Figure 4. MicrosatellitepopulationgeneticdataforthefiresalamanderintheKottenforst, Germany21,24 analyzed in the framework of allopatric speciation, i.e. a secondary spatial contact of a western pond-breeding lineage and an eastern stream-breeding lineage. The 95% credible cline regions are shown by grey shading. Solid and open round symbolsrepresent larger (��e> 10) andsmall populations (��e ��� 10), respectively. Note that the stream-breeding populations that gave the composite genotype its name are all located in the eastern section of the Kottenforst (six data points indicated with a forward slash (/). One 'intermittent stream' in the western section is indicated by a backward slash. Also note the paucity of data at and around the steepest part of the clines. A ��� loadings on the first PC axis versus geographical distance. The clinecentre is at km 365.3 of the Universal Transverse Mercator (UTM) grid. Cline width is 3952 m. B ��� frequency of the stream-breeding genotype versus distance (after21). Thecline centre is at UTM km 365.1 and the cline widthis 1108 m. For model details see Supplementary Information VI.

Published as part of Arntzen, Jan W. & van Belkom, Joep, 2020, 'Mainland-island' population structure of a terrestrial salamander in a forest-bocage landscape with little evidence for in situ ecological speciation, pp. 1700 in Scientific Reports 10 (1) on page 9, DOI: 10.1038/s41598-020-58551-0, http://zenodo.org/record/5032868