Gene swapping muddles the history of microbes
Thanks to marriage and birth records, human genealogy is relatively simple. Some people, taking for granted that infidelity hasn't blemished the family history, can trace their genes back hundreds or thousands of years.
Drawing gene-based family trees for microbes offers more of a challenge, biologists are learning. One difficulty stems from microbial infidelity known as horizontal or lateral gene transfer. As scientists tally up all the genes of more and more microbes, they're realizing that bacteria an