What are the most successful organisms on the planet? Some people might think of apex predators like lions and great white sharks. For others, insects or bacteria might come to mind. But few would mention a family of plants that we see around us every day: grasses.
Grasses meet at least two criteria for spectacular success. The first is abundance. Grasses cover the North American prairies, the African savannahs and the Eurasian steppes, which span 5,000 miles from the Caucasus to the Pacific Ocean. A second criterion is the number and diversity of species. Since the time grasses originated, they have evolved into more than 10,000 species with an astonishing variety of forms, from centimetre-high tufts of hair grass adapted to the freezing cold of Antarctica to the towering grasses of northern India that can hide entire elephant herds, and to Asian bamboo forests, with “trees” that grow up to 30 metres tall.
But grasses weren’t always so spectacularly successful. For tens of millions of years – most of their evolutionary history in fact – grasses barely eked out a living. Their origin dates back to the age of dinosaurs, more than 65m years ago. But for many millions of years, the fossil record suggests, they were not abundant. In fact, it wasn’t until less than 25m years ago that they became the dominant species that we recognise today.
Why did grasses have to wait 40m years for their proverbial spot in the sun? This mystery deepens once you know that, early on, evolution endowed grasses with multiple survival-enhancing innovations. Among them are chemical defences like lignin and silicon dioxide that grind down the teeth of grazing animals. These features also protect grasses against drought, as do sophisticated metabolic innovations that help them conserve water.
With these and other innovations, you’d think that grasses would have quickly become dominant. But their delayed success holds a profound truth about new life forms. Success depends on much more than some intrinsic characteristic of a new life form, like an enhancement or a novel ability bestowed by an innovation. It depends on the world into which this life form is born.
Grasses are among myriad new life forms whose success – measured in abundance or diversity of species – was delayed for millions of years. The first ants appeared on the scene 140m years ago, but ants did not begin to branch into today’s 11,000 or more species until 40m years later. Mammals with various lifestyles – ground-dwelling, tree-climbing, flying or swimming – originated more than 100m years before they became successful 65m years ago. And one family of saltwater clams had to wait for an astonishing 350m years before it hit the big time, diversifying into 500 species.
These and many other new life forms remained dormant before succeeding explosively. They are the sleeping beauties of biological evolution. They cast doubt on many widely assumed beliefs about success and failure. And these doubts apply not just to the innovations of nature, but also to those of human culture.
For life to develop, it had to overcome challenges through innovation – such as how to extract energy from minerals, from organic molecules and from sunlight, or how to escape predators and stalk prey. Each of these kinds of challenges can be met in many ways, each emerging as a creative product of biological evolution, each embodied in a species with a unique lifestyle, millions of them and counting, as evolution marches on.
Innovation did not stop with biological evolution. Species with sophisticated nervous systems including chimpanzees, dolphins and crows have discovered simple technologies – tools they use to hunt or gather food. In the 12,000 years since the agricultural revolution, human culture has come up with revolutionary innovations such as mathematics and writing, as well as countless smaller ones, from the wheel to wallpaper. Countless sleeping beauties are among them. They include breakthrough technologies like radar, initially ignored, and scientific discoveries like the genetic laws of inheritance, which were neglected for decades.
Granted, nature and culture do not create in exactly the same way. The ink and paper of Newton’s Principia is a different substrate of creativity than the cells, tissues and organs in a blue whale. A writer’s grit in wrestling with the 15th draft of a chapter is a different motor of creation than random mutations of DNA. A patent’s commercial value is a different measure of success than how often the bacterium Escherichia coli divides every day.
But beyond these differences lie deep similarities. One of them is that a great number of innovations arrive before their time. Creative products without apparent merit, value or utility, but with the power to transform life given enough time, are everywhere in nature and culture. The sleeping beauties of nature can help us understand why creating may be easy, but creating successfully is beyond hard. It is outside the creator’s control.
The caterpillars of monarch butterflies are addicted to dangerous food. They devour the leaves of milkweeds, perennial herbs that grow a few feet tall, with tiny star-shaped flowers that form eye-catching clusters. Milkweeds may be beautiful, but they are not innocuous. When the mouthparts of a caterpillar slice into a milkweed leaf, pressurised channels inside the injured leaf release a substance that is milky white, hence the name milkweed. The caterpillars know that this white stuff means trouble, because they try to cut these channels and let the milk drain before they devour the leaf.
The scientific name of this milk is latex, a complex and sticky mixture of chemicals whose purpose is similar to that of sticky resins, like the yellow excretions of pine trees. Latex and resins are lethal defensive weapons against hungry animals. When insects bite a chunk out of a latex- or resin-producing plant, the sticky material can immobilise their mouthparts and glue them together. It can even entrap them whole. More than 30% of monarch butterfly caterpillars that hatch on the leaves of milkweed get mired in the plant’s latex, become glued to the leaf, and die. And such entrapment is only one line of defence embodied in latex and resins. Both secretions can also contain toxic chemicals, such as cardiac glycosides.
