Organisms that reproduce asexually have less chances for genetic mutation and genetic drift, meaning that if something is introduced into the environment that causes the organism to be unable to survive, it wont have a variation that might make it possible to live.
The ozonosphere is another term for the ozone layer, which is within the Earth's stratosphere. The ozone layer is responsible for absorbing most of the sun's ultraviolet (UV) radiation, thanks to its high concentration of ozone that is exclusive to this layer.
Answer:
I would say fossil evidence because fossil and rock clues are what led to Wegener's theory of Continental Drift