by Alex Boese
What if something similar was occurring in the late Cretaceous? What if the ceratopsians survived in such high numbers because a brainy species of dinosaur was farming them for meat? What if the intelligent dinosaurs had a taste for triceratops burgers?
Brainy, nuke-building dinosaurs? Triceratops burgers? Admittedly, all this might be a hard pill to swallow. Certainly, there are no palaeontologists who take any of it seriously.
Yes, the effects of an asteroid impact might vaguely resemble those of a nuclear war from a vantage point of sixty-five million years. But surely some fragment of dinosaur technology would have survived if it ever existed. A piece of a dino-gun or a dino-engine. A dino-nuke! But there’s nothing.
There’s also the Chicxulub impact crater, off the coast of Central America, which is hard to explain away. It was identified in the early 1990s as the site where the dinosaur-killing asteroid probably landed. In other words, scientists are pretty sure that something big hit the Earth, and, if this is the case, there’s no need to conjure up a nuclear war in addition to account for the extinction of the dinosaurs.
The atomic-dino hypothesis does, however, touch on a larger issue, which may be a reason for not dismissing it as entirely frivolous. It’s the question of why we’re the only species to have ever evolved advanced, tool-wielding intelligence. One would think that this is such a useful ability to possess that evolution, in its constant search for competitive advantage, would have hit upon it more than once. Other complex traits, such as flight and eye lenses, have evolved independently multiple times. And yet, we’re apparently the only species that has ever managed the trick of developing brains with the power to reason – not only in the history of the Earth, but, as far we know, in the entire universe. Gazing up at the stars, we find no evidence of other civilizations out there. Why is this?
The widely assumed answer is that it must be highly improbable for intelligence of our kind to evolve. It must require such a rare confluence of circumstances for this to happen that it essentially never does, with ourselves being the great exception. This makes us quite extraordinary.
The atomic-dino hypothesis offers a gloomier possibility. It suggests that our intelligence is actually not that unique, and that clever species like ourselves may, in fact, have evolved before, both on our own planet and elsewhere. The problem, however, is that technological civilizations, when they do emerge, are inherently unstable. They tend to wipe themselves out in short order, leaving behind little evidence of their existence. This is why the stars are silent, because everyone out there who was like us has destroyed themselves.
Such an idea may make us uncomfortable. It’s certainly easier to believe that we’re one-of-a-kind, but the atomic-dino hypothesis whispers a contrary warning: our advanced technology doesn’t make us as special as we like to think. In fact, if we’re not careful, it may cause us to go the way of the dinosaurs.
What if our ancestors were aquatic apes?
Imagine our ancestors ten million years ago. They may have looked a bit like gibbons – covered in fur, hanging from branches by their arms, running around on all fours between trees. Somehow, those primitive creatures transformed into us. Some of us are still rather hairy, but otherwise we’re dramatically different from those earlier primates. How did this transformation happen?
According to anthropologists, the change occurred during the millions of years our ancestors spent wandering the African landscape, migrating through woodlands and across dusty savannahs, until finally, after many generations had passed, their bodies came to look like ours. But, for over half a century, the aquatic-ape theory has made the case for a radically different and far stranger version of our history. It argues that our ancestors didn’t remain entirely on land, but instead took to the water for over a million years, swimming among the waves like dolphins, before eventually resuming a terrestrial existence. It was this ocean interlude, the theory says, that transformed them from ape-like creatures into beings resembling ourselves.
The father of the aquatic-ape theory was British marine biologist Alister Hardy. The idea came to him in 1929, while he was reading in his study. He was making his way through Man’s Place Among the Mammals by the naturalist Frederic Wood Jones when he came across a passage discussing the mystery of why humans have such a thick layer of fat beneath their skin. This made Hardy think of the various marine creatures he had observed on a recent trip to Antarctica. Many of them possessed a thick layer of blubber, and the parallel between this and human fat intrigued him. It was then that he had his flash of inspiration. A vision popped into his head of our ancestors living as aquatic apes. Or, more precisely, as semiaquatic apes. He pictured them dwelling along the African coast and diving into the water after fish, in the manner of penguins or seals, with the water streaming over their thin covering of fur.
