Dinosaurs were doomed even before the asteroid

Climate and ecological changes as well as disruption to the food chain were already killing off the dinosaurs.

Dinosaurs were doomed even before the asteroid
Credit: FL Condamine et al., Nature Communications, 2021.
  • Many believe that, absent the giant asteroid strike, dinosaurs would still dominate the earth.
  • But, in the natural history of this planet, there have been five mass extinction events, and most did not require extraterrestrial intervention.
  • A new paper argues that dinosaurs were already headed for extinction and that the asteroid impact 66 million years ago was more of a coup de grâce.

There's a standard paleontological story we tell, and it goes like this: When animals first emerged from their watery genesis to walk on land, they found a world of lush, edible vegetation. Over the course of a few hundred million years (and lots of eating), these animals grew larger and larger until they reached their terrible apex — the dinosaur. These gigantic beasts then dominated the globe.

Flying pterodactyls, sometimes up to ten meters in wingspan, swept up whatever they wanted. Stomping tyrannosaurs would gulp down human-sized prey as an appetizer. A single herbivorous diplodocus might strip a tree clean in a day. Needless to say, a world swarming with terrible lizards left little room for mammals, especially Homo sapiens, to come about.

Deus ex machina

So, thank heavens for… the heavens. Our salvation came from outer space: the asteroid. Or maybe it was a meteor. Or a comet. Whatever it was, a magnificent and colossal cosmic gift hit the earth in modern day Mexico, throwing the climate and environment into chaos, leading to the extinction of the dinosaurs. Then, like a phoenix arising from the ashes, warm-blooded critters emerged from the debris, and the Age of Mammals was born.

It's one of the greatest "what if" stories in all of science. What if the asteroid never hit? Would the dinosaurs still be alive? (And, as a consequence, would we be here?) A new paper argues that dinosaurs were headed to the dustbin of history well before the asteroid came.

The long goodbye

Before humans dominated the planet, species were rarely hunted or killed to extinction by other species. What mostly happened is that organisms died out because they couldn't eat enough.

This could happen in one of two ways: (1) the environment in which a species lives becomes so drastically different that it can no longer find sustenance there, or (2) a rival species comes to dominate the environment, forcing them out. Scientists believe that both were happening to the dinosaurs before the fateful asteroid.

Though the asteroid may have served as a deus ex machina for mammals, it is quite likely that the dinosaurs were doomed anyway.

The arrival of the asteroid 66 million years ago triggered the mass extinction of non-avian (non-bird) dinosaurs, ending the Cretaceous period. The conventional wisdom was that dinosaurs were going strong up until that point. Fossil records depicted a rich variety of species and a diversity suited to a complex food chain. But a recent article thinks that this might not be the whole story. Indeed, it argues that dinosaurs were already in decline for 10 million years.

A cooling planet

Before any asteroid hit the earth, the late Cretaceous period witnessed radical change. The earth's climate has always oscillated between cooler and warmer periods, and it appears that in the millions of years before the dinosaurs went extinct, it was cooling rapidly. (Well, rapidly in geologic terms.) Most of this period had been comparatively warm, with volcanic activity creating greenhouse gases that raised temperatures. But then the earth began cooling.

The late-Cretaceous period was great for hadrosaurs, but most other species of dinosaur were likely on the road to extinction already.

This hit dinosaurs pretty hard. Dinosaurs likely had poor thermoregulatory controls (being "mesothermic," a halfway point between cold- and warm-blooded), which meant that they relied in part on external temperatures to keep their bodies warm enough to function properly. If the temperature did drop as scientists now think, the larger dinosaurs especially would have had no way to regulate their temperature and would have gradually weakened and died.

It is even speculated that the late-Cretaceous period might have resembled a prehistoric Children of Men. Dinosaurs may have controlled the sex of their offspring by the use of temperature, just as crocodiles and turtles do today. If global temperature is dropping, such temperature-dependent sex regulation becomes difficult if not impossible.

Credit: Planetseeker via Wikipedia, licensed under CC BY-SA 4.0

This town ain't big enough

Of course, climate change also would affect vegetation and food availability. The fossil record shows that just before the extinction event, tropical vegetation was giving way to woodland plants. Such a change in flora would mean that a very particular subgroup of dinosaurs would flourish, at the expense of others. And the ones who were predominantly the winners in this were the "hadrosaurs".

Hadrosaurs are basically very large herbivores, and they took to this new environment with gluttonous glee. But, food chains are incredibly complex, and hadrosaurs played a crucial role. Out-eating and out-competing other herbivores, like the triceratops, meant that not only did triceratops die out but so did their carnivorous predators, like tyrannosaurs. No species is an island, and the presence or absence of a keystone species can cause the entire network to break down.

