Table 2. Summary of the three transects across contacts between evolutionary lineages in M. arvalis.

Transect	Lineage transition	First/last locality	Length (km)	Localities	N (Cytb)	N (SMCY11)
Jura	Western–Central	Cerniébaud/Les Cullayes	51	40	281	126
					(178 W–103 C)	(36 W–90 C)
Grisons	Central–Italian	Diepoldsau/Jochalp	71	26	287	104
					(133 C–154 It)	(90 C–14 It)
Valais	Central–Western	Aigle/Villa	159	23	138	55
	Western–Italian				(40 C—79 W—19 It)	(12 C—6 W—37 It)

Positions of transects and sampling localities are shown in Figure 1. The Valais transect along the Rhone valley contains a double transition from the Central (C) through the Western (W) to the Italian (It) lineage. Sample sizes are given for mtDNA (cytb) and Y-chromosomal sequences.