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March 19, 2010
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Dinosaurs are frequently cited as the ultimate exemplars of failure. “Dead as a dinosaur” is now deeply embedded in our vernacular. Yet death for a species, and even for groups of species, is as inevitable as your death. Somewhere around 99 percent of all species that have ever existed are now extinct. The 10 million to 50 million species that comprise the modern day biosphere (the uncertainty due mostly to our lack of understanding of microbial diversity) are but the latest players in a four-billion-year drama—“The Greatest Show on Earth,” to borrow the title of Richard Dawkins most recent book.
Similarly, the event that decimated the dinosaurs about 65.5 million years ago killed off only those dinosaurs like Tyrannosaurus rex and Triceratops horridus alive at the end of the Cretaceous Period (with the exception of some birds, which managed to survive this biologic bottleneck). Dinosaurs existed for 160 million years prior to that doomsday event, birthing a bewildering array of forms that succumbed to the scythe of extinction long before a giant asteroid slammed into the Gulf of Mexico. By comparison, we humans have been around a mere 200,000 years or so, and our small clan of bipedal primate cousins originated about six million years ago. In other words, dinosaurs are a great success story rather than a bunch of prehistoric washouts.
The notion of dinosaurs as failures underscores a pair of conditions that threaten the persistence of humanity: myopia and hubris. Lacking a meaningful sense of deep time, we tend to lump all pre-human life-forms into a single box labeled “extinct.” Virtually blinded by our severe temporal myopia, we ignore the multi-billion-year skein of life-forms, the dramatic comings and goings of organisms through the geologic ages. Meanwhile, our hubris derives from a worldview that transforms other life forms to objects, and places humans not only outside but superior to (nonhuman) nature. While I admit to personal bias on the matter, it’s simply ridiculous to thumb our noses at dinosaurs and laugh derisively at their present-day absence. We might as well speak contemptuously of our great grandparents; after all, they’re no longer with us.
Ecology and evolution are deeply intertwined. Just as the death and decay of organisms provide raw materials for subsequent generations, so too the deaths of species spawn new possibilities for future generations of species. Without extinction, there would be insufficient ecological space for evolution to explore alternative solutions and diversify into new life forms. When initially faced with some change to their native environments, species don’t grimly stay put and evolve into new forms better suited to the transformed conditions. They move, tracking the old habitat. In general, it’s only when the old habitat disappears that species are forced to adapt or die. Mass extinctions—the dying off of multiple, distantly-related lineages over vast areas in a short span of time—occur when one or more external forces wipe out a range of habitats, cutting off opportunities for tracking habitats.
Over the past half-billion years, there have been five major mass extinctions, with the dinosaurs wiped out in the most recent of these. We now face the sixth mass extinction, which threatens to tear apart the fabric of the biosphere, with drastic consequences for most life on this planet, including us. In better times, species losses tick along at a barely discernable rate—perhaps one every five years. At present, somewhere between 50 and 150 species disappear every day, never to be seen again. (Once again, uncertainty in the actual value comes mostly from a lack of basic knowledge about how many species exist.)
This time around, a single species—Homo sapiens—has become the external force driving the decimation of millions of other species. Yes, we are the asteroid now colliding with the planet. The list of anthropogenic factors is all too familiar, among them habitat destruction, overhunting, toxic pollution, and climate change. In particular, the duo of global warming and environmental destruction has eradicated habitats at a pace far exceeding the abilities of many species to track or evolve. At the current rate of extinction, about half of all species alive today may be extinguished by the close of the 21st century, an eco-evolutionary experiment not run since the end of the Cretaceous. Paleontology teaches us that the biosphere takes up to 10 million years to recover from a major mass extinction. So the decisions we make today will have cascading consequences well into the unimaginable future.
Are we (currently) capable of eliminating life on Earth? No. Although this claim is commonly made, life has persisted without hiatus for almost four billion years, and it will be here long after the last human. Life-forms at the small to microscopic end of the size spectrum are the most resilient, some of them hunkered down miles below the Earth’s surface. On the contrary, humanity is far from immune from the profound changes now taking place. Like it or not, we are inextricably embedded into nonhuman nature and dependent on its flows of energy, food, and water for our very survival, as well as for our physical, mental, and emotional health. So we have every reason to raise our awareness of these issues and act accordingly.
Yet, notwithstanding many years of dire warnings from biologists, the sixth extinction has barely touched the collective consciousness of Western cultures. Global warming currently garners the media spotlight, yet recent polls show a significant drop in the numbers of people concerned about even this issue. Despite the bounty of rhetoric, we’re not behaving as if we live on a planet in peril. Consider the recent climate change summit in Copenhagen, where world leaders had a unique opportunity to make history, but failed to reach a meaningful agreement. At this pivotal moment in history, we lack the strength of public opinion necessary to spearhead a World War II-style mobilization to achieve sustainability. Why?
