Exaggerated male eye span influences contest outcome in stalk-eyed flies (Diopsidae)
Exaggerated male eye span influences contest outcome in stalk-eyed flies (Diopsidae)
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DOI：
10.1007/s002650050613
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发表时间：
1999-09-01
影响因子：
2.3
通讯作者：
Wilkinson, GS
中科院分区：
文献类型：
--
作者：
Panhuis, TM;Wilkinson, GS
男性武器或状态信号的进化被假设为先于女性交配偏好的进化。我们使用了三个物种的马来西亚茎眼苍蝇（双翅目：Diopsidae），以确定是否延长的眼跨度，这是女性在两个性别二型物种的首选，影响比赛结果之间的阶段性男性战斗。极端的性二型性，即大的雄性比雌性拥有更长的眼距，是由Cyrtodiopsis whitei和C。达尔曼尼。与此相反，C. quinqueguttata显示了一个更古老的条件-短，性别单一的眼柄。对20分钟配对比赛的录像带分析显示，具有较大的眼睛跨度和身体大小的男性赢得了更多的战斗中的二态，但不是单态，物种。为了确定是否来自二形物种的雄性直接使用眼距来解决竞争，我们对雄性C。Dalmanni，来自经过30代人工选择以增加或减少眼距的品系。我们发现，眼睛的跨度，独立的身体大小，决定比赛的结果在选定的行男性。此外，在这两个双形物种，平均遭遇持续时间下降的参赛者之间的眼距差异增加，如预期的，如果男性使用眼距来评估对手的大小。遭遇的数量也随着年龄的增长，在二形，但不是单形，物种。选择线男性没有不同的远交男性无论是战斗时间或数量的遭遇。我们的结论是，夸张的男性眼柄进化到影响竞争的相互作用和女性交配的偏好，在这些壮观的苍蝇。
Evolution of male weapons or status signals has been hypothesized to precede evolution of female mating preferences for those traits. We used staged male fights among three species of Malaysian stalk-eyed flies (Diptera: Diopsidae) to determine if elongated eye span, which is preferred by females in two sexually dimorphic species, influences contest outcome. Extreme sexual dimorphism, with large males possessing longer eye span than females, is shared by Cyrtodiopsis whitei and C. dalmanni. In contrast, C. quinqueguttata exhibits a more ancestral condition - short, sexually monomorphic eye stalks. Videotape analysis of 20-min paired contests revealed that males with larger eye span and body size won more fights in the dimorphic, but not monomorphic, species. To determine if males from the dimorphic species use eye span directly to resolve contests, we competed male C. dalmanni from lines that had undergone artificial selection for 30 generations to increase or decrease eye span. We found that eye span, independently of body size, determines contest outcome in selected-line males. Furthermore, in both dimorphic species, the average encounter duration declined as the eye span difference between contestants increased, as expected if males use eye span to assess opponent size. The number of encounters also increased with age in dimorphic, but not monomorphic, species. Selected-line males did not differ from outbred males in either fight duration or number of encounters. We conclude that exaggerated male eye stalks evolved to influence both competitive interactions and female mating preferences in these spectacular flies.