Asked by: Tom Hampton, Townsville, Australia

Evolution is not a ladder, with every organism steadily climbing its way to the top. It’s a cacophony of random mutations where natural selection favours the ones that are slightly better adapted to their local environment. Amoebas are simpler organisms than humans or pine trees, but they aren’t less evolved: they’re the result of the same four billion years of evolution as every other living thing. Amoebas continue to exist because they’re very well adapted to life in each of the many different ecological niches they’ve colonised, from the bottom of the sea to the inside of your skull.

What animals live at the bottom of the Mariana Trench?

Subscribe to BBC Focus magazine for fascinating new Q&As every month and follow @sciencefocusQA on Twitter for your daily dose of fun facts.


luis villazon
Luis VillazonQ&A expert

Luis trained as a zoologist, but now works as a science and technology educator. In his spare time he builds 3D-printed robots, in the hope that he will be spared when the revolution inevitably comes.