Humans didn't create cats, dogs, horses, and a few others. These species have been selectively bred for traits that appeal to humans; so there is no surprise that we feel an affinity for them, however we didn't tamper with elephants, whales, dolphins, reptiles, or any of the cute cuddly marsupials humans love.

We've also selectively produced various breeds of chickens, cows, and sheep, but for the most part we value them only for the commodities they provide us.

I don't believe that's true and its also a generalization.

It turns out, from a recent report, that dogs have a muscle that makes their eyes big and cute - and wolves do not. So we have selected them to be creatures we want ...

Yup we look after them

Don’t you mean the ones which man has domesticated? It would be natural to care more for animals which we live with on a daily basis and even share our homes with. I haven’t had the advantage of reading the book in question, so am perhaps speaking out of context...if so please excuse my ignorance if I’ve misunderstood.