Ok, now I'm pushed into full on "sign me up" just for knowing all that about Neanderthals. 

I never meant to make the claim that full sign language was realistic/accurate,  that was very poorly communicated on my part; I was referring to speech [i]aided[/i] by gesticulating,  not proper sign language specifically.  So,  my bad, I own that. Probably still not accurate,  I don't know. 

Anyway,  I'll keep an eye out for the interest check!