Similarities in unrelated Languages

Language similarities between apparently unrelated languages is quite a prevalent phenomenon, regardless of what the underlying reasons in each case are. Here is a link that clearly shows that totally unrelated languages can have the same words for the same concepts or objects.And how likely are chance resemblances between languages? Quite likely actually. according to this statistical study on the Zompist web site.



The name of water

It comes to my mind a program on the History Channel about the origin of the name Water. The program mentioned the common name of WET, WIT, for "water" in a map with lines coming from China to Germania through Persia. I wonder if the term WED in Arabic is worthy to be linked to that map. Wed in Arabic is the valley where water runs. "Nahr" is another name for the running water, meaning "river". In Morocco the term WED is used in lieu of Nahr. Both terms have the same meaning: "water." In German it is Wasser, and the weather is WETTER. In English it is WET and Water. As if the term water is such an important source of life, that it comes from the deep confines of the human history to run in the mind of all humans with the same intensity.
Can Someone elaborate on this subject?