Phylogeography of the Bothrops jararaca complex (Serpentes: Viperidae):: past fragmentation and island colonization in the Brazilian Atlantic Forest
Phylogeography of the Bothrops jararaca complex (Serpentes: Viperidae):: past fragmentation and island colonization in the Brazilian Atlantic Forest
复制标题
DOI：
10.1111/j.1365-294x.2006.03057.x
复制
发表时间：
2006-11-01
影响因子：
4.9
通讯作者：
Bonatto, Sandro L.
中科院分区：
文献类型：
--
作者：
Grazziotin, Felipe G.;Monzel, Markus;Bonatto, Sandro L.
巴西大西洋森林是世界上主要的生物多样性热点地区之一，正受到栖息地严重丧失的威胁。然而，人们对其丰富的特有物种的起源过程知之甚少。在这里，我们介绍了对蝮蛇、长矛头蛇 (Bothrops jararaca) 和该地区特有的两种密切相关的岛屿物种 (Bothrops insularis 和 Bothrops alcatraz) 线粒体细胞色素 b 基因遗传变异的大规模调查结果。系统发育和网络分析揭示了两个得到充分支持的进化枝的存在，表现出南部和北部的分布。这两个系统群的分化时间估计为 380 万年前的上新世，这是一个气候变化剧烈、热带雨林频繁破碎的时期。我们的数据还表明，这两个群体在 5 万至 10 万年前经历了大规模的规模扩张。然而，南部群比北部群表现出更明显的种群规模波动信号，证实了更新世晚期南部森林面积可能遭受更明显减少的证据。岛屿物种 B. alcatraz 和 B. insularis 的多样性非常低，每一种都与位于不同分支的大陆个体共享单倍型。尽管它们具有明显的形态和行为独特性，但这两个岛屿物种似乎起源于最近，并且很可能来自不同的沿海 B. jararaca 种群，可能与更新世晚期或全新世海平面波动有关。
The Brazilian Atlantic Forest is one of the world's major biodiversity hotspots and is threatened by a severe habitat loss. Yet little is known about the processes that originated its remarkable richness of endemic species. Here we present results of a large-scale survey of the genetic variation at the mitochondrial cytochrome b gene of the pitviper, jararaca lancehead (Bothrops jararaca), and two closely related insular species (Bothrops insularis and Bothrops alcatraz), endemic of this region. Phylogenetic and network analyses revealed the existence of two well-supported clades, exhibiting a southern and a northern distribution. The divergence time of these two phylogroups was estimated at 3.8 million years ago, in the Pliocene, a period of intense climatic changes and frequent fragmentation of the tropical rainforest. Our data also suggest that the two groups underwent a large size expansion between 50 000 and 100 000 years ago. However, the southern group showed a more marked signal of population size fluctuation than the northern group, corroborating evidences that southern forests may have suffered a more pronounced reduction in area in the late Pleistocene. The insular species B. alcatraz and B. insularis presented very low diversity, each one sharing haplotypes with mainland individuals placed in different subclades. Despite their marked morphological and behavioural uniqueness, these two insular species seem to have originated very recently and most likely from distinct costal B. jararaca populations, possibly associated with late Pleistocene or Holocene sea level fluctuations.