Dinosaurs were doomed anyway

In short, changing climate meant changing vegetation, which in turn caused chaos in the very complicated and sensitive food web. The late-Cretaceous period was great for hadrosaurs, but most other species of dinosaur were likely on the road to extinction already.

None of this is to necessarily say that our familiar paleontological story is nonsense. Geological history is subject to debate and revision. And, even if we accept the dinosaurs were in decline before the asteroid hit, that doesn't detract from the transformative and stark ecological change brought about by a space rock.

The meteorite did cause non-bird dinosaurs to go extinct, but perhaps it wasn't necessary. There have been five major mass extinctions in Earth's history, and the dinosaur-killing asteroid is only one (and it wasn't even the biggest). Many others were caused by geological activity and climate change. Though the asteroid may have served as a deus ex machina for mammals, it is quite likely that the dinosaurs were doomed anyway.

Jonny Thomson teaches philosophy in Oxford. He runs a popular Instagram account called Mini Philosophy (@philosophyminis). His first book is Mini Philosophy: A Small Book of Big Ideas.

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Evolution proves to be just about as ingenious as Nikola Tesla

Credit: Gerald Schömbs / Unsplash
Surprising Science
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Are we really addicted to technology?

Fear that new technologies are addictive isn't a modern phenomenon.

Credit: Rodion Kutsaev via Unsplash
Technology & Innovation

This article was originally published on our sister site, Freethink, which has partnered with the Build for Tomorrow podcast to go inside new episodes each month. Subscribe here to learn more about the crazy, curious things from history that shaped us, and how we can shape the future.

In many ways, technology has made our lives better. Through smartphones, apps, and social media platforms we can now work more efficiently and connect in ways that would have been unimaginable just decades ago.

But as we've grown to rely on technology for a lot of our professional and personal needs, most of us are asking tough questions about the role technology plays in our own lives. Are we becoming too dependent on technology to the point that it's actually harming us?

In the latest episode of Build for Tomorrow, host and Entrepreneur Editor-in-Chief Jason Feifer takes on the thorny question: is technology addictive?

Popularizing medical language

What makes something addictive rather than just engaging? It's a meaningful distinction because if technology is addictive, the next question could be: are the creators of popular digital technologies, like smartphones and social media apps, intentionally creating things that are addictive? If so, should they be held responsible?

To answer those questions, we've first got to agree on a definition of "addiction." As it turns out, that's not quite as easy as it sounds.

If we don't have a good definition of what we're talking about, then we can't properly help people.


"Over the past few decades, a lot of effort has gone into destigmatizing conversations about mental health, which of course is a very good thing," Feifer explains. It also means that medical language has entered into our vernacular —we're now more comfortable using clinical words outside of a specific diagnosis.

"We've all got that one friend who says, 'Oh, I'm a little bit OCD' or that friend who says, 'Oh, this is my big PTSD moment,'" Liam Satchell, a lecturer in psychology at the University of Winchester and guest on the podcast, says. He's concerned about how the word "addiction" gets tossed around by people with no background in mental health. An increased concern surrounding "tech addiction" isn't actually being driven by concern among psychiatric professionals, he says.

"These sorts of concerns about things like internet use or social media use haven't come from the psychiatric community as much," Satchell says. "They've come from people who are interested in technology first."

The casual use of medical language can lead to confusion about what is actually a mental health concern. We need a reliable standard for recognizing, discussing, and ultimately treating psychological conditions.

"If we don't have a good definition of what we're talking about, then we can't properly help people," Satchell says. That's why, according to Satchell, the psychiatric definition of addiction being based around experiencing distress or significant family, social, or occupational disruption needs to be included in any definition of addiction we may use.

Too much reading causes... heat rashes?

But as Feifer points out in his podcast, both popularizing medical language and the fear that new technologies are addictive aren't totally modern phenomena.

Take, for instance, the concept of "reading mania."

In the 18th Century, an author named J. G. Heinzmann claimed that people who read too many novels could experience something called "reading mania." This condition, Heinzmann explained, could cause many symptoms, including: "weakening of the eyes, heat rashes, gout, arthritis, hemorrhoids, asthma, apoplexy, pulmonary disease, indigestion, blocking of the bowels, nervous disorder, migraines, epilepsy, hypochondria, and melancholy."

"That is all very specific! But really, even the term 'reading mania' is medical," Feifer says.

"Manic episodes are not a joke, folks. But this didn't stop people a century later from applying the same term to wristwatches."

