Recently read Ed Yong's book I Contain Multitudes and I recommend it highly. It is an excellent explainer of the world of the microbiome - a world we know so very little about but also a world that we mess with on a regular basis without proper context for what damage we may be doing to ourselves and our world. We are trying to sterilize our environments but in reality are may be making ourselves more susceptible to more damage and more dangerous things. This book should be MUST READING for any high school biology class.
On Earth we have single celled and multi-celled organisms (like ourselves). This is only possible because of long ago there was a merger between an archaeon and a bacterium. Something that was in Ed Yong's words "so breathtakingly improbable that it has never been duplicated." Another way to describe this could be to say it was a miracle. Maybe even a "let there be life" type miracle.
There's no guarantee that this miracle happened anywhere else in the universe. Not sure Ed Yong thought he was writing a book that might strengthen a person's belief in a higher power but that's what it did for me.
Anyway - I highly recommend I Contain Multitudes (and the videos too!).
