Horizontal gene transfer (microbiology)

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“One of the most fascinating aspects of microbial life is how they use something called horizontal gene transfer to pass genes back and forth.

Yong: This is one of my favorite aspects of biology, because it is so bizarre and counterintuitive. We are used to the idea of parents passing genes onto their kids, but in the world of bacteria and other microbes, genes are just commodities that can be traded from one individual to another. When those microbes form partnerships with animals [including humans], they can shunt those genes over to us. In doing so, they can sometimes transfer incredible abilities, like the ability to make antibodies, or break into plants and cause agricultural disease.”