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.

本研究针对海鸟（鹱形目Procellariiformes与企鹅目Sphenisciformes）及其体表寄生虱（虱目Phthiraptera）的协同演化历史展开了调查。研究分别为海鸟与虱构建了独立的系统发育树：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（BPA）结果支持了普遍存在的共物种形成演化历史（一致性指数=0.84，保留指数=0.81）。研究推断，布鲁克斯简约分析中的同塑性现象由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。通过调和分析，本研究量化了将虱树拟合至海鸟树所需的演化成本。经调和后的TreeMap树推测存在1次宿主切换、9次共物种形成事件、3至4次宿主内物种形成事件以及11至14次分选事件。共物种形成事件的数量显著高于随机预期水平。研究利用序列数据检验了海鸟与虱的演化速率异质性：海鸟树的所有分支均未表现出显著的演化速率异质性，而虱树的部分分支则存在显著演化速率异质性。对共分化节点的分析显示，海鸟与虱发生了同步的共物种形成演化，且虱的演化速率约为海鸟的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Halipeurus属物种的分化早于其当前宿主的演化）。序列数据同样支持了部分被提出的宿主切换事件。本研究结果证实了序列数据与调和分析在解析宿主与寄生物之间复杂演化历史中的应用价值。