COLLABORATIVE RESEARCH: Palebiology of Latitudinal Turnover Gradients -- Transoceanic Comparative Analyses

[9905379valentin纵向多样性梯度构成了海洋和陆地系统共有的最显著和最普遍的生物多样性格局之一。然而，这种梯度背后的进化动力学是非常有争议的，部分原因是缺乏经验数据。我们建议以东太平洋、日本和萨哈林岛新近纪软体动物动物群（0 -约1500万年前）为研究对象，对海洋纬度多样性趋势背后的物种进化动态进行比较分析。我们将利用莱利百分比、“反向生存曲线”和物种的地层持续时间，量化沿海岸纬度排列的生物省的物种起源和灭绝率。此外，我们将研究在进化分支内部和分支之间，体型和生活习惯属性的变化如何影响进化速度和物种持续时间。我们将使用东太平洋和西太平洋的动物群作为平行的自然实验，以测试关于多样性控制和沿纬度生物模式组织的假设。这种比较方法将使我们能够排除地质历史、地理和其他相关变量的区域影响，并检验我们结果的普遍性。

9905379ValentineLatitudinal diversity gradients form one of the most dramatic and pervasive biodiversity patterns shared by both marine and terrestrial systems. However, the evolutionary dynamics underlying such gradients are highly controversial, in part because of the lack of empirical data. We propose to undertake comparative analyses of the species-level evolutionary dynamics that underlie marine latitudinal diversity trends using Eastern Pacific, Japanese, and Sakhalin Neogene molluscan faunas (0 - ca. 15 million years ago). We will quantify species origination and extinction rates for latitudinally arrayed biotic provinces along each coast using Lyellian Percentages, "backwards survivorship curves", and stratigraphic durations of species. In addition, we will investigate how variations in body size and life-habit attributes, both within and among clades, influence evolutionary rates and species durations. We will use the Eastern and western Pacific faunas as parallel natural experiments for testing hypotheses on diversity controls and the organization of biotic patterns along latitude. This comparative approach will allow us to factor out the regional effects of geological history, geography and other relevant variables, and to test for the generality of our results.