Hardy kept his aquatic speculation to himself for thirty long years, fearing his colleagues would consider the notion absurd. He only revealed it to the world in 1960, at a meeting of the British Sub-Aqua Club. And it turned out he was right. His colleagues did think his theory was absurd. Faced with this rejection, Hardy moved on to another project: the search for a biological basis for telepathy. He had a fondness for against-the-mainstream ideas.
The affair of the aquatic ape might have ended there, barely having caused a ripple in academia, but, a decade later, out of the blue, it found an unlikely new champion: a fifty-two-year-old Welsh scriptwriter named Elaine Morgan. She had no scientific training at all, but she loved reading about science, particularly human evolution, and when she came across a reference to Hardy’s theory she said it was ‘as if the whole evolutionary landscape had been transformed by a blinding flash of light.’
Morgan became an instant convert and hard-core believer. She was so impressed that, despite her lack of a scientific background, she decided to launch a one-woman campaign to promote the aquatic ape. Her first book on the subject, The Descent of Woman, became an international bestseller and was eventually translated into twenty-five languages.
Morgan consequently became the mother of the aquatic ape, and it’s really to her that the theory owes its cultural prominence because she never gave up campaigning for it. She almost single-handedly raised it from obscurity, attracting to it a larger following than almost any other unorthodox theory in modern science enjoys.
The question at the heart of the aquatic-ape theory is this: why are we so unique as a species, in terms of our physical appearance? Just think about it for a moment. We really do look somewhat odd. Even among our primate relatives, like gorillas and chimpanzees, we stand out like a sore thumb.
Take the fact that we walk upright, on two legs. That alone marks us out as strange. How many other creatures are bipedal? Kangaroos perhaps, though they hop rather than walk. And birds – but again, they don’t walk, they fly. Why did it make evolutionary sense for almost all other terrestrial species to keep going around on all fours, but not us?
Then there’s our lack of fur. Having a covering of fur is eminently practical. It protects against the sun during the day and keeps you warm at night. Why did early humans lose theirs, while the vast majority of other land mammals kept a nice thick coat?
Throughout most of the twentieth century, from the 1920s to the 1990s, the standard anthropological answer to the puzzle of our appearance was that living on the open savannah was responsible. The idea was that, after our ancestors left the jungle, they moved on to the open plains of Africa, where they started walking upright because this allowed them to see over the tall grasses to spot predators. Upright, they could also hold and throw weapons. They lost their fur in order to stay cool while running around in the hot sun.
In the 1990s, this explanation had to be revised. Researchers were able to use fossilized pollen to reconstruct how the African landscape had changed over time, and they discovered that savannahs weren’t actually very common in Africa until two million years ago, by which time our ancestors were already hairless and walking
upright. The proto-humans, instead, would have inhabited a landscape filled with scattered woodlands and lakes, and it’s less obvious why bipedalism evolved in this environment. Researchers have speculated that standing upright may have allowed our ancestors to grab food from overhead branches. Or maybe it began as a way to walk along branches, like orangutans do. The loss of body hair still seems to have been a way of regulating internal temperature, though perhaps it also made early humans less susceptible to lice and other skin parasites.
Despite these revised explanations, the larger and accepted anthropological point of view has remained consistently the same, which is that the African landscape moulded our bodies into their current form.
Aquatic-ape advocates reject these explanations as nonsensical. That’s the crux of the dispute between them and mainstream science. They don’t believe these answers adequately account for our uniqueness. After all, they ask, whether our ancestors lived on the savannah or in woodlands, if it made so much sense to stand upright, why didn’t any other creatures make the same evolutionary choice? There were plenty of other animals living in the same landscape, including other primates. Why did only our ancestors discover the benefits of walking on two legs? And, if losing our fur helped so much with heat regulation, or controlling parasites, why did the vast majority of other land animals keep theirs?
