How can something be grammatically meaningless? Further, because you're not able to understand the semantic meaning of a phrase does not mean it has no semantic meaning. I don't understand German--is German semantically meaningless?
> I am all for using a more casual voice
> I am against colloquial, spoken styles slipping into written word
Are these not contrary to one another?
Also, conflating dialects, verbal fillers, and languages is asinine and you know that is not what my original point was. Writing casually about an expert domain is like, uh, different than writing spoken word as written, ya know?
Your argument supporting your prior assertion that "the sentence has meaningless grammar/syntax" is that... if you remove part if it, the sentence ceases to make sense?
Their sentence isn't semantically ambiguous. You may not understand the meaning of their sentence, but your experience is not everyone's experience. The word "uh" in the quoted sentence serves a particular purpose--it's an emphasis of the ridiculousness about how little we know with respect to the animals. Moreover, it's a very concise way of communicating that emphasis.