The article is saying that every person bears some relation to each other, even among distant groups. No further back than 3500 years ago existed a person who was a common ancestor to every currently living human being.

Nnnno; 3500 years ago, there were already clearly-separated groups of humans on different continents.

Perhaps you're off by a 0 or two...?

No, there were fuzzily-separated groups of humans on different continents. There was still some interbreeding across continents.

The Americas may have been clearly separated for a while, but they have done so much interbreeding with people from other continents since 1492, that the common ancestor is more recent than that.

I guess that depends much on whether the claim is that literally every human can draw ancestry back to this common pair, or merely the vast majority, because I'm fairly sure there are still "uncontacted" indigenous peoples in the Americas...

Noah, that you? :D

3500 or 35000?

3500 sounds about right, if we consider only Eurasia. Otherwise, it could be farther back, but possibly not that much further, according to the wikipedia entry for Mitochondiral Eve (look for "most recent common ancestor"):

"Monte Carlo simulations suggest the MRCA was born surprisingly recently, perhaps even within the last 5,000 years, even for people born on different continents."