Arita Héctor T, Vázquez-Domínguez Ella
Instituto de Ecología, Universidad Nacional Autónoma de México, Apartado Postal 70-275, CP 04510, México DF, Mexico.
Ecol Lett. 2008 Jul;11(7):653-63. doi: 10.1111/j.1461-0248.2008.01197.x. Epub 2008 Apr 26.
Several ecological and evolutionary hypotheses have been proposed to explain the latitudinal diversity gradient (LDG), but a general model for this conspicuous pattern remains elusive. Mid-domain effect (MDE) models generate gradients of species diversity by randomly placing the geographic ranges of species in one- or two-dimensional spaces, thus excluding both evolutionary processes and the effect of contemporary climate. Traditional MDE models are statistical and static because they determine the size of ranges either randomly or based on empirical frequency distributions. Here we present a simple dynamic null model for the LDG that simulates stochastic processes of range shifts, extinction and speciation. The model predicts higher species diversity and higher extinction and speciation rates in the tropics, and a strong influence of range movements in shaping the LDG. These null expectations should be taken into consideration in studies aimed at understanding the many factors that generate latitudinal diversity gradients.
人们已经提出了几种生态和进化假说，以解释纬度多样性梯度（LDG），但对于这种显著模式的通用模型仍然难以捉摸。中域效应（MDE）模型通过在一维或二维空间中随机放置物种的地理分布范围来生成物种多样性梯度，从而排除了进化过程和当代气候的影响。传统的MDE模型是统计性和静态的，因为它们要么随机确定分布范围的大小，要么基于经验频率分布来确定。在这里，我们提出了一个简单的LDG动态零模型，该模型模拟了范围转移、灭绝和物种形成的随机过程。该模型预测热带地区具有更高的物种多样性以及更高的灭绝和物种形成率，并且范围移动对塑造LDG有很强的影响。在旨在理解产生纬度多样性梯度的众多因素的研究中，应考虑这些零期望。
