PRF/J: Molecular Evolution in Strepsirhine Primates

这里的目的是产生和比较线粒体和核DNA序列，以探索链鼻目灵长类动物(例如狐猴和百合)的序列进化的节奏和模式。这项研究的主要目的是检验两个离散的假设：(A)狐猴的分子进化速度是否比懒猴和其他灵长类动物慢？以及(B)狐猴的过渡速度是否较慢？如果能够证明狐猴经历了相对于其他灵长类动物的分子减速，这将表明世代时间不是控制灵长类进化速度的主要变量。分子进化总速率的降低与转换速率的降低相一致，这将暗示一种机制，即总速率可以被减慢或加速。要为统一的分类样本生成大量的线粒体DNA和核DNA序列，将能够比较这两个数据集的进化速度和系统发育。这种方法的一个主要研究优势是，分子进化现象将在强大的系统发生学背景下进行探索。%的结果有望有助于我们了解链鼻目动物的进化，更具体地说，马达加斯加狐猴类，这是生物多样性的例证。此外，这些发现将影响正在进行的关于分子钟真实性的辩论。缺乏共识主导了当前的争论，部分原因是许多研究的系统发育基础很差。这项研究的第三个理由是它对核与线粒体核苷酸序列的评估，这是一种不经常采取的方法。线粒体DNA的大小和核比率差异的估计可能会影响这些基因的系统发育效用。

The intent here is to generate and compare mitochondrial and nuclear DNA sequences in order to explore the tempo and mode of sequence evolution in strepsirhine primates (e.g., lemurs and lorises). The primary objective of this research is to test two discrete hypotheses: (a) do lemurs show a reduced rate of molecular evolution compared to lorises and other primates?, and (b) do lemurs exhibit a slower transition rate? If it can be demonstrated that lemurs have experienced a molecular slowdown relative to other primates, this would indicate that generation time isn't the principal variable responsible for controlling the rate of primate evolution. A reduced overall rate of molecular evolution coincident with a depressed transition rate would be suggestive of a mechanism whereby overall rates can be retarded or accelerated. The large number of mtDNA and nuclear DNA sequences to be generated for a uniform taxonomic sample will enable comparisons of rates of evolution and phylogenies for the two data sets. A prime research strength of this approach is that molecular evolutionary phenomena are to be explored within a robust phylogenetic context. %%% Results are expected to shed light on our understanding of strepsirhine evolution and more specifically Malagasy lemuriforms, which exemplify biological diversity. In addition findings will impact the on-going debate over the reality of a molecular clock. The lack of consensus that predominates the current controversy is partly due to the poor phylogenetic grounding of many studies. A third justification for the study is its assessment of nuclear versus mitochondrial nucleotide sequences, an approach not taken so often. Estimation of the magnitude of mtDNA and nuclear rate differentials may affect the phylogenetic utility of those genes.