by Alex Boese
Researchers have also identified meteorites on Earth as having come from Mars, which means that Earth and Mars aren’t isolated from each other. They’ve been exchanging geological material for billions of years – the swapping of material presumably going both ways – thanks to asteroid impacts that blast rocks into space, allowing them to drift from one planet to the other. And, since microbes can survive inside rocks, we have to assume that Earth microbes must have long ago made their way to Mars.
Given this, Levin argues, it would be extraordinary if life didn’t exist on Mars. In fact, a sterile Mars would radically contradict everything we’ve learned in the past few decades about life’s hardiness.
Levin has attracted a small group of scientists to his cause. In 2015, he published an article listing fourteen of them who were willing to declare their belief that his LR experiment found Martian life. He also listed a further fifteen who think his test may have detected life. In this latter column were several prominent scientists, including the physicist Paul Davies and the geologist Robert Hazen.
One of Levin’s most enthusiastic supporters is the Argentinian neurobiologist Mario Crocco, who in 2007 proposed that the life form (supposedly) found by the Viking LR test should be given the scientific name Gillevinia straata, in honour of Levin.
The majority of the scientific community, however, remains unconvinced, and many of Levin’s former colleagues at NASA wish he would just shut up. In 2000, Norman Horowitz, designer of the Viking pyrolytic-release experiment, vented to a Washington Post reporter that, ‘Every time [Levin] opens his mouth about Mars, he makes a fool of himself.’
This isn’t to say that most scientists think Mars is lifeless. Far from it. There’s a popular theory that life may be found on Mars in isolated ‘oases’, or pockets of liquid water underground. But the general feeling is that the Viking results were too ambiguous to offer any concrete proof for the existence of life on the planet.
Of course, the entire controversy could be settled definitively with more missions to Mars designed specifically to look for life, and Levin has been eager for this to happen. He advocates putting a video-recording microscope on a lander so that researchers could visually check to see if there’s anything tiny wriggling around in the Martian soil.
NASA, on the other hand, seems to be in no hurry to settle the debate. It was heavily criticized for having created the Martian-life controversy by sending the experiments to Mars before scientists understood the environment there well enough to interpret the results meaningfully. So, the agency’s strategy is now to proceed slow and steady. The Curiosity rover, for instance, which has been on Mars since 2012, hasn’t done anything to look directly for life. It’s only looked for things that might make life possible, such as the presence of water. Levin has complained that, despite its name, the rover has shown a distinct lack of curiosity.
NASA promises that a future mission to the planet will collect samples of Martian soil, but only so they can be brought back to Earth at a later date and examined at leisure by researchers, and no one knows when that later date might be. It could be decades in the future. Until then, the controversy will persist.
CHAPTER FOUR
The Rise of the Psychedelic Ape
We’ve seen that life established itself on Earth at least 3.7 billion years ago. The earliest form of it about which there’s clear evidence consisted of little more than thin films of single-celled organisms coating the surface of rocks near hydrothermal vents. But one of the most important traits of life is that, over time, it evolves. So, let’s watch in fast-forward as the ancestors of these primitive first cells transform.
For several billion years, the Earth belongs exclusively to the single-celled microbes. They fill the oceans, feeding at first on free-floating organic compounds before learning how to capture the energy of the sun. Eventually, they figure out ways to combine together into multicellular organisms. But it’s not until 550 million years ago that abruptly they explode into a bewildering diversity of animal forms. They’re still in the ocean, but gradually, after another hundred million years, they crawl out onto the land – first as plants, then amphibious creatures, and finally as reptiles that roam far and wide. These reptiles grow into the dinosaurs that rule the Earth for 150 million years, before most of them suffer a cataclysmic end, sixty-five million years ago.
Meanwhile, more humble animals have emerged alongside the dinosaurs: small mammals. And, as the dinosaurs exit the stage, these mammals rise to take their place. One of them in particular is quite peculiar. It’s a small squirrel-like creature that lives in trees.
Fast-forward another forty million years and the descendants of these squirrel-like creatures are still living in trees, but they’ve now grown bigger and are recognizable as primates. Another fifteen million years pass, and some of them are on the ground. And then, about eight million years ago, a remarkable thing happens. A few of them begin to stand on two legs and walk upright.
These, of course, are our direct ancestors: the first hominins. It’s the puzzle of how exactly these creatures appeared and transformed into us that we’ll now examine.
Palaeoanthropology is the branch of anthropology that specializes in addressing this question. These are the researchers who dig up early human fossils and try to tease out clues from them about our evolution. However, these scientists constantly have to fight off the encroachments of outsiders, because how the human species emerged is a topic about which many people have a very strong opinion. It’s these outsiders – some of them amateurs and others from disciplines such as marine biology or genetics – who tend to produce the weirdest theories about our origins.
What if the dinosaurs died in a nuclear war?
Sixty-five million years ago, something killed the dinosaurs. It’s lucky for us that this happened, because, as long as those mighty reptilian predators ruled the Earth, the small mammals that lived alongside them never stood a chance of developing to their full potential. They were too busy trying to avoid becoming dinner. And, if the mammals had remained second-tier residents of the Earth, we would never have come into existence. So, what was it that happened to the dinosaurs? What brought them down?
