Speciation of Phlebotomus sandflies of the subgenus Larroussius coincided with the late Miocene-Pliocene aridification of the Mediterranean subregion

Abstract

The phylogeny and mode of speciation of hlediterranean Plr1ebotontu.r of the subgenus Lnr-iuussiu.c u ere inferred by comparative sequence analyses of a fragment of mitochondria] DNA (Cytochrome b) and of a nuclear gene (Elongation factor alpha). The molecular phylogenies were congruent basally, where their clades matched the species complexes defined by a few genitalic characters of each sex. Reticulate evolution was suggested for the most drrived species complex (Phlebotornus pcm2ciosz1s): the molecular phylogenies were incongruent, and rnitochondrial-marker distribution was consistent Lvith introgressive hybridizations not between sister species but between species whose ranges now overlap or abut. By considering the molecular phylogenies, the mitochondria1 molecular clock and the ecological niches of the species, as \yell as the historical biogeography and palaeoecolo,gy of the blediterraneaii subregon. \ve propose that the derived lineages arose from a sequential series of speciation evcnts associated with habitat shifts promoted by progressive aridification. This 'taxon pulse'-like speciation occurred in the Pliocene, later than previously proposed in a vicariance hypothesis that invoked only tectonic events, but too early for Pleistocene Iceage refugia to have played any role other than the isolation of geographical races. Speciation occurred before the proposed divergence of members of the LxiJhmania donoriani complex and this helped to rule out any vector-parasite co-speciation or co-cladogenesis. 6 '2000 'Ihc Linncan Siicieh of London .ADDITIONAL KE\?VORDS:-Psychodidae phylogeny ~ cpochrome b -Elongation factor alpha -Lrisiinrnnin injknturn -Lpzsiinianiu speciation ~ co-evolution.

Postglacial dispersal ofPhlebotomus perniciosusinto France

“…3) (Rioux & Golvan, 1969) and for the survival of diapausing larvae in the winter (Ready & Croset, 1980). Intraspecific gene introgression could have occurred following postglacial dispersal from Mediterranean refugia, some 12,000 years ago for the last such possible event (Esseghir et al, 2000). For temperate animals and plants, Hewitt (1996Hewitt ( , 1999 proposed three broad patterns of postglacial dispersal into northern Europe from southern refugia.…”

“…This finding was reported, without detailed results or analysis, by Mahamdallie et al (2003). Therefore, mitochondrially, the populations of P. perniciosus from France belonged to the typical lineage (Esseghir et al, 1997(Esseghir et al, , 2000, and not to the Iberian lineage, which contained the haplotypes found in the E_T_TOR population from northeast Spain (Fig. 3).…”

“…evolved (Esseghir et al, 2000). In the present report, isoenzyme and mtDNA markers (Avise, 2000) are used for the first time to characterize French populations of P. perniciosus, in order to investigate their postglacial origins.…”

Sand fly evolution and its relationship to Leishmania transmission

“…The term "evolutionary fit" has been used (Killick-Kendrick 1985), but Esseghir et al (2000) concluded that clear distinctions have not always been drawn between co-association (with the transmission cycle having a distinctive "landscape epidemiology"), co-evolution (e.g. between molecules of the sand fly midgut and the parasite external surface) and vector-parasite cospeciation (or co-cladogenesis).…”

“…infantum, perhaps because some strains of this parasite have been associated with cutaneous rather than visceral human disease. The mode of speciation of Mediterranean Larroussius has recently been inferred from comparative sequence analyses not only of mtDNA but also of a nuclear gene, elongation factor alpha (Esseghir et al 2000). The molecular phylogenies were congruent basally, where their clades matched species complexes defined by a few genitalic characters of each sex.…”