Comparative phylogeography of the ants Myrmica ruginodis and Myrmica rubra

Abstract

Aim Here we compare the phylogeographies of the ants Myrmica ruginodis and Myrmica rubra. We test the hypotheses that owing to differences in their cold tolerance and life-history traits, M. ruginodis has less differentiated populations, a weaker phylogeographical structure and some Pleistocene refugia further north than M. rubra.Location The Palaearctic region, from western Europe to Siberia and from Fennoscandia to the northern parts of the Mediterranean peninsulas and Turkey.Methods We sequenced mitochondrial DNA from M. ruginodis samples collected in 53 localities, and used the GenBank sequences of M. rubra individuals from 95 localities, presented in previous work. We studied the genetic diversity of M. ruginodis, the differentiation of its populations, and the geographical distribution and expansion of its haplogroups.Results Populations of M. rubra were genetically slightly more differentiated than those of M. ruginodis, but we did not obtain differences in their phylogeographical structures. Both species had a west-east phylogeographical structure with secondary contact zone in between, and many haplogroups were widely distributed. Main conclusionsThe different life histories of the species (monogynemonocalic versus polygyne-polycalic) seem to have affected population differentiation on a local rather than a phylogeographical scale. Myrmica ruginodis survived the last glaciation in several refugia in the Mediterranean peninsulas and probably in Siberiaas did M. rubrabut also in Turkey. Circumstantial evidence supported the hypothesis of additional, more northerly refugia of the cold-tolerant M. ruginodis close to the southern edge of the permafrost of the Last Glacial Maximum, whereas for M. rubra a northern refugium in western Europe may have also existed. Post-glacial recolonization of both species took place from both the south-west and south-east, and probably also from the east. The origins of the eastern lineages of M. ruginodis were, however, difficult to localize, which stresses the importance of extensive sampling in the east when studying the phylogeography of European taxa.

Chill coma temperatures appear similar along a latitudinal gradient, in contrast to divergent chill coma recovery times, in two widespread ant species

“…An explanation for the patterns of variation in chill coma recovery time along the transect might partly lie in the history of distribution of the species over their ranges. From recent studies of the Myrmica phylogeography, partly based on samples from the same three localities (Leppänen et al, 2013), it follows that the southern population of M. rubra formed through almost a completely separate route of colonization, because it is more closely related to populations in areas southwest of it (the region of the Balkans and southern Carpathians). Therefore, its faster recovery after chill coma might reflect a higher selection for the trait in those montane areas.…”

“…Myrmica rubra and M. ruginodis are common Palaearctic ant species that diverged about 9 million years ago, without further speciation (Jansen et al, 2010); they are relatively abundant over a wide range of latitudes and very often share the same habitats (Leppänen et al, 2013). Myrmica colonies are non-territorial (Savolainen et al, 1989), polygynous, and display a prolonged type of annual cycle (Kipyatkov, 2001), whereby worker ants either grow from eggs to adults within one warm season or delay their development until the next year by entering a diapause at the last (third) larval instar.…”

Cytonuclear incongruences hamper species delimitation in the socially polymorphic desert ants of theCataglyphis albicansgroup in Israel

“…This dependent foundation results in a pattern of isolation‐by‐distance within populations and increases genetic differentiation between populations (Liautard & Keller, ; Clemencet et al ., ; Leppänen et al. , ).…”

Phylogeography of the rare velvety tree ant Liometopum microcephalum (Formicidae: Dolichoderinae)

“…Several ant lineages diverged during the Pleistocene, eventually giving rise to new species (Goropashnaya et al ., , ; Schlick‐Steiner et al ., ; Wysocka et al ., ; Leppänen et al ., ). Liometopum microcephalum arose already during the Pliocene, but the origin of its individual European clades is apparently related to the Pleistocene climatic oscillations.…”

“…Taberlet et al ., ; Fijarczyk et al ., ; Kuznetsova et al ., ), fewer studies dealt with invertebrates (e.g. Rokas et al ., ; Goropashnaya et al ., ; Schmitt et al ., ; Schlick‐Steiner et al ., ; Leppänen et al ., , ). In ants, most studies have been done on a small spatial scale (Pusch et al ., ; Mäki‐Petäys & Breene, ; Wysocka et al ., ) or compared a few distinct populations only (Goropashnaya et al ., ; Sanllorente et al ., ).…”