Column: This Earth Day, consider the paradoxical and powerful creature called homo sapiens

Maybe it was the first moon landing; maybe it was the Santa Barbara oil spill, or the sight of an American river so polluted that it caught fire. All of that happened in 1969. The next year, Americans marked the first Earth Day, and the world soon followed. This Earth Day, humanity should be looking as hard at itself, for the human animal has, in our two or three hundred thousand years, unmistakably altered a planet that’s four and a half billion years old.

In his new book “Humanimal: How Homo Sapiens Became Nature’s Most Paradoxical Creature,” the British geneticist and author Adam Rutherford gives our singular species its “dues” — and its don’ts — on why we are the imperfect monarchs of Earth’s animal kingdom.

We humans have spent much of our brief time on this planet trying to make a distinction between ourselves and the other animals. We seem to make it a desperate pursuit. Why?

Well, because we are a completely self-obsessed species — and that is both factual and slightly critical — but with good reason, because we are fascinating, We are fascinated to try and understand how we got to be the way we are, and that we are the only creature that has managed to even question that, to hold ourselves up to the light and ask, are we special?

So it is understandable that we have spent so much time trying to work these things out as human exceptionalism.

But at the same time, we sort of fall into these terrible traps of just being so self-obsessed that we project our own humanity onto the rest of the natural world, and look to nature to explain our own behaviors when in some cases it might help. In other cases, it's completely unrelated.

When it comes to what makes humans distinct, we seem to have drawn lines in the sand that we then have to step back from and draw more lines — for example, the distinction that humans were tool users. Then we observed other creatures using tools.

Because our evolution is that we are part of the animal world. We are an animal. We are classified as an animal, and we're descended from apes and from everything else on that evolutionary trajectory that comes before the apes.

And so we're very biological, but with this shift in our behavior and our thought processes of what we sometimes refer to as behavioral modernity or the cognitive revolution — with that, we evolve new minds and new ways of thinking and new ways of interacting with each other. And in doing so, we set in motion a process which extracts ourselves from nature.

We create gods and we assemble human exceptionalism and we say that we’re specially created. And then Copernicus comes along and says, the Earth is not the center of the universe, and the sun is not the center of the universe comes not long after that.

And Darwin my intellectual hero comes along and says, well, actually we're just another animal. This isn't to be to be misanthropic. I think we're amazing. I mean, I'm a sort of humanist with a small “h.” But at the same time, we're so anthropocentric that we think of ourselves as special when we're not, and miss things that are special about us that we should be really focused on.

What do we miss that is special about us?

I think that this Darwinian phrase — he talks about how we differ by degree and not by kind — and it's a really important phrase because it suggests this continuity with the rest of the natural world. It is true when looking at our own behaviors today and things that we once thought were unique to us that turned out not to be quite so unique.

But on the other hand there are things like speech and language — what we're doing now is so many orders of sophistication greater than anything else we’ve examined so far, any other form of animal or non-animal communication between organisms. It is speech, language, communication — such a complex set of skills we have. My 5-year-old daughter has a much more complicated lexicon than any other creature that existed outside of humankind for the last four billion years.

There's a speech in “Hamlet” that begins, “What a piece of work is man, how noble in reason,” and then, “the beauty of the world, the paragon of animals.”

That’s the opening line of the book. And then Hamlet goes on to say, “And yet, to me, what to me is this quintessence of dust?” That is sort of the key paradox.

What do our fellow animals do that we think of as anthropomorphic? What surprised you about that in your research for this book?

What surprised me most is that so many behaviors that look familiar to us may be unrelated. What was interesting is how often we just conflate those two things. We’ve struggled with understanding animal emotion for a long time now, because our temptation is to anthropomorphize and to say, Well you know that that animal is experiencing the same emotion that I'm experiencing right now.

And then, as science, Darwin wrote about this relationship in a book that hasn't really been cited as much as others which is, “The Expression of the Emotions in Man and Animals.” I think that part of that is because the subsequent reaction to that work was that he had done exactly that: he had over-emotionalized animals.

In fact, as science developed and became more professionalized, we needed to step away and say, Well, we can't know this; we can't know that this this cow is happy or upset that it's being milked.

But at the same time, I actually argue in the book that we've gone too far in the other direction. I've been on the beach today and I was watching a retriever fetch a ball, a tennis ball, from the sea.

Now you'd have to have the hardest, coldest heart to think that that dog was not having a super good time doing that. And yet from a scientific point, a really pure, rationally scientific perspective, it's very hard for us to say that dog is experiencing joy at this time.

So I think we’re really struggling to get into this middle ground of saying that, yeah, animals clearly have emotions, yet we find it difficult to know what those emotions are.

The new standard seems to be theory of mind, a sense of self-awareness in humans that may or may not be shared by animals — creatures reacting to themselves in the mirror knowing it's a mirror, for example.

It’s the idea that, at a certain point during our own development from birth onwards, we begin to recognize that the image that we're looking at when held up to a mirror is ourselves, rather than a picture or a video of another creature. The way we test that is if you put a dot on the forehead of a baby aged a year, on average they will look at it and they won't recognize it, they won’t see that that image is them.

By the time they were 18 months or two [years old], they will touch their own forehand at the dot, recognizing that the image in the mirror is indeed themselves.