In large part because we’re crippled by an outdated worldview. As a species, we need new glasses capable of curing our temporal myopia and inserting us back into the evolutionary epic—sometimes called the Great Story. We need a mindset that moves beyond our human-centered hubris and inserts us back into the natural world, where we belong. Learning the scientific truth of the matter is part of the solution, but connecting with the nonhuman world through direct experience is equally important. Those of us raised in urban settings may find it tough to establish meaningful connections of this sort, but we can make key steps in the right direction. We can also encourage our children move beyond our limited perspective—to see the world in new, healthier ways that are truer to our nature and critical for a sustainable future.
“But hold on a minute,” I can hear you saying. “If all species go extinct anyway, why should I lose sleep over the current hemorrhaging of life forms?” Ultimately, the answer to this question comes down to ethics, morals, and values. Do we have the right to kill off other species? Do we have the right to rob future human generations of the opportunity to see a whale, a bear, or an elephant in the wild? More to the point for most of us, is it reasonable that we knowingly bring about the downfall of civilization while alternative paths lie before us, untaken? Your call.
ABOUT THE AUTHOR
Scott D. Sampson is a dinosaur paleontologist and science communicator. He served as science advisor and on-air host of the Discovery Channel series "Dinosaur Planet" and is currently serving the same pair of roles in the new hit PBS KIDS series "Dinosaur Train," produced by the Jim Henson Company. He recently completed a book—Dinosaur Odyssey: Fossil Threads in the Web of Life—that is the first general audience review of dinosaur paleontology in a generation. His blog is The Whirlpool of Life. For more information, go to: www.scottsampson.net.
Image of dinosaur skull and Scott Sampson courtesy of Jedrzej Borowczyk.
The views expressed are those of the author and are not necessarily those of Scientific American.
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Unfortunately, no one has ever established what rate of species extinction indicates a healthy ecology. Without the process of extinction, the course of evolution cannot proceed. If the dinosaurs had survived, you wouldn’t be reading this.
Not to imply that the ecology is healthy, but constantly harping on the number of poor species that just went extinct with no historical context and no mention of any new species that has just appeared is meaningless.
Rather than losing valuable species, as far as has actually been determined the unsuccessful adaptations are simply being eliminated in accordance with the normal process of evolution. More information is necessary for proper perspective.
Link to thisAren’t birds, and some lizards direct descendants of dinosaurs? Everything evolves.
As to killing off all species, we can (and may) do that. The earth (rocky planet) will still be here and some species, probably insects, will survive.
Link to thisIf we are talking about a billion years, let’s talk about the next billion. The sun will heat in its lifecycle, there’s bound to be some large asteroids, and the Earth will become more inhospitable to life with or without humans.
Humans developing spaceflight is the "last great hope" of all life on the planet, the only known life there is. If the species are upset at humans for extinctions, perhaps we can "make it up to them" by transplanting life throughout the solar system and beyond. That’s the logical conclusion of this line of thought – to save the only known life in the universe is worth the pain we’ve created, since it is all doomed without us anyways.
Link to thisIf we are talking about a billion years, let’s talk about the next billion. The sun will heat in its lifecycle, there’s bound to be some large asteroids, and the Earth will become more inhospitable to life with or without humans.
Humans developing spaceflight is the "last great hope" of all life on the planet, the only known life there is. If the species are upset at humans for extinctions, perhaps we can "make it up to them" by transplanting life throughout the solar system and beyond. That’s the logical conclusion of this line of thought – to save the only known life in the universe is worth the pain we’ve created, since it is all doomed without us anyways.
Link to thisYes, it makes sense that we ourselves will become an extinct species. And that is natural, even ok. I really hope, however, that intelligence and knowledge about the universe around us does not become extinct. We are building a legacy, a legacy that may be key to life thriving in the universe. The ability contemplate and eventually understand life’s role in the universe and expand beyond the boundaries of earth. To loose that promise along with our demise is terrifying.
Link to this160 million years is time enough for a species to evolve intelligence, grow up, grow old and perhaps die. Not once, but many times over. Perhaps if we make it to the stars we will find our own cousins there.
Link to thisAbout the sun entering the red giant star cycle or another asteroid coming and hitting our planet cant be controlled by us.
We humans with evolved brains and superior knowledge need not be the reason for the extinction of other species.. This is in our hands…We can control this!
Link to thisSome people believe that mythology is facts handed down from generation to generation. If that is true, then according to mythology, there were several more advanced and knowledgable races of people on this planet before the modern human took the reins. Some people even believe that our advanced knowledge is a direct hand-me-down from their adbundant wealth of knowledge that seems to be croping up now more than it ever did before. It seems that Scott D. Sampson has acquired some of their knowledge, no doubt handed down to him through his ancestors’ DNA. He now needs to learn how to access more of the information that was handed down to him and share it with others. We need more people like Scott to bring us up to par on what we already know. When enough of us acquire our ancestors knowledge like Scott has, maybe then we will stop our destruction of our species and the species that is living with us and save our planet.
