昆虫同域物种形成机制及检验

从生物学、生态和遗传的角度阐述昆虫同域物种形成过程中涉及到的可能性机制。昆虫同域种的分化与作用于同域初始种群的歧化选择密切相关,歧化选择间接导致种群生态特征和遗传特征的分化,促进同域近缘种群间的生殖隔离。同域物种形成的过程中涉及到性状替换、性选择、同型交配等机制。寄主专化型多见于昆虫同域种的分化过程中,一般以植食性昆虫为主。有关昆虫同域物种形成的检验机制有多种,归纳起来主要包括同型交配的检验、遗传漂流的量化、遗传分化程度和连锁不平衡(LD)的检测、杂交后代适合度的估算等。目前发现在许多昆虫种类中存在同域物种形成的可能性,但是有关其隔离机制并没有得到充分的解释。

The mechanisms of sympatric speciation in insects and the evaluation

Possible mechanisms of sympatric speciation in insects were discussed in view of their biology, ecology and genetics. Disruptive selection on sympatrically incipient species, which is associated with distinctive divergence on ecological and genetic traits, promoted complete or partial reproductive isolation between sympatrically related populations. Character displacement, assortative mating and sexual selection were involved in the course of sympatric speciation. Host-specific insects were good cases for interpreting sympatric differentiation and most of them were phytophagous. Verifiable criteria for insect sympatric speeiation proposed by some evolutionists and entomologists mainly encompassed the test of assortative mating, quantification of gcne flow, ascertaining the extent of genetic differentiation, estimation of linkage disequilibrium among loci and hybrids fitness, at the like h was possible to demonstrate sympatric speciation in some insects, but further research was needed to elucidate the mechanisms of reproductive isolation.