Art Bébé says,

‘On microbes, directly lifting from Rob Dunn’s ‘A Natural History of the Future,’ thanking him.

‘Microbes aren’t a key in a bodily lock. That is the wrong analogy. There isn’t a lock, but instead, hundreds of locks, many hundreds or even thousands of ways and contexts in which microbes interact with our bodies. Individual microbe species might play more than one role and hence fit more than one lock. A single role might be filled by more than one microbe species. And which microbial key fits which lock depends on which other species are present on, and in the body. All this is to say that is complicated …. As we consider the future, one of our challenges is that we will need to find a way to continue to pass the species we need to the next generations …. We must carry forward everything, the species we need today, (which we only partially know well enough to list)t, t’he species we will need tomorrow, and the species we could need in the far future in any of the many worlds that might come to be.’