Link to thisAlthough we humans have so called Intelligence, we are infact incapable of supporting our own future.We pollute, over populate and destroy our own environment.That’s all we are doing and we can do.Flying away to another solar system is just an impossible dream.Man is just another species.Remember that dinos lived a loooooot more than we can imagine.We may be simply too late.
Link to thisReading many of the above comments, there are shining examples of the very myopia and hubris to which the author so eloquently refers. "It’s all going to burn up in a billion years anyway so… why bother (sic) " … have any here a realistic understanding of a hundred years, let alone a thousand, ten thousand, a hundred thousand, a million , ten, a hundred million, let alone a billion? Our own species has come from something if we were to encounter it we would think it an ape to what it is now in only 200,000 years. Humanoid ape like creatures that were ancestors to both ourselves and modern day apes have become what they are in just 10 million years. Dinosaurs were around for 160 million years, and if you accept modern birds as direct descendants as I do, they’ve been around for over 200 million and counting… 500 million years takes you back to a time when reptiles were just beginning to differentiate from amphibians… and so on… a billion years is a million million years… enough time for life to spread out and dominate and get knocked back to bacteria several times. There is no guarantee that intelligence as we define it is what life is going for in it’s unfolding.
Link to thisWe can see what we are doing and to not make changes to save things as they are as much as possible out of some notion that it might inconvenience something as abstract as an economy. People need to get it into their TV addled heads that we and all we call life is here BECAUSE things are the way they are and to allow the very oceans and atmosphere to slowly change their composition and nature due to our unwillingness to deal with our waste puts our very existence at peril. The choice is ours, the technology is here, to not use it and to just go along the way we are is collective suicide, whether we acknowledge it or not.
The main hubris is to think that we humans are special and invincible.
Link to thisWe are just yet another species, a primate with a ridiculously overgrown cortex. If we exceed what the Earth’s ecology can sustain, large numbers will die (and take many other species with them.) We’ve already exceeded what the atmosphere can take long term and have reached peak oil. Almost all large fish in the oceans are gone. What’s next?
@synthiman
I sympathize with your arguments and appeal. I just want to correct a numeric mistake. A billion years is not a million million, as asserted. That makes a trillion. A billion is a thousand million.
Your points are still what they are, but we shouldn’t make basic errors like this. Sorry.
Link to thisWhy are we so blind to the fact that it is our out of control breeding that is causing the human population explosion that is causing these extinctions????
Link to thisGeorge is quite right. Humans who say that the dinosaurs were unsuccessful are not just wrong; the idea is totally ridiculous. The notion comes from human arrogance and ignorance. Dinosaurs ruled the Earth for 150 million or so years and were an outstanding success story – and of course lived in equilibrium with their environment all this time. Don’t forget, either, that in all this reign mammals were an insignificant group peering fearfully from their tiny burrows at their dinosaur masters. It took a huge asteroid impact to wipe dinosaurs – and much of other life from the Earth – and to allow the mammals to emerge, blinking, into a largely empty world.
Let’s look at modern humans. After a mere one fifth of a million years this species has embarked on the wholesale destruction of environments across the world, making our long term survival on this planet as we know it an appalling joke. Now ask yourself, ‘Is this success? How confident are you that we would last the length of time of the dinosaurs?’
Be assured that overall, our species is too stupid, short-sighted and selfish to stop the destruction of the world’s ecosystems. Oh yes, YOU might be smart enough to see it and would, if you could, change things. But you are not in charge: it is our representatives around the world, whether elected or not, who are determining our future and instead of having vision and action, they think only of today or tomorrow and have no planning for the long-term. Don’t overlook either that each country’s economy is arranged so that it can only be sustained by continuous expansion. Since our planet is finite I leave you to think where this must lead.
Further to consider is that many of the politicians around the world are not above acquiring money in less than open circumstances. The upshot this is that commercial interests ultimately determine our future because money is more powerful than politicians integrity.
What are the chances of the policitians getting us out of this path to destruction? Zero. Humans inherited a beautiful planet and will leave it a foul mess.
Happy Easter and best wishes to the life that inherits the planet.
Link to thisCorrection.
Link to thisFor ‘George’ read Scott Sampson, the author of the article.
yet it seems even IF any one person chooses the alternate path there are always hundreds of thousands in the opposition. while it is true we may be on a self-destructive path of civilization. i ask this. is it our destruction because of the greed to know what is in the world that we only think of our needs and not the planets.,or is it because the world’s knowledge has given us greed to know more? as it seems weve put ourselves in a difficult situation. we always will have the choice to change our paths. though it seems ignorances keeps us from the path that is right. the light of truth keeps us from the pain of the right path. do we choose to live in ignorance because the world is too much to understand? or because ignorance is perhaps the most suitable option for the moment? we can ask many questions. but it doesnt matter HOW we get the awnser. everyone just wants the awnser…so before i end my comment i ask this. is life truthfully doomed to fade into oblivian or can it be saved? we have the knowledge we need to save it. but do we have the willpower? do we have the courage? or maybe…we are all doomed to live in fear. that even if we could save ourselves. that if something were to happen. we ourselves wouldnt want to witness our own failures.
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