The aquatic-ape theory concludes, to the contrary, that our singular appearance can only be explained if our ancestors weren’t exposed to the same landscape as all the other land mammals of Africa. Instead, they must have taken an evolutionary detour through an entirely different environment – the water. This then caused the development not only of our hairlessness and bipedalism but of a whole slew of other quirky anatomical attributes.
It was around five to seven million years ago, the theory contends, when a population of apes left their home in the jungles of Africa, journeyed to the coast and marched into the ocean. These apes became the founders of the human lineage.
It’s not entirely clear why they would have chosen to adopt an aquatic lifestyle. Perhaps it was because the water offered protection from predators such as big cats. Or they may not have made the move voluntarily. Climate change and flooding could have trapped some apes on a large island, forcing them to turn to marine resources for survival. Whatever the reason, the theory imagines that the apes continued a coastal existence for one or two million years, spending much of their time foraging in shallow water for shrimp and crabs, diving into deeper water for fish and sleeping at night on land. In this way, they gradually adapted to an aquatic environment before eventually returning fully to the land. Like the initial move into the water, the reason for this return isn’t totally clear. In the case of the island scenario, climate change may have reconnected their habitat to the mainland, prompting them to migrate along the coast and into the African interior.
This aquatic episode, according to the theory, permanently changed the bodies of the proto-humans in many ways. At the top of the list, as already noted, was our upright posture. There’s no environment on land that would have forced our ancestors to stand primarily on two legs. Other primate species, such as chimpanzees and baboons, walk on branches and grab fruit from overhead, and yet they continue to go around primarily on all fours.
If a group of apes had ventured into the water, however, they would have instinctively stood upright to keep their chests and heads dry. Modern-day chimps and gorillas do exactly this when wading across streams. As the ocean-going apes waded further out, the buoyancy of the water would have made it natural for them to rest their feet on the bottom while their heads bobbed above the waves.
Then there’s our lack of body hair. In the water, this would have helped to reduce resistance as we glided through the water. Hairlessness is an adaptation seen in many marine mammals, such as dolphins and seals. Though, it would have made sense to keep some hair on top of our heads to prevent our scalps from getting burned as they poked out above the water.
Bipedalism and hairlessness, however, are just the tip of the iceberg. Aquatic-ape advocates have a long list of other ways that the marine environment altered our anatomical features.
Beneath our furless skin, for example, lies a relatively thick layer of subcutaneous fat – far more than most other mammals have. This is the feature that inspired Hardy to dream up the aquatic-ape theory in the first place. It doesn’t seem to serve any obvious purpose on land, but in water it might have kept us warm and buoyant, much like the blubber found in whales, seals and penguins.
The protruding shape of our noses, which is so different from other primates, conveniently deflects water over and away from our nostrils when we dive in. We have a poor sense of smell compared to other land species, perhaps because there was no need to be able to smell while swimming. We also have voluntary control of our breath. That is, we can consciously regulate how much air we breathe in and how long we hold it in our lungs, which is why we can dive underwater for extended periods. Other land mammals can’t do this as well as we can, and it’s this ability to control our breath that allows us to speak. Our bodies even possess an instinctive diving response. When we jump into cold water, our heart rate and other metabolic processes automatically slow down, reducing our body’s consumption of oxygen. It’s an odd ability for a land mammal to have, but it would be entirely sensible for an ocean-going creature.
The list goes on and on, but the overall argument should be clear. The evolutionary choices made by our ancestors seem puzzling if they never left the land, because so often they changed in ways completely unlike the creatures around them. Aquatic-ape fans insist this must mean that our ancestors lived for a significant amount of time in the water.
