>>108
here.
>>111
The Altaic languages, specifically the Turkic, Mongolian, and Tungusic families, have had extensive contact throughout history and pre-history.
"Altaic" is probably a good name for an areal grouping of languages (specifically Turkic, Mongolian, and Tungusic languages) that share several features because they've been in contact for millenia. It is probably not a good name for a language family. And it probably should not include Korean, Japanese, Ainu, or Sumerian.
>>109
Historical linguistics and evolutionary biology have borrowed back-and-forth extensively since the late 1700s.
>>110
I'd have to go with an academic pissing contest, as to why it's important.