Wissenschaftskolleg zu Berlin, Institute for Advanced Study Berlin, Germany.
J Evol Biol. 2009 Nov;22(11):2332-41. doi: 10.1111/j.1420-9101.2009.01816.x. Epub 2009 Sep 3.
Sympatric speciation remains controversial. 'Sympatry' originally meant "in the same geographical area". Recently, evolutionists have redefined 'sympatric speciation' non-spatially to require panmixia (m = 0.5) between a pair of demes before onset of reproductive isolation. Although panmixia is a suitable starting point in models of speciation, it is not a useful definition of sympatry in natural populations, because it becomes virtually impossible to find or demonstrate sympatry in nature. The newer, non-spatial definition fails to address the classical debate about whether natural selection within a geographic overlap regularly causes speciation in nature, or whether complete geographic isolation is usually required. We therefore propose a more precise spatial definition by incorporating the population genetics of dispersal (or 'cruising range'). Sympatric speciation is considerably more likely under this spatial definition than under the demic definition, because distance itself has a powerful structuring effect, even over small spatial scales comparable to dispersal. Ecological adaptation in two-dimensional space often acts as a 'magic trait' that causes pleiotropic reductions of gene flow. We provide examples from our own research.
同域物种形成仍然存在争议。“同域”最初的意思是“在同一地理区域”。最近，进化论者将“同域物种形成”重新定义为在生殖隔离开始之前，一对群体之间需要完全混合（m = 0.5）。尽管在物种形成的模型中，完全混合是一个合适的起点，但它并不是自然种群中同域的有用定义，因为在自然界中几乎不可能找到或证明同域的存在。这个新的、非空间的定义未能解决关于自然选择是否经常导致地理重叠区域内的物种形成，或者是否通常需要完全的地理隔离的经典争论。因此，我们通过纳入扩散（或“巡航范围”）的种群遗传学来提出一个更精确的空间定义。在这个空间定义下，同域物种形成的可能性远远大于在群体定义下，因为距离本身具有强大的结构作用，即使在与扩散相当的小空间尺度上也是如此。二维空间中的生态适应常常起到一种“神奇特征”的作用，导致基因流的多效性减少。我们提供了我们自己研究的例子。
