Isn’t the remarkable thing about humans just how different we are from other creatures? I know what you mean in that we are mammals and we are morphologically similar other primates and so on. But in terms of inner life, and our expression of meaning, is there any other creature that even comes close to humans?
Who’s the scientist who likes to point out that human DNA is only 2% different from other primates, yet in the space of that difference exist Mozart, Michelangelo, and men going to the moon?
Atheist philosopher Raymond Tallis argues strongly that humans are different from other animals in extraordinary ways. See his book Aping Mankind:
https://www.theguardian.com/books/2011/sep/16/aping-mankind-raymond-tallis-review
To me, the uniqueness of humans is what makes me suspect that we really are in some sense “in the image of God”. As it is, we know of no other creature alive that appreciates the vastness and complexity of existence as humans do, or ponders the nature of existence, or all the other many facets of human consciousness that make us unique. Crows are very intelligent, and elephants have seemingly complex social and emotional lives, to give two examples in nature. Nevertheless humans display such range and diversely intricate social and intellectual lives, on a different scale than other animals, that seemingly set us apart from all other creatures.