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Coelomactra antiquata is a commercially important bivalve species, but has been suffering from severe population decline due to over-exploitation
and the deterioration of environmental conditions. Previous genetic survey of C. antiquata conducted with allozymes combined with morphology revealed high levels of genetic differentiation between northern and southern
populations which suggests a cryptic species might exist in C. antiquata. To test this hypothesis, amplified fragment length polymorphisms (AFLPs) and 16S rRNA gene sequence were used to re-evaluate
the spatial genetic structure of six populations of C. antiquata along the coast of China. Both genetic markers display a sharp genetic break between the four northern populations (northern
lineage) and two southern population (southern lineage). Large numbers of private alleles (AFLP) were found within the northern
or southern populations and a deep divergence of about 6.5% in 16S rRNA gene sequence between the northern and southern lineages
suggests the occurrence of potential cryptic or sibling species of C. antiquata. Applying previously published rates of mutation, divergence between the two lineages is estimated to have occurred approximately
3 million years ago and may be due to allopatric isolation during the middle Pliocene times. While no genetic differentiation
was found within the northern or southern populations in both AFLP and 16S mtDNA markers, the results indicate that the northern
and southern lineage should be managed separately and any translocation between the two areas should be avoided. 相似文献
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光污染防治立法的研究及探讨 总被引:1,自引:0,他引:1
目前,光污染这种新型的环境污染,已成为一个必需正视的环境问题。为了更为有效地防治光污染,保护公众的环境权益,中国急需建立光污染防治法律体系。采用符合本国国情的立法模式,建立完善的监管体系,制定具体明确的光污染防治标准等将是中国光污染防治法律体系建立的核心内容。本文阐述了光污染的概况,介绍了国内外光污染防治立法现状,前瞻性地提出以经济和生态的可持续发展为指导思想,采取预防性原则从环保和法律的角度出发,建立符合中国国情的光污染防治体系,全面防治光污染的建议。 相似文献
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