The leading theory, proposed in 1980 by the father-and-son team of Luis and Walter Alvarez, is that a giant asteroid strike wiped them out. But many other scenarios have been suggested over the years, and at the more unusual end of the scale is the idea that the dinosaurs may have killed themselves in a nuclear war …
The theory that the dinosaurs may have suffered self-inflicted nuclear annihilation occurred, believe it or not, to two different people at around the same time. They were John C. McLoughlin, a writer, artist and author of several popular works about evolutionary biology, and Mike Magee, a retired Yorkshire chemist. McLoughlin came up with the idea first, describing it in a 1984 article in Animal Kingdom magazine, while Magee presented his version slightly less than a decade later in a self-published book titled Who Lies Sleeping: The Dinosaur Heritage and the Extinction of Man.
Although McLoughlin thought up the concept first, there’s no evidence that Magee was aware of this. It really does seem to be the case that both men independently had the same eureka moment, and the arguments they made were very similar. So similar that, for our purposes, we’ll treat them as one joint conjecture, which we’ll call the atomic-dino hypothesis, since neither of them ever coined a term for it.
The phenomenon of two people coming up with the same idea at around the same time is referred to as ‘multiple independent discovery’. A well-known example of it from the history of science is the near-simultaneous but separate discovery of the concept of calculus by Isaac Newton and Gottfried Wilhelm Leibniz in the late seventeenth century. Usually, such an occurrence is a sign that, culturally, something is in the air that has made an idea ripe for being dreamed up, and this was definitely the case for the idea of dino nuclear war.
In 1983, a group of researchers, including Carl Sagan and Paul Ehrlich, had
published an article in Science detailing how a nuclear war would throw huge amounts of sunlight-blocking dust into the atmosphere, thereby triggering a ‘nuclear winter’ that would plunge the surface of the Earth into a deep freeze, making it uninhabitable for years. Before the 1980s, the prevailing wisdom had been that such a war would kill a lot of people, but that a substantial number would survive. The Science article sparked a growing awareness, bordering on mass panic, that a full-scale atomic conflict between the Cold War superpowers could actually bring about our extinction as a species.
This mood of nuclear doom and gloom evidently set McLoughlin and Magee thinking, leading them both to connect the same dots: if a nuclear war could cause a planet-wide extinction, then what if that was what killed the dinosaurs?
Both authors were fully aware of how outrageous such a suggestion sounded. McLoughlin, for instance, emphasized that it wasn’t an idea he actually believed in. He described it as a stray thought that popped into his head late at night that he was unable to get out of his mind. He blamed it on listening to the music of Bartók, that ‘mad Hungarian’. Magee committed himself more fully to the idea, though he also gave himself an out, blaming his pursuit of the concept on the ineffectiveness of the local cider at dulling his fervid imagination. Despite such disclaimers, both men nevertheless went ahead and made the argument in print.
In order for the dinosaurs to have died in a nuclear war, some of them must have been smart enough to build nuclear bombs. There had to have been a dinosaur species that evolved advanced, toolmaking intelligence. This is the first and central pillar of the atomic-dino hypothesis. It asserts that there’s no obvious reason why this couldn’t have happened.
This may sound crazy, but let’s consider what’s required in order for this kind of intelligence to evolve. To answer this question, we only have one example to draw from: our own species. By studying our ancestors, anthropologists have identified some factors that they believe played a crucial role in causing early humans to develop large brains (and, eventually, sophisticated technologies).
At the top of the list are a variety of anatomical features that include opposable thumbs, walking upright and binocular vision (two eyes, with overlapping fields of view, giving depth perception). All of these, in combination, allowed our ancestors to use their hands to manipulate tools, which promoted intelligence.
Living in social groups also placed enormous selective pressure on brain growth, because navigating these relationships is a highly demanding mental task. Finally, and perhaps most unexpectedly, there was our diet. Our ancestors ate meat. It turns out that a species can possess all the previous attributes, but if it lacks an energy-rich diet of the kind that meat most readily provides, it’s very unlikely to ever develop a large brain, because these need a lot of fuel.
So, early humans were group-living, carnivorous bipeds with opposable thumbs and binocular vision. These were the qualities, anthropologists believe, that predisposed them to get smart. Did any dinosaurs share these traits? Yes! McLoughlin offered the example of the deinonychus – the bipedal, pack-hunting predator featured in the movie Jurassic Park, where they were referred to as velociraptors. (The film-makers knew they were using the wrong name, but later argued that velociraptors just sounded better than deinonychus.) These creatures didn’t have opposable thumbs per se, but they had powerful grasping claws, which is the source of their name. Deinonychus means ‘terrible claw’. They definitely had all the other traits.
In fact, there were quite a few dinosaur species with similar characteristics, like the stenonychosaurus. So, based on this list of features, it would be reasonable to predict that at least one dinosaur species should have evolved higher intelligence.
And yet, as far as palaeontologists know, this didn’t happen. The dinosaurs seemed to stand on the cusp of developing big brains, but they didn’t take that next fateful step. Could something else have blocked their progress? Some kind of large-scale environmental condition?
