夏天是蝉鸣的季节,人们常常会听到长短不同的蝉鸣声,而最新研究发现,蝉发出的声音不同会导致其分化成不同种类。
英国加迪夫大学的研究人员和葡萄牙同行在新一期《欧洲昆虫学杂志》上发表研究报告说,蝉一生大部分时间都生活在地下,只有夏天才到地面上繁衍后代。雄蝉利用其腹部器官摩擦发出声音,吸引雌蝉前来交配,而雌蝉也只对特定种类的声音做出反应。因此,发出不同声音的蝉之间便形成了“天然的隔离”。
研究人员说,他们对10年来收集的大量地中海蝉的数据进行分析后发现,尽管从外貌和生理结构上看,发出不同声音的蝉之间并没有明显区别,但这种长期“天然的隔离”已经引起了地中海蝉基因的变化,其程度可导致蝉内部分化形成新的种类。
研究人员认为,分析这种仅仅通过声音变化便能逐渐演化出新种类的现象,可帮助人们更深入了解进化论。(生物谷Bioon.com)
生物谷推荐原始出处:
Eur. J. Entomol. 2009, 106(3): 393–403
Patterns of morphometric variation among species of the genus Cicada (Hemiptera: Cicadidae) in the Mediterranean area
SIMOES P.C. & QUARTAU J.A.
Selected populations of five closely related species of the genus Cicada L. were collected mainly on the Portuguese, Greek and Turkish mainland, as well as on several Aegean islands. Ten morphometric traits of external structures and seven of male genitalia were analysed and the results revealed patterns in morphometric variation for each species. Only C. lodosi was always completely discriminated by both character sets and C. barbara by the male genitalia analysis. For the remaining species there was great overlap between the clusters. Body length, of the external morphological structures, and measurements of the pygophore, of the male genitalia, were the best variables for identifying C. lodosi and C. barbara. The present morphometric analyses revealed that divergence in morphology is much less pronounced than the divergence in acoustic signals and DNA. Thus, the congruence between morphological divergence, namely at the level of the external structures, and both behavioural (acoustic) and genetic divergence is quite low.