Speciation in Sapsuckers (Sphyrapicus). II: Sympatry, hybridization, and mate preference in S. ruber daggetti and S. nuchalis
Speciation in Sapsuckers (Sphyrapicus). II: Sympatry, hybridization, and mate preference in S. ruber daggetti and S. nuchalis
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吸管鱼（Sphyrapicus）的物种形成。
DOI：
10.2307/4086817
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发表时间：
1985
期刊：
影响因子：
--
通讯作者：
C. Johnson
中科院分区：
文献类型：
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作者：
N. K. Johnson;C. Johnson
红胸吸管鹬 (Sphyrapicus tuber daggetti) 和红颈吸管鹬 (S. nuchalis) 在俄勒冈州中南部、加利福尼亚州东北部、加利福尼亚州与内华达州边境以及内华达州南部同域分布并杂交。我们研究了这两个类群的重叠分布、杂交性质和择偶偏好。使用“杂种指数”系统，我们确定了 13 个表型类别，代表了典型亲本类型及其杂种中所见的变异范围。异源区域中亲本形式的变异用于区分重叠和杂交区域中的亲本表型与杂种。重叠区域中 145 个筑巢对显示的各种交配类别的百分比表示（同种，75.8%；回交，16.6%；杂种，1.4%；种间，6.2%）用于推断 F 和 F= 代杂种的相对适合度。尽管种间交配产生完全有活力的后代，其数量与预期成正比，但杂交和回交交配显然是不被选择的。我们怀疑Findividuals和各种重组体具有部分不育障碍。在种间交配和回交中，雄性几乎总是 S. r.。达吉蒂（daggetti）或更红的伴侣。这些数据与动态平衡模型（稳定区假说）最为一致，该模型被提出来解释同源区和杂交区，其中来自亲本异源性广泛区域的基因流通过对杂种的选择来平衡。鉴于同种交配的优势，S. r. daggetti 和 S. nuchalis 一起出现，它们被视为生物物种。尽管电泳显示它们的杂交程度低且遗传同一性相近，但这一决定对于这些类群来说是最合适的。 1984年3月9日收稿，1984年9月5日接受。
The Red-breasted Sapsucker (Sphyrapicus tuber daggetti) and Red-naped Sap- sucker (S. nuchalis) are sympatric and hybridize in south-central Oregon, northeastern Cali- fornia, along the California-Nevada border, and in southern Nevada. We examined the overlapping distribution, nature of hybridization, and mate preference in these two taxa. Using a "hybrid index" system, we identified 13 phenotypic classes that represent the range of variation seen in typical parental types and their hybrids. Variation of parental forms in regions of allopatry was used to distinguish parental phenotypes from hybrids in the zone of overlap and hybridization. The percentage representation of various categories of mating (conspecific, 75.8%; backcross, 16.6%; hybrid, 1.4%; and interspecific, 6.2%) shown by 145 nesting pairs in the zone of overlap was used to infer the relative fitness of Fand F= generation hybrids. Although interspecific matings produce fully viable Foffspring in num- bers proportional to expectation, hybrid and backcross matings apparently are selected against. We suspect that Findividuals and various recombinants have partial sterility barriers. In interspecific matings and in backcrosses, the male nearly always is S. r. daggetti or the redder mate. The data agree most closely with the dynamic-equilibrium model (stable-zone hy- pothesis), which has been proposed to explain zones of sympatry and hybridization in which gene flow from the extensive regions of allopatry of parental forms is balanced by selection against hybrids. In view of the preponderance of conspecific matings where S. r. daggetti and S. nuchalis occur together, they are regarded as biologic species. This decision is most appro- priate for these taxa despite their low degree of hybridization and their near genetic identity as shown by electrophoresis. Received 9 March 1984, accepted 5 September 1984.