Many people have tried to test various animals with this and I’ve got a sort of issue with why you would do that.

Gorillas don't recognize themselves — and so what? It's not an appropriate test for so many of these animals. Gorillas are a good example. Eye contact between two male gorillas is an unabashedly aggressive act, so you see another male gorilla staring you in the eyes, you're going to charge at that mirror and try to smash it up. So why on earth would this be recognition of some kind of self-awareness in a gorilla as it is in us?

People have tried it on dogs too, where dogs don't pass the mirror test. But you know, dogs’ primary form of communication is by smell. You have to devise some kind of smell mirror test in order to consider that self-awareness for dogs.

Applying it to animals just doesn't really say anything about the animals. It says a lot about us.

There's a scene in the film “Inherit the Wind” — a fictionalized recounting of the Scopes trial, the trial of a Tennessee teacher for teaching evolution against the law almost 100 years ago — in which Spencer Tracy, playing a Clarence Darrow-like character, asks what makes us human, that the butterfly is more beautiful and the horse is stronger. He says it’s the ability to think. Is that what we’ve told ourselves for so long?

Again the question arises, is this a difference in degree or of kind? It’s crazy to think that animals don't think — and by the way, I absolutely adore that film, and I love Spencer Tracy in that role; I love Bruce Springsteen’s song about it [“Part Man, Part Monkey”] even more.

You watch a dog quite clearly dreaming of stuff that has happened to it during that day – I don't want to sound like I'm totally flaky about it; I’m a proper scientist and I think about these things hard.

But to imagine that we are the only creature that thinks is – well, it’s misunderstood what thought is, for a start, but it is terribly anthropocentric. And its role in the Scopes monkey trial, whether Darrow actually said that in real life, I do not know. I understand the dramatic point of it, but I think it’s wrong.

The counterpoint in that trial was the question of religion and its influence on how we perceive ourselves. To what extent has religion governed our sense of ourselves as distinct and apart, and fought against the notion of us as another animal?

Well, it's a terrific and terrifically hard question to answer. We often think about religion as being one thing, particularly Christianity being one thing, when in fact Christianity has many different flavors to whoever holds those views.

I think it’s quantifiably different in the States, compared to the U.K., but for the most part people accept that we are evolved from earlier apes, so creationism is not really such a big deal over here. It’s perfectly possible, as several popes have done, to not feel antagonistic about the idea that we are the paradox of being both special and parts of nature, inherently rooted in the same branches of everything in nature.

And I’ve got no beef with that. The founding fathers were mostly Deists, right? Not that Christian compared to many of the American politicians today. So the fact that these things change over time says a lot more about cultures as about our own position.

I don’t get it — I’m really happy being a conundrum. I'm really happy that we are a species that is interesting enough to ask these questions: how do we evolve like this, without needing to have been specially created? But then again, any atheist would say the same thing.

Your book made me think of reverse anthropomorphism, what the animals think of us: the dog who thinks, Look I've trained that creature to throw the ball, and the cat who thinks, Look, I've trained that creature to open a can of food for me!

Cats are the best example of that. We think of them as our pets but clearly the only interaction between cats and humans is that we are their butlers.

The domestication of dogs is a fascinating area because now we're completely codependent. Most dogs only exist because of their interaction with us.

Then again, this is something which is which occurs across the whole of nature. One of the stories I really like in the book was, you think of agriculture as an inherently human behavior, when in fact those leaf-cutter ants that we see on David Attenborough documentaries carrying leaves hundreds of times their own weight — the leaves aren’t the food.

What they're doing is they're taking the leaves as a substrate to grow or produce a fungus on the leaves and the fungus is the food.

They then weed, and they have antibiotics which grow in bacteria on their bodies, on their faces, which only exist in those species. The funguses themselves only exist in the context of their relationship with leaf-cutter ants.

So you’ve got three species there of total mutualism, none of which would exist in their current format unless they had evolved to be mutually beneficial for all three.

We talk about domesticating or taming the natural world — well, ants have been doing this stuff for 20, 30, 40 million years before humans existed. Nature is integrated. Nothing lives apart from anything else.

We're a dominant species but a very short-lived one. As we approach Earth Day, we think of humans as both the ruination of the planet and necessarily its saviors. Where are your thoughts on Earth Day?

I’m an optimist and like I said, I am a humanist with a small “h.” I believe that we are capable of creating such wonders and we are an inherently technological species as well. We messed up this planet and we will fix it, if we could just get our heads together and look above the politics of economics and greed and actually work out that this planet was not gifted to us but we are integrated with it.

One of the errors that people make when they talk about ecological disasters that we have set upon the Earth is that we have killed the Earth.

That is not true. The Earth will continue spinning and life will continue for millions of years after we have removed the ability for us to live on it.

I also think our future lies in the stars and that if my children don't, their children will set foot on other planets. I think, I hope, we don’t make the same mistakes that we did the first time around.

There was one distinction of humanity that was made by an American writer. I'm sure you're familiar with it: Mark Twain said humans are the only animal that blushes, or needs to.

Mark Twain said so many good things. I suppose that’s true, isn’t it? That’s the conundrum, that’s the paradox. We evolved ourselves into a position where we managed to screw things up, but also recognize that we did so.