推 arlix:推薦這篇文章 218.167.165.84 09/23 22:52
推 isotoper:寫的不錯,不懂的確應該先設法自己處理140.112.239.205 09/24 01:14
推 microball:推阿 寫的真好!! 140.109.32.9 09/24 15:51
Ghosts of interaction past 是指現在的看到的一些特性是因為過去的某種互動過程
而演化出來，但是因為現在已經沒有處在那些狀態中了，所以這些特性就是過去的互動
所留下來的ghost。
在coexistence的互動關係中，ghosts of competition的意思就是指過去曾經兩個species
在同一個地點有擁有一樣的niche，所以是完全competitive。然而在過程中她們因為演化
出避免競爭的不同niche出來，而且是透過各自的性狀的改變去改變了niche (也就是你的
第二個問題，chracter displacement，這是改變的機制)所以逐漸的，競爭消失了。
我們看到的曾經有競爭的證據就是那些ghosts of competition past.
這裡是Ghost of competition past的英文定義:
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，這裡有段英文定義:
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.
所以如果我們看到兩個競爭物種在某個地區 niche overlap，那麼那個地區可以看到
有些特性其差異大於沒有overlap的同物種間的差異。這些差異就是物種為了避免競爭
而逐漸演化出來的新生活模式或者基因上造成的性狀改變。如本來大家都是白天覓食，
但是逐漸的其中一個物種開始提早兩個小時覓食，最後兩個物種完全在時間上隔開了。
這些特性就是character displacement。
這裡有段文字敘述可以看:
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到你的話，真的很抱歉...只是我很不喜歡那種作作業或者
要考試，因為專有名詞不會就直接在網路上問問題的情況。
這些專有名詞都可以在google上查得到，如果是某個觀念不太了解，那應該可以在網路上
寫下自己的看法和理解與別人討論請教，而不是就貼幾個字叫其他人講給你聽，或者查給
你看。
: Competition ghost
: Character displacement
: 是在 Coexistance Factors 裡的 Evolutionary factors 看到的
: 謝謝!!
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