This may explain why that fish walked out of the water so long ago.

Earth may have been a cooling tank for spent fuel rods used by an alien civilization. Ocean water levels depleted as a result of the cooling process which exposed the land masses. Radiation from the spent rods did radiating things to the surrounding organisms.

IPSO FACTO, we're a result of the super powers bestowed to our watery ancestors.

*edit /fiction ... because some people took this as super serious