Figure 4

Genus: species relative mapping index. Relative index of genes mapped to a taxon at the species level (each box) normalized to genes mapped to a taxon at the genus level (1.0). In the non-industrial populations, there is a significant drop-off in the genes mapped to a taxon at the species level for each gene (FDR-adjusted p-value < 0.001, n = 241), while in industrial populations the rate of mapping is similar at the genus and species level (FDR-adjusted p-value > 0.05, n = 210). Values above 1.0 are due to genes that map to taxa at the species level but not the genus level. This is the result of candidate species (primarily in Lachnospiraceae family) that are annotated at the species level but have a missing annotation at the genus level. This is more common in the industrial populations in our dataset, once again likely due to bias that favors for industrial datasets. FDR adjusted p-values for all statistical comparisons can be found in Data File S1.