Miyatake Takahisa, Shimizu Toru
Okinawa Prefectural Agricultural Experiment Station, 4-222 Sakiyama-cho, Naha, Okinawa, 903-0814, Japan.
Evolution. 1999 Feb;53(1):201-208. doi: 10.1111/j.1558-5646.1999.tb05345.x.
Reproductive isolation may often evolve as an indirect (pleiotropic) consequence of populations adapting to different environments or habitats. For example, niches that are temporally or seasonally offset can select for organisms with different developmental characteristics. These developmental differences can inadvertently cause reproductive isolation by a variety of means including shifts in mating activity patterns. Here, we show a genetic correlation between a life-history trait (developmental period) and a behavioral trait (time of mating) that causes significant premating isolation in the melon fly, Bactrocera cucurbitae (Diptera: Tephritidae). Fly lines selected for short and long developmental periods differ in their preferred times of mating during the evening. This difference translates into significant prezygotic isolation, as measured by mate choice tests. If the time of mating between two populations differed more than one hour, the isolation index was significantly higher than zero. These indicate that premating isolation can be established if the developmental period is divergently selected for. If such genetic correlations are ubiquitous in many organisms, multifarious divergent selection for life-history traits would often accelerate the evolution of reproductive isolation. We speculate that reproductive isolation may have been evolved via genetic correlations among time-related traits, for example, developmental period and time of mating, as in other organisms.
生殖隔离往往可能作为种群适应不同环境或栖息地的间接（多效性）后果而演化。例如，时间上或季节上错开的生态位会选择具有不同发育特征的生物体。这些发育差异可能会通过包括交配活动模式变化在内的多种方式无意中导致生殖隔离。在此，我们展示了一种生活史特征（发育周期）与一种行为特征（交配时间）之间的遗传相关性，这种相关性在瓜实蝇（双翅目：实蝇科）中导致了显著的交配前隔离。选择发育周期短和长的品系在傍晚时分的偏好交配时间有所不同。通过配偶选择测试衡量，这种差异转化为显著的合子前隔离。如果两个种群之间的交配时间差异超过一小时，隔离指数显著高于零。这些表明，如果对发育周期进行不同方向的选择，就可以建立交配前隔离。如果这种遗传相关性在许多生物体中普遍存在，那么对生活史特征进行多种多样的不同方向选择通常会加速生殖隔离的演化。我们推测，生殖隔离可能是通过与时间相关的特征（例如发育周期和交配时间）之间的遗传相关性而演化的，就像在其他生物体中一样。
