What many tend to do as humans is claim anthropomorphise whenever a similarity is pointed out; possibly because many have already made up their mind that humans are different from, and superior to, other animals, so reject any evidence to the contrary, citing instinct or reaction to avoid further consideration. Clearly, if one goes back in time far enough, all plants and animals have the same ancestor; so it would be surprising if those whose mental capacity had most evolved hadn't evolved the same type of emotions as each other, to a greater or lesser extent, as well. The onus is on those who deny this to show it hasn't been so.