They can survive being entombed for 25 million years in a resin-trapped bee, the conditions inside an operating nuclear reactor, pressures as high as 10 tonnes per square centimetre and depths of 7 km in the Earth's crust. They have existed for most of Earth's history. The number of species is uncountable but is estimated at a billion and more. And although humans depend on the activity of some 30,000 genes encoded in our genome, we are also critically dependent on the presence of up to 4 million genes in upwards of 1,000 species that inhabit the human mouth, intestine, vagina and skin.

Such are the microbes. Nature is pleased to welcome a new sibling that gets to grips with them: Nature Reviews Microbiology (see http://www.nature.com/reviews/micro). In the multidisciplinary spirit appropriate to a Nature title, the journal seeks to enhance communication between the communities of researchers who study viruses, bacteria, fungi and protozoans.

Its relevance can be expected to extend beyond microbiologists. The journal is collaborating with the World Health Organization and others to ensure strong regular coverage of progress in relatively neglected diseases. And there are topics of broad appeal. How much better might we be at cleaning up polluted environments? What can we infer about the last common ancestor of everything alive on the planet? With such questions addressed in forthcoming issues, a broad readership should take note of the new arrival.