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Large Amounts of Genetic Divergence among Italian Species of the Genus Orchesella (Insecta, Collembola) and the Relationships of Two New Species

✍ Scribed by Francesco Frati; Emiliano Dell'Ampio; Stefania Casasanta; Antonio Carapelli; Pietro Paolo Fanciulli


Publisher
Elsevier Science
Year
2000
Tongue
English
Weight
75 KB
Volume
17
Category
Article
ISSN
1055-7903

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✦ Synopsis


The phylogenetic position of two putative new species of the collembolan genus Orchesella was investigated by comparison with four other Italian species of the genus using a fragment of the mitochondrial gene encoding for subunit I of cytochrome c oxidase (COI). The gene showed the well-known A + T bias, typical of insect mitochondrial DNA, although A + T content was not as high as that observed in species belonging to more derived insect orders. The large number of variable sites in 3rd codon positions (85.2% variable) suggested that these sites contain significant homoplasy due to multiple hits. Despite the lack of morphological differentiation, the COI portion examined shows remarkable levels of genetic divergence between the putative species and their closest relatives. Phylogenetic analysis suggests that one of the putative new species is related to O. villosa, whereas the other is included in a clade with O. cincta and O. ranzii. The species O. chiantica appears to be related to O. villosa, agreeing with previous allozyme data.