For a long time, anthropologists tried to ignore the aquatic-ape theory – or the soggy-ape theory, as they sometimes like to call it. To them, its claims seemed to be so self-evidently absurd that they didn’t require refutation. They assumed the public would recognize the silliness of the whole argument. As the years passed, however, it became clear that the general population wasn’t having this reaction. In fact, a lot of people seemed to think the theory made pretty good sense. Increasingly vexed by the persistence of the soggy apes, anthropologists gradually swung into debunking mode.
Nowadays, if you dare broach the subject with an anthropologist, expect to get an earful in response, peppered with terms such as ‘pseudoscience’, ‘claptrap’ and ‘rubbish’. Press further and you’ll also get a long list of the reasons why they believe the theory to be wrong.
Topping this list is their conviction that the theory clumsily interjects an unnecessary extra step into the story of human evolution. We know present-day humans are terrestrial, as were our jungle ancestors. It’s simplest, therefore, to assume that our species has always lived on land, so we only need to account for the evolution of each feature once. If we speculate that our ancestors went through an aquatic phase on their way to becoming human, we have to explain how features first evolved in a marine habitat, and then why they were retained following the return to land. In the technical jargon of science, this extra explanatory step is non-parsimonious.
They also strongly disagree that any of our features seem designed for aquatic living, insisting that all of these apparent ‘marine adaptations’ dissolve upon closer examination. Take hairlessness. Losing our hair wouldn’t actually have given us any appreciable swimming advantage. There are, as we know, many semiaquatic mammals that are furry, such as otters.
Also, if our ancestors really had lived in a marine habitat, there are adaptations our species should have developed, but we never did. One random, but illustrative, example is internal testicles. All aquatic mammals keep theirs inside their body, because having these bits dangling in chilly water isn’t good for reproductive fitness. Best to keep them inside the body, where it’s warm. Our species’ external testicles strongly suggest we’ve always been terrestrial.
Anthropologists also complain that much of the supposed evidence
for the theory focuses on the evolution of soft body tissues, such as skin, hair and fat. The problem here is that these tissues aren’t preserved in the fossil record, which makes it difficult to know exactly when in our history such features developed or under what conditions. Because of this ambiguity, it’s easy to spin ‘just-so’ stories about the origin of these features, which is why anthropologists prefer to focus on the ‘hard’ evidence of fossils, which don’t give any indication of an aquatic phase in our evolution.
Perhaps anthropologists anticipated that, once they had explained why the aquatic-ape theory was wrong, everyone would wise up and lose interest in it. This hasn’t happened. Today, it’s as popular as ever. Some prominent intellectuals have even expressed support for it, including the philosopher Daniel Dennett, the zoologist Lyall Watson and the naturalist Sir David Attenborough, who’s hosted several aquatic-ape-boosting documentaries for the BBC.
What might be going on? Why does the theory endure?
Anthropologists lay a lot of the blame at the feet of Elaine Morgan, whom they’ve often accused of being like the charismatic leader of a pseudoscientific cult. If this is correct, Morgan’s death in 2013 should mean that support for the theory will now slowly start fading. Only time will tell.
Although anthropologists don’t like to admit this, the downfall of the savannah theory of human evolution in the 1990s did put a little bit of intellectual wind into the sails of the aquatic-ape model. It led several well-respected theorists, including the evolutionary biologist Carsten Niemitz and the anthropologist Phillip Tobias, to suggest that it might be worth considering a middle ground between the dry and wet theories of our evolution. They were quite willing to jettison most of the aquatic-ape model, but they urged their colleagues to have a second look at wading as a cause of bipedalism, arguing that it was as plausible as any other explanation for why we walk upright. They didn’t believe that our ancestors’ exposure to water would necessarily have occurred along the coast. Early humans could have lived along riverbanks, at the edge of lakes, or in woodlands subject to seasonal flooding. But wherever it might have been, wading could have given them an adaptive advantage.