For bacteria, it seems that what matters more than your species identity is whether you have specific genes that let you work with other species to form a functioning community.
A new study, looking at the rich communities of bacteria that form on the surface of a common seaweed known as sea lettuce (Ulva australis) and found surprisingly large variations in the 400 or so member species that make up each community.
Despite offering the same habitat, each seaweed played host to many different bacterial species, with only about 15% of species in common from community to community.
Read more at UNSW Sydney