DOUBTFUL SPECIES UTILITY. “By comparison, current data suggest a 30 % overlap in gene content between humans and mice. That is, there may be more genetic similarity between a randomly selected human and a randomly selected mouse than there is between two bacterial cells of the same “species.” Clearly, a species concept that encompasses that much genetic variation is not compatible with the species concept as generally applied to multi-cellular eukaryotes.”
https://standardsingenomics.biomedcentral.com/articles/10.1186/s40793-016-0180-8