间上隔开了。 这些特性就是character displacement。 这里有段文字叙述可以看: Given enough time, competitors also become genetically more different through evolution. This is called character displacement. It might work like this: the ranges of two very similar species are suddenly overlapping (perhaps because of climate change). Initially there will be strong competition, but small differences in environmental tolerance (e.g. how well they take heat) or food preference (what food items they most like to eat) might allow them to partition resources. As species are now using only a subset of the available habitat or food resource, they may undergo evolutionary change that makes each species better at using that particular subset or “niche”. In time, once close competitors will grow more dissimilar, perhaps to a point where they don’t compete at all (i.e. increases in the density of one species has no consequence for the growth rate of the other). All we might see as observers is the “Ghost of Competition Past” (a phrase coined by Connell), evidence of evolutionary avoidance of competition through character displacement. 如果我上一篇的推文有offend到你的话，真的很抱歉...只是我很不喜欢那种作作业或者 要考试，因为专有名词不会就直接在网路上问问题的情况。 这些专有名词都可以在google上查得到，如果是某个观念不太了解，那应该可以在网路上 写下自己的看法和理解与别人讨论请教，而不是就贴几个字叫其他人讲给你听，或者查给 你看。 : Competition ghost : Character displacement : 是在 Coexistance Factors 里的 Evolutionary factors 看到的 : 谢谢!! --

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