How did carbon end up being the basis of life on earth?

Because carbon is the most flexible light atom. It has 4 valence electrons. That allows it to bond to up to 4 other atoms in a molecule, more than any other common element except silicon. That opens up a world of possibilities: long chains, saturated and unsaturated carbons, bends and kinks, side chains and branches. read more

Carbon is one of the most common elements in the universe; boron is quite rare. So, if on some primordial planet, carbon-based life and boron-based life both arose, the carbon-based life would rapidly swamp it out of existence by being able to grow, mobilize energy and reproduce much much faster. read more