Figure S1. Intraspecific spore viability and geographic origin in four species. The relationship between intraspecific spore viability and geographic origins in the four most common species. The x-axis and y-axis indicate the geographic origins of the two strains used in a hybrid cross. Node color indicates the mean spore viability for crosses between each geographic origin and node size indicates the number of crosses available in the dataset. Nodes along the diagonal indicate crosses within geographic regions. (EUR=Europe, NA=North America, SA=South America, OCEA=Oceania, AFR=Africa).

Figure S2. Intraspecific spore viability and ecological origin in four species. The relationship between intraspecific spore viability and ecological origins in the four most common species. The x-axis and y-axis indicate the ecological origins of the two strains used in a hybrid cross. Node color indicates the mean spore viability for crosses between each ecological origin and node size indicates the number of crosses available in the dataset. Nodes along the diagonal indicate crosses within ecological origins.

Figure S3. Genetic distance between Saccharomyces species Interspecific genetic distances estimated for each pairwise cross using the Genome-to-Genome Distance Calculator 3.0. This formula estimates distance by locally aligning the genomes using BLAST+ resulting in matches called high-scoring segment pairs which represent local alignments that are considered statistically significant. The sum of all identical base pairs over all significant local alignments is then divided by the total alignment lengths. As representatives of each species, we used the same assembled genomes used for the phylogenetic tree (Fig. 1).

Figure S4. Spore viability in interspecific Saccharomyces hybrids Violin plots indicate the distribution of interspecific spore viability for each hybrid cross. Each vertical line indicates an independent cross. The observed distributions may be the result of biased and/or limited sampling of the interspecific diversity. The boxplots indicate the distributions of crosses made with strains within (white) or between (grey) geographic or ecological origins. Asterisk indicates statistical significance using Welch’s t-test (p<0.05).

Figure S5. Interspecific spore viability and geographic origins in all species. The x-axis and y-axis indicate the geographic origins of the two strains used in a hybrid cross. Node color indicates the mean spore viability for crosses between each geographic origin and node size indicates the number of crosses available in the dataset. Nodes along the diagonal indicate crosses within geographic regions. Asterisks indicate crosses with greater than 10% mean spore viability. (EUR=Europe, NA=North America, SA=South America, OCEA=Oceania, AFR=Africa).

Figure S6. Interspecific spore viability and geographic origin in four hybrid crosses. The relationship between interspecific spore viability and geographic origins in the four most common hybrid crosses. The x-axis and y-axis indicate the geographic origins of the two strains used in a hybrid cross. Node color indicates the mean spore viability for crosses between each geographic origin and node size indicates the number of crosses available in the dataset. Nodes along the diagonal indicate crosses within geographic regions. (EUR=Europe, NA=North America, SA=South America, OCEA=Oceania, AFR=Africa).

Figure S7. Interspecific spore viability and ecological origins in all species. The x-axis and y-axis indicate the ecological origins of the two strains used in a hybrid cross. Node color indicates the mean spore viability for crosses between each ecological origin and node size indicates the number of crosses available in the dataset. Nodes along the diagonal indicate crosses within ecological origins. Asterisks indicate crosses with greater than 10% mean spore viability. (EUR=Europe, NA=North America, SA=South America, OCEA=Oceania, AFR=Africa).

Figure S8. Interspecific spore viability and ecological origin in four hybrid crosses. The relationship between interspecific spore viability and geographic origins in the four most common hybrid crosses. The x-axis and y-axis indicate the ecological origins of the two strains used in a hybrid cross. Node color indicates the mean spore viability for crosses between each ecological origin and node size indicates the number of crosses available in the dataset. Nodes along the diagonal indicate crosses within ecological origins.