Levis Nicholas A, de la Serna Buzón Sofia, Pfennig David W
Department of Biology, University of North Carolina CB#3280, Chapel Hill, NC, 27599.
Ecol Evol. 2015 Apr;5(7):1405-11. doi: 10.1002/ece3.1448. Epub 2015 Mar 4.
Phenotypic plasticity is commonplace, and plasticity theory predicts that organisms should often evolve mechanisms to detect and respond to environmental cues that accurately predict future environmental conditions. Here, we test this prediction in tadpoles of spadefoot toads, Spea multiplicata. These tadpoles develop into either an omnivore ecomorph, which is a dietary generalist, or a carnivore ecomorph, which specializes on anostracan shrimp and other tadpoles. We investigated a novel proximate cue - ingestion of Scaphiopus tadpoles - and its propensity to produce carnivores by rearing tadpoles on different diets. We found that diets containing tadpoles from the genus Scaphiopus produced more carnivores than diets without Scaphiopus tadpoles. We discuss why Scaphiopus tadpoles are an excellent food source and why it is therefore advantageous for S. multiplicata tadpoles to produce an inducible offense that allows them to better utilize this resource. In general, such inducible offenses provide an excellent setting for investigating the proximate and evolutionary basis of phenotypic plasticity.
表型可塑性很常见，可塑性理论预测生物体通常会进化出机制来检测并响应能准确预测未来环境状况的环境线索。在此，我们在北美锄足蟾（Spea multiplicata）的蝌蚪中对这一预测进行了测试。这些蝌蚪会发育成杂食生态型（即饮食通才）或肉食生态型（专门以无甲目虾类和其他蝌蚪为食）。我们通过用不同食物饲养蝌蚪，研究了一种新的近端线索——摄入北美掘足蟾蝌蚪——及其产生肉食生态型的倾向。我们发现，含有北美掘足蟾属蝌蚪的食物比不含北美掘足蟾蝌蚪的食物产生的肉食生态型更多。我们讨论了为什么北美掘足蟾蝌蚪是一种优质食物来源，以及为什么对于北美锄足蟾蝌蚪来说，产生一种可诱导的攻击性反应从而更好地利用这一资源是有利的。总体而言，这种可诱导的攻击性反应为研究表型可塑性的近端和进化基础提供了一个绝佳的环境。
