Data from: Seabird and Louse Coevolution: Complex Histories Revealed by 12S rRNA Sequences and Reconciliation Analyses

We investigated the coevolutionary history of seabirds (orders Procellariiformes and Sphenisciformes) and their lice (order Phthiraptera). Independent trees were produced for the seabirds (tree derived from 12S ribosomal RNA (rRNA), isozyme, and behavioral data) and their lice (trees derived from 12S rRNA data). Brookâ s parsimony analysis (BPA) supported a general history of cospeciation (consistency index = 0.84, retention index = 0.81). We inferred that the homoplasy in the BPA was caused by one intrahost speciation, one potential host switching and eight or nine sorting events. Using reconciliation analysis we quantified the cost of fitting the louse tree onto the seabird tree. The reconciled TreeMap tree postulated one host switching, nine cospeciation, three or four intrahost speciation and 11 to 14 sorting events. The number of cospeciation events was significantly more than would be expected due to chance. The sequence data were used to test for rate heterogeneity for both seabirds and lice. The seabird tree showed no significant rate heterogeneity over all of its branches whereas part of the louse tree did show rate heterogeneity. An examination of the codivergent nodes revealed that seabirds and lice have cospeciated synchronously, and that lice have evolved at about 5.5 times the rate of seabirds. Sequence data supported some of the postulated intrahost speciation events (Halipeurus pre-dated the evolution of their present hosts). Sequence data also supported some of the postulated host-switching events. These results demonstrate the value of sequence data and reconciliation analyses in unraveling complex histories between hosts and their parasites.本研究探究了海鸟（包括鹱形目（Procellariiformes）与企鹅形目（Sphenisciformes））及其体表虱（虱毛目（Phthiraptera））的协同进化历史。研究分别构建了海鸟与虱的独立系统发育树：海鸟树基于12S核糖体RNA（rRNA）、同工酶及行为学数据构建，虱树则基于12S rRNA数据构建。布鲁克斯简约分析（Brooks Parsimony Analysis, BPA）结果表明，二者整体呈现协同成种的进化历史，其一致性指数为0.84，保留指数为0.81。研究推断，布鲁克斯简约分析中出现的同塑性现象，由1次宿主内物种形成、1次潜在宿主切换以及8至9次分选事件所导致。本研究通过和解分析，量化了将虱系统发育树拟合至海鸟系统发育树所需的进化代价。经TreeMap软件得到的和解树结果显示，存在1次宿主切换、9次协同成种、3至4次宿主内物种形成以及11至14次分选事件。协同成种事件的数量显著高于随机过程预期的水平。研究利用序列数据，分别检验了海鸟与虱的序列进化速率异质性：海鸟系统发育树的所有分支均未表现出显著的速率异质性，而虱系统发育树的部分分支则存在显著的速率异质性。对共分化节点的分析表明，海鸟与虱实现了同步协同成种，且虱的进化速率约为海鸟的5.5倍。序列数据支持了部分被提出的宿主内物种形成事件，例如哈利佩虱属（Halipeurus）的分化早于其当前宿主的演化历程；同时，序列数据也支持了部分被提出的宿主切换事件。上述研究结果证实了序列数据与和解分析在解析宿主与寄生物间复杂进化历史中的应用价值。