Evolving to eat air
Israeli scientists have figured out how to convert a heterotroph (an organism that must consume other organisms to survive, like humans) into an autotroph (one that can live off inorganic substances like CO2, as plants do). They did it by gradually starving generations of E. coli bacteria of sugar, while keeping CO2 available. Some of the bacteria evolved mutations that enabled them to survive on the CO2 diet.
> [In all, the evolved bacteria picked up 11 new genetic mutations that allowed them to survive without eating other organisms](https://www.sciencemag.org/news/2019/11/microbe-no-longer-needs-eat-food-grow-thanks-bit-genetic-engineering).
E. coli are also the bacteria most commonly used to create ethanol and many medicines. So a version that eats CO2 and creates valuable products is an amazing development. Kinda like a tree =)