One possibility is that slightly lower atmospheric oxygen levels during the Cretaceous period might have inhibited brain growth, because brains are oxygen-hungry organs. Or perhaps the world of the dinosaurs was too full of dangerous predators. Big brains require more training, which means that infants need to remain dependent on their parents for longer. Human children take well over a decade to mature. In the savage world of the dinosaurs, such a prolonged period of helplessness could have been lethal. Or an even simpler explanation may be that the dinosaurs simply ran out of time. Several palaeontologists have speculated that, given a few more million years, intelligent dinosaurs might have evolved.
The thing is, though, none of these obstacles seem insurmountable. The lack of time, in particular, is questionable. The dinosaurs had 150 million years. How much more did they need?
The atomic-dino hypothesis suggests that, instead of trying to explain why dinosaurs didn’t evolve intelligence despite seeming to possess the necessary prerequisites for it, we should consider the possibility that one species actually did, and we just don’t know about it yet.
This leads to the second pillar of the atomic-dino hypothesis, which makes the argument that the fossil record isn’t complete enough to allow us to say with absolute certainty that brainy dinosaurs, and by extension dino civilizations, never existed. There’s enough wiggle room to create plausible doubt.
Palaeontologists themselves will certainly concede that the fossil record is an imperfect archive. Not everything gets preserved. Using the fossil record to reconstruct the past is a bit like trying to piece together the plot of a movie from a few still frames. You’re never sure how much you’re missing. Characters and entire plotlines may be omitted.
Consider this – the entirety of the fossil record documenting the past six million years of chimpanzee evolution consists of three teeth found in 2005. Three teeth! If, for some reason, chimpanzees had gone extinct a thousand years ago, we probably wouldn’t even be aware that such a species ever existed. The reason for this paucity is because certain environments, such as jungles, don’t preserve bones well. What gets recorded in the fossil record depends entirely on the chance circumstances of where an animal happened to die.
Plus, the further back in time you go, the worse the fossil record gets. If there had been a dinosaur species that experienced rapid brain growth during the final million years of the late Cretaceous period, but it lived for most of that time in a jungle, it’s plausible that we could be entirely ignorant of it.
But wouldn’t an entire civilization leave behind evidence of its existence? Perhaps. Or perhaps not. What would remain of our own civilization in sixty-five million years if we were foolish enough to wipe ourselves out, or were unlucky enough to be wiped out by an environmental catastrophe?
That’s a long time to erase evidence. Earthquakes, floods, tornadoes and hurricanes would rip apart our cities. Sun, wind and rain would erode the rubble. Rising sea levels would drown it. Glaciers would descend from the poles, grinding everything in their path down to a fine dust. Over such a vast expanse of time entire continents would shift and new mountain ranges would rise up. Though it may hurt our vanity to admit, the mark we’ve left on the planet may not be as permanent as we like to think. The Earth could eventually forget us.
There’s an even more unsettling possibility, which forms the final pillar of the atomic-dino hypothesis. It’s possible that evidence of this former dinosaur civilization did survive, but we’re failing to recognize it for what it is. We’re not seeing what’s right before our eyes.
Let’s look at the geological evidence that led researchers to conclude that an asteroid killed the dinosaurs. They found a sediment layer rich in rare elements and heavy metals, as well as chemical signs of massive fires and acid rain at the end of the Cretaceous. It all suggested that some kind of cataclysm occurred at that time, which certainly could have been caused by an asteroid strike. But couldn’t these also be the telltale signs of industrial pollution and nuclear war? The e
xplosion of atomic weapons followed by a nuclear winter could produce effects very similar to an asteroid strike.
There are other clues. It turns out that the dinosaurs didn’t die out abruptly. The fossil record indicates a gradual decline that began around a million years before the end. Something was killing them off before they disappeared completely. It didn’t happen in one moment.
Intriguingly, a similar phenomenon has been occurring during the past 100,000 years of our own era. As our ancestors began spreading out across the globe, equipped with the full mental capacity of modern humans, it seems increasingly clear that they systematically drove to extinction almost every large-sized species they encountered. In North America, they killed mammoths and sabre-toothed tigers; in Australia, the giant kangaroos; in Europe, it was their closest competitor, the Neanderthals. Scholars refer to this mass slaughter as the Anthropocene extinction.
The point is that a slow-moving mass extinction, such as we see in the late Cretaceous, could be evidence of the rise of an intelligent super-predator – a species of dinosaur that far out-performed those around it.
And there’s one more clue in this puzzle, because not all species began going extinct towards the end of the Cretaceous. There were some dinosaurs that survived in substantial numbers right up to the very end. These were the ceratopsians, a group of large herbivorous horned dinosaurs that included the triceratops. What kept them alive, if everything else was dying out?
Again, the history of our own species might offer a possible explanation, because the Anthropocene extinction hasn’t affected all species equally. To the contrary, some species have benefitted greatly from our presence. In particular, various large herbivores, like cows and sheep, have flourished in staggering numbers, even as most other species have been dropping off like flies.