> Research on Apes became immoral over time

Teaching apes sign language became viewed as immoral?

Do you mean fewer recent examples exist?

"Less recent examples exist" is a positive assertion about the existence of even older examples. The 'less' attaches to the 'recent'. 'Less' can't attach to 'examples' because you can't have 'less examples', because 'examples' is countable.

"Fewer recent examples exist" is a negative assertion about the existence of newer examples. The 'fewer' attaches to the 'examples'.

No, topmost common branch is hominidae

It’s hard to say what’s happening in the video. If the ape is given a command-object-location and must discern all three to correctly complete the task, that would be difficult for a dog. (However, I suspect with as many hours of training as the ape has had, a dog could probably do it. I speculate it would learn all possible trios and remember them as individual commands rather than reconstructing them.)

If the ape is instead given an object and already knows he’s supposed to put it in the fridge, yes, a dog can do that easily. Given a command-object or command-location, a dog can do that as well. A dog can discern “Go bed” or “go kennel” or “fetch ball” or “fetch toy”. “Put ball bed” would be tough. (Dogs won’t “hear” all the cruft words like “the”, they’ll focus in on words they know and puzzle away.)

In any case the degree to which the ape in the video “understands” isn’t clear. It’s possible even with command-object-location test, the ape is doing what I suspect the dog would do. The difference between them might be scale, rather than kind.