One of the most commonly used ways to sell Bodyweight-based exercises is selling it as exercises that the animals do to get strong. It dates back, at least, to Charles Atlas. According to the legend, Atlas watched animals tense their muscles powerfully at zoos as the inspiration for his strength training methods. It must have worked pretty well since Dynamic Tension is probably the best selling mail-order bodybuilding course ever.
The truth probably is more along the lines that Fredrick Tilney came up with much of the course and Charles Roman came up with the story for good ad copy. Still, it doesn't stop many, many others from using the reasoning that their BW-based exercise is more natural because it mimicks movements that animals use to get strong. I usually recognize marketing hype when I see it. Still, I recently read one such web site who yet again claimed to develop strength using animal-like exercises. It got me thinking that maybe this has ad copy has some truth to it.
One thing that I know for a fact that most other primates do on a nearly constant basis is climb things. Indeed, if you want to build some brutal upper body strength, there is nothing better to do than exercises like rope climbing, rock climbing, pull-ups, chin-ups, and monkey bars. They are advanced exercises but I dare anyone to find exercises that will build such latent (and *GASP* functional) strength as primate-like movements. I've repeated it before and I'll say it again, strong people do pull-ups. Strong animals do too.
Another that recently came to my attention is the notion that jogging may be a bad exercise because it might be unnatural. Animals either run at full speed or they walk. They don't typically move at a pace that is in between the two. If you look at the way that your muscles are constructed of fast and slow twitch fibers, there is some good grounds for believing this. Plus, look at people who jog. Often times, they are physically unimpressive and incapable of doing much else than jogging. I've never really enjoyed jogging. I do like to walk and I love sprint-based exercises. I don't feel like my body is missing out on anything. In fact, I tried jogging before work for a couple of weeks and it left me feeling weaker the rest of the day. So, I think that there is some sound thinking to this.
Still, there are a number of things that make this whole concept of doing animal exercises to get animal strength is hype. For one thing, it's just strange to think that animals do something that seems to be a distinctively human behavior like exercise. Plus, animals are mechanically, chemically, and genetically different from us, often times very differently. Some of these animals are built much, much bigger than us. It's not a stretch to believe that they are stronger based on the size difference, not what kind of movement that they're doing.
Then again, one thing that I've learned in life is that you can learned things from the most unlikely sources. Humans have learned many things from watching animals in the past. While it might be good ad copy, I don't think that we can discount the possiblity that we can get powerful from following animal's lead. I can't speak for anyone else but I've gotten stronger by following their examples.