Indeed, an 1889 piece in the Newcastle Weekly Courant declared: "The watch mania, as it is called, is certainly excessive; indeed it becomes rabid."

Similar concerns have echoed throughout history about the radio, telephone, TV, and video games.

"It may sound comical in our modern context, but back then, when those new technologies were the latest distraction, they were probably really engaging. People spent too much time doing them," Feifer says. "And what can we say about that now, having seen it play out over and over and over again? We can say it's common. It's a common behavior. Doesn't mean it's the healthiest one. It's just not a medical problem."

Few today would argue that novels are in-and-of-themselves addictive — regardless of how voraciously you may have consumed your last favorite novel. So, what happened? Were these things ever addictive — and if not, what was happening in these moments of concern?

People are complicated, our relationship with new technology is complicated, and addiction is complicated — and our efforts to simplify very complex things, and make generalizations across broad portions of the population, can lead to real harm.


There's a risk of pathologizing normal behavior, says Joel Billieux, professor of clinical psychology and psychological assessment at the University of Lausanne in Switzerland, and guest on the podcast. He's on a mission to understand how we can suss out what is truly addictive behavior versus what is normal behavior that we're calling addictive.

For Billieux and other professionals, this isn't just a rhetorical game. He uses the example of gaming addiction, which has come under increased scrutiny over the past half-decade. The language used around the subject of gaming addiction will determine how behaviors of potential patients are analyzed — and ultimately what treatment is recommended.

"For a lot of people you can realize that the gaming is actually a coping (mechanism for) social anxiety or trauma or depression," says Billieux.

"Those cases, of course, you will not necessarily target gaming per se. You will target what caused depression. And then as a result, If you succeed, gaming will diminish."

In some instances, a person might legitimately be addicted to gaming or technology, and require the corresponding treatment — but that treatment might be the wrong answer for another person.

"None of this is to discount that for some people, technology is a factor in a mental health problem," says Feifer.

"I am also not discounting that individual people can use technology such as smartphones or social media to a degree where it has a genuine negative impact on their lives. But the point here to understand is that people are complicated, our relationship with new technology is complicated, and addiction is complicated — and our efforts to simplify very complex things, and make generalizations across broad portions of the population, can lead to real harm."

Behavioral addiction is a notoriously complex thing for professionals to diagnose — even more so since the latest edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5), the book professionals use to classify mental disorders, introduced a new idea about addiction in 2013.

"The DSM-5 grouped substance addiction with gambling addiction — this is the first time that substance addiction was directly categorized with any kind of behavioral addiction," Feifer says.

"And then, the DSM-5 went a tiny bit further — and proposed that other potentially addictive behaviors require further study."

This might not sound like that big of a deal to laypeople, but its effect was massive in medicine.

"Researchers started launching studies — not to see if a behavior like social media use can be addictive, but rather, to start with the assumption that social media use is addictive, and then to see how many people have the addiction," says Feifer.

Learned helplessness

The assumption that a lot of us are addicted to technology may itself be harming us by undermining our autonomy and belief that we have agency to create change in our own lives. That's what Nir Eyal, author of the books Hooked and Indistractable, calls 'learned helplessness.'

"The price of living in a world with so many good things in it is that sometimes we have to learn these new skills, these new behaviors to moderate our use," Eyal says. "One surefire way to not do anything is to believe you are powerless. That's what learned helplessness is all about."

So if it's not an addiction that most of us are experiencing when we check our phones 90 times a day or are wondering about what our followers are saying on Twitter — then what is it?

"A choice, a willful choice, and perhaps some people would not agree or would criticize your choices. But I think we cannot consider that as something that is pathological in the clinical sense," says Billieux.

Of course, for some people technology can be addictive.

"If something is genuinely interfering with your social or occupational life, and you have no ability to control it, then please seek help," says Feifer.

But for the vast majority of people, thinking about our use of technology as a choice — albeit not always a healthy one — can be the first step to overcoming unwanted habits.

For more, be sure to check out the Build for Tomorrow episode here.

Why the U.S. and Belgium are culture buddies

The Inglehart-Welzel World Cultural map replaces geographic accuracy with closeness in terms of values.

According to the latest version of the Inglehart-Welzel World Cultural Map, Belgium and the United States are now each other's closest neighbors in terms of cultural values.

Credit: World Values Survey, public domain.
Strange Maps
  • This map replaces geography with another type of closeness: cultural values.
  • Although the groups it depicts have familiar names, their shapes are not.
  • The map makes for strange bedfellows: Brazil next to South Africa and Belgium neighboring the U.S.
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