1st European Congress on Odonatology Programme and abstracts

Microevolution through climatic changes? The example of the
expansion of Crocothemis erythraea in Europe
Ott, J. 1 , Sánchez-Guillén 2 , R. A. & Cordero-Rivera 2 , A
1 L.U.P.O Gmb, Friedhofstr. 28, 67705 Trippstadt, Germany
1 Departamento de Ecoloxía e Bioloxía Animal, E. U. E. T. Forestal, Universidade de Vigo, 36005 Pontevedra, Spain
Species may respond to climate change by shifting in abundance or expansions of ranges, by going
extinct, or by adaptive evolution. In the past 2-3 decades Crocothemis erythraea showed a very
remarkable expansion from the Mediterranean to central Europe. In Germany it crossed the entire
country in two decades and now it is also indigenous in the northernmost federal states. Also in other
<strong>European</strong> countries, like the Netherlands, Poland, Czech Republic etc. it showed a clear northward
expansion and in others – like France – it became much more widespread. This expansion could be
seen as a direct effect of climatic changes, as the species followed the increase in temperature.
It is not clear how climate change will affect the level of genetic variation in natural populations.
When new populations are founded by a few individuals, the loss of genetic variation could happen by
genetic drift and/or by the increase of inbreeding coefficients. As the northern populations are now
several hundred to a thousand kilometers away from the original populations it might be, that there
are already also changes in the genetics of the species. To test this hypothesis, we perform
phylogeographic analyses of Crocothemis erythraea over a large part of its geographic range all over
Europe and also in Africa using two mitochondrial genes: Cytochrome b and mitochondrially encoded
NADH dehydrogenase 1.
The sequence of Cytochrome b showed out of 367 bp, there were 15 polymorphic sites revealing a
total of 15 mutations. The total haplotypic diversity was 0.0854. The proportion of individuals with
unique haplotypes in the southern populations (24%) was similar to that of the northern ones (25%).
Haplotypic diversity was comparable between the South (0.833) and North (0.871), and nucleotic
diversity in North was (0.00615) comparable again with the South (0.00595). In ND1 sequence out of
446 bp, there were 9 polymorphic sites revealing a total of 9 mutations. The total haplotypic diversity
was 0.0917. The proportion of individuals with unique haplotypes in South of the distribution range
was (50%) slightly greater than the northern ones (41%). Haplotypic diversity in southern populations
was (0.833) lower than in northern populations (0.924) and the northern nucleotic diversity (0.00486)
was also higher than in the southern populations (0.00374).
Preliminary results showed that genetic diversity was comparable between North and South of the
distribution (for the two genes), not finding evidences of loss of genetic variation. This study on
Crocothemis erythraea reveals the first genetic characterization of a dragonfly expanding its range as
a consequence of climatic change.
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