Selv om de endelige beviser ikke er klart fastlagt, og videnskabsmændene ikke er indbyrdes enige, er der i dag mere end blot en mistanke, som resultaterne af forskellige undersøgelser viser.
Even though conclusive proof has not yet been brought forward, and even if there is no consensus among scientists, what we have today is more than mere suspicion, as is shown by the results of various enquiries.