All living beings want to dominate, it's genetics: if you dominate you can pass down your genes easier. We definitely came close to being wiped out by bacteria

All living beings want to dominate, it's genetics: if you dominate you can pass down your genes easier. We definitely came close to being wiped out by bacteria. Several times. And no, we don't have more human "strains". Bacteria totally dominated us before antibiotics, and this hard conquered defense wall is already evaporating, and fast.