Many animals are very unrelated, and yet end up looking and acting the same because of living in similar environments. One good example is: dolphins, compared to fish. Bats, compared to birds - or maybe even to each other. Tasmanian Devils, compared to wolves. There are many, many examples of similar morphology in unrelated species. It is something extremely important to remember when studying biology and evolution. (It also helps to keep this rule in mind when studying sociology or politics). Here's an interesting site to explore...
Cracked: 10 Animals You Won't Believe Are Closely Related
Standford Encyclopedia: The Genotype/Phenotype Distinction
You may see some insect that resembles a dangerous wasp, yet it is only aping a wasp in appearance, so as to keep birds from eating it. Insects, animals, and plants mimic other beings or conditions in their environment, as if they are all part of some infinite roaming eye, by the coincidences of natural selection. (Similarly, animal languages in the jungle are widely understood, if not shared). This establishes the so-called, "balance of nature," when, in fact, dynamic change and punctuated equilibrium occur in the bigger picture, as does climate change and environmental adaptations.
So, differing species may be similarly moulded by their similar environments. Some animals, like cuckoos, mocking birds and parakeets, may ape others, to gain acceptance, despite being genetically different. Mammals are notorious for adopting, or even loving, very genetically different mammals, despite the rule to, "be kind to same-DNA, above all," (as opposed to being indiscriminately helping or altruistic).
We humans are at the pinnacle of the food chain mountain, and we have generally conspired together, helping ourselves. We have generally been kind to our own DNA, while mowing over the rest of creation. Ever following in the wake of this blood-and-chlorophyll-shed, there always emerges a contrary band of humans advocating for the rights of fish, or trees, or aborigines, or cattle, or foxes - because we CARE. Because, are we all so different, after all? What is the difference between a whale and a microbe, when both hold life?
And yet, we also go to war with each other based on how each clan parts its hair. Egads! What a difference! It is like we are each from vastly different corners of the universe, the way we differently butter our bread! A Moslem says, "God," and a Christian says, "God," and somehow this gross disparity eventuates in world war three. In fact, it is this constant slashing at each other, and this slashing at the Earth, combined with our ever endearing love of self and all, which expands our population above all others, in perpetual madness.
One day, you may see, walking down the street, what appears to be your Doppelgänger. Looks just like you. Acts like you. Sits in the same coffee shop. Will you sit down and chat, and love this person, because his or her DNA is virtually yours? Will you shower upon this person all the love and expectations you have for yourself? What about all your self-limitations, doubts and hatreds?
Or will you be suspicious? Will you be angry that this Other is stealing attention - your social identity? If you put them up - would they steal your clothes, your food, your friends?! Would they be so similar, that you would become so bored with their predictable sameness, that you would both just disappear into some foggy blur of depression?
Or, would they be so different, since they are there and you are here, that jealousy will swell up in you all the more violently, that you would want nothing other than to kill this identical clone, because it is so vastly, vastly not you? Would you envy this photocopy so much, apart from you, that you would want nothing more than to become it, replace it, put your body and life exactly in the space which it inhabits? For, do you not have that right? Has not a crime been committed here - a case of identity theft?
This is how we are as human animals. We hate that what is genetically different from us, especially if it might eat us, or interfere with our easy day. But, we love and reward our genetically related kin, and clan, and even our religion - albeit full of unrelated cuckoos and mocking birds - other races and kinds. For those whom our words call, "Same," we will go to war, we will perform heroic acts of altruism, we will grow our children to do the same for them, or even to be sacrificed for them.
So, why not do the same for your identical twin from another land? You would think you would - and you would - but you can't. In human animals, there is always this tension of how to regard another being, whether it is 100% identical, or 100% different, even while the wider rules are being applied. That means that in every human animal, there is a continuing conflict between the conscious and the subconscious/id, with each sometimes being supplanted by the other.
So, you might go through life, following all the golden, wider rules, only to find that all your so-called friends have mainly done nothing for you but dig you an early grave. Unless you understand this natural paradox in human nature, which is related to 'physics', you will innocently and ignorantly become depressed or sick, and indeed die young. Or, if you only believe the opposite, that all are inclined to kill you, (the psychopath), then you will find your own hell awaiting you.
What if I told you that your Doppelgänger, walking down the street - the one you'd be so wont to love, yet so wont to kill - was not a human at all? Not even an animal. What if I told you that that living image of you was a machine - a computerized android?
Is that different enough for you to leave it alone, or love it?
Is that same enough for you to love it, or leave it alone?
How do you, at the same time, KNOW the difference of its mechanical nature, and yet NOT involve yourself in emotional antipathy towards it, an inert object?
How do you, at the same time SEE the exact similarity in its physical form, and behaviours, and yet NOT involve yourself in empathy?
Conflicted feelings are our greatest accomplishment.
Bat shit crazy.