Miyatake Takahisa, Katayama Kohji, Takeda Yukari, Nakashima Akiko, Sugita Atsushi, Mizumoto Makoto
Faculty of Agriculture, Okayama University, Okayama 700-8530, Japan.
Proc Biol Sci. 2004 Nov 7;271(1554):2293-6. doi: 10.1098/rspb.2004.2858.
The adaptation of death-feigning (thanatosis), a subject that has been overlooked in evolutionary biology, was inferred in a model prey-and-predator system. We studied phenotypic variation among individuals, fitness differences, and the inheritance of death-feigning behaviour in the red flour beetle, Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae). Two-way artificial selections for the duration of death-feigning, over 10 generations, showed a clear direct response in the trait and a correlated response in the frequency of death-feigning, thus indicating variation and inheritance of death-feigning behaviour. A comparison of the two selected strains with divergent frequencies of death-feigning showed a significant difference in the fitness for survival when a model predator, a female Adanson jumper spider, Hasarius adansoni Audouin (Araneomophae: Salticidae), was presented to the beetles. The frequency of predation was lower among beetles from strains selected for long-duration than among those for short-duration death-feigning. The results indicate the possibility of the evolution of death-feigning under natural selection.
在一个模拟猎物 - 捕食者系统中推断出了假死（装死）行为的适应性，这一主题在进化生物学中一直被忽视。我们研究了赤拟谷盗（Tribolium castaneum (Herbst)，鞘翅目：拟步甲科）个体间的表型变异、适合度差异以及假死行为的遗传。对假死持续时间进行了十代的双向人工选择，结果显示该性状有明显的直接响应，且假死频率有相关响应，从而表明假死行为存在变异和遗传。对两个假死频率不同的选择品系进行比较，当向甲虫呈现一个模拟捕食者——雌性艾氏跳蛛（Hasarius adansoni Audouin，蜘蛛目：跳蛛科）时，它们在生存适合度上存在显著差异。在选择了长时间假死的品系的甲虫中，被捕食的频率低于选择了短时间假死的品系。结果表明在自然选择下假死行为进化的可能性。
