Dissertation Research: Separating the Effect of History and Ecology on the Bigeography of Day-geckos (Phelsuma): Evidence from mtDNA Analysis

研究了历史、传播和生态对石斑虎岛系群落结构的相对影响。mtDNA的限制性内切酶分析将用于区分这些效应。首先，将该属的系统发育与生物地理学和自然史进行比较。其次，mtDNA的母体遗传模式将用于鉴定最近出现的岛屿上的基因型，并确定这些基因型是原位进化还是代表分散事件。这将提供较低的殖民化率估计。再次，利用母系mtDNA遗传模式，重建P. sundbergi和P. astriata在塞舌尔花岗岩的殖民历史。这些信息将用于确定创始人效应和生态相互作用对产生观察到的体型模式的影响。初步结果表明，塞舌尔群岛最初是由两个远亲祖先“殖民”的。导致阿斯特丽塔的殖民者是线纹塔的近亲；导致松氏疟原虫的居群与马达加斯加疟原虫和阿伯蒂疟原虫有亲缘关系。进一步的工作将包括基础生态学研究，与Anolis辐射的生态学比较，以及与其他分类群的系统发育比较。

The relative effects of history, dispersal and ecology on the community structure of island systems of arboreal day geckos in the genus Phelsuma will be investigated. Restriction enzyme analysis of mtDNA will be used to distinguish between these effects. First, phylogeny of the genus will be compared with biogeography and physical history. Second, maternal inheritance patterns of mtDNA will be used to identify genotypes on recently emerged islands and determine whether these genotypes evolved in situ or represent dispersal events. This will provide a lower estimate of colonization rate. Third, maternal inheritance patterns of mtDNA will again be exploited to reconstruct the colonization history of the granitic Seychelles by P. sundbergi and P. astriata. This information will be used to determine the influences founder effects and ecological interactions have had in producing observed body size patterns. Preliminary results indicate that the Seychelles were originally "colonized" by two distantly related ancestors. The colonist leading to P. astriata was a close relative to P. lineata; the colonist leading to P. sundbergi was close relative to P. madagascariensis and P. abbotti. Further work will include basic ecological studies, ecological comparisons with Anolis radiation, and phylogenetic comparisons with other taxa.