These chemical weapons are also examples of evolutionary innovations, so-called because they occur during the evolution of a species and help the species survive. And these specific innovations were not made by the milkweeds alone. Evolution discovered them not once, twice or a few times, but at least 40 different times in completely different species. What is more, many of the species that discovered them also independently evolved a distribution network for these toxic excretions, an elaborate system of channels that deliver the sticky stuff wherever a plant is attacked .
Latex, resins and their transportation networks are so important that biologists have elevated their status beyond that of mere innovations. We call them key innovations. That’s because they do more than just improve the survival of one plant species. They have more profound and long-term consequences for evolution.
Latex-producing plants suffer less insect damage, can grow faster, and spend more energy on reproducing by building flowers and producing seeds. These benefits allow such plants to spread further and colonise new habitats. In these habitats they eventually form new species. In the jargon of biology, such key innovations promote adaptive radiation, the sprouting of new branches on the tree of life. One species multiplies into many, each of them with its own lifestyle that is best suited to its own habitat.
The evolutionary potency of these chemical weapons is revealed by a study on 16 plant families. Each family not only produces latex and resins, it has a closely related family that lacks this ability. The study showed that 13 of the 16 latex-producing families had evolved more species – not just a few more, but up to 100 times more – than the related families without this ability.
Latex is an important innovation, but it is itself the product of an arms race that began with another innovation, an older one, discovered by insects. This innovation was phytophagy, the ability to use plants as food.
Hundreds of million years ago, primitive insects preyed only on other animals or lived on detritus, scavenging the carcasses of dead organisms. Switching from this diet to plants can’t have been easy. One obstacle to the vegetarian lifestyle are plants’ chemical defences, which are crucial for their survival, since plants can neither run nor hide. Another obstacle is that plant tissues and sap are poor in nutrients such as nitrogen and essential amino acids – much poorer than animal prey or detritus. What is more, detritus-feeders can hide in the ground, whereas plant-feeders take their meals out in the open. Their way of life exposes them not just to desiccation, but worse, to predators lured by their small, often poorly armoured and deliciously soft bodies.
Despite these obstacles, phytophagy was also discovered more than once, and not just two or three times, but at least 50 different times, by different species. And it became very successful, as biologist Charles Mitter from the University of Maryland and his collaborators proved. These researchers showed that branches of plant-eating insects on the tree of life tend to produce more species, and sometimes many more, than their non-plant-eating counterparts. For example, within an insect family also known as Chloropidae, the plant-eating branch has more than 1,350 species, whereas the other has only 80 species. Even though only a few insect orders – large groups of species like beetles, cockroaches and dragonflies – discovered phytophagy, it became so successful that today, half of the world’s 900,000 insect species feed on plants. Phytophagy is another one of evolution’s key innovations.
One view of adaptive radiation is that a key innovation enables radiation, and that its absence prevents radiation. Only with a key innovation can a species exploit existing opportunities, such as a warmer climate or a new source of food. In this view, any one adaptive radiation has to wait, possibly for a long time, until the right innovation arises. And the need to wait holds evolution back. But innovations like latex production and phytophagy cast doubt on this view, because they have originated so many times.
Perhaps evolutionary innovation is easier than we think? Perhaps evolution does not have to wait for innovations? Perhaps its creative engine is more powerful than we give it credit for? The astonishing speed with which evolution can respond to new opportunities suggests this possibility.
The examples of latex production and phytophagy leave us with two possibilities. The first is that evolution is no more than a nimble innovator. It reacts just in time to a changing environment and tracks many such changes closely over time. If so, it innovates only in the wake of evolutionary opportunities, like the rise of a mountain range or the rifting of a continent. The second possibility is more tantalising. What if many innovations arise before their time, but flourish only when conditions are right?
If innovations come easily to evolution, they come just as easily to culture, and multiple discoveries support this claim. One ancient example is agriculture, which has at least 11 independent origins, including in the Middle East, China, Africa and New Guinea, with crop plants as different as wheat, rice and corn. The multiple discoveries of latex in biological evolution also have a parallel in human history: the commercially useful form of latex, ie natural rubber.
The milky white latex bleeding from wounded rubber trees is chemically unstable. To create useful, stable natural rubber from it requires a process called vulcanisation. When the inventor Charles Goodyear accidentally discovered this process in 1839, he triggered a commercial revolution of natural rubber products. They became so crucial to the Industrial Revolution that, a century later, the president of the Goodyear Tire & Rubber Company could call rubber the “flexing muscles and sinews” of industrial society. By the time of the second world war, a tank needed 3,600kg of rubber, and a battleship hundreds of tons. Rubber had become a vital and hugely valuable commodity.
It seems that the explosive success of rubber had to wait only for a singular discovery. In fact, pre-Columbian Amerindians had beaten Charles Goodyear by almost 3,500 years. They had discovered how to heat raw latex with the juice of a morning glory vine to achieve vulcanisation. The rubber products they produced included figurines, rubber bands and rubber balls for ritualised ballgames that enacted their creation myths. But because their innovation came too early, its impact on humanity was negligible.
Examples of multiple discoveries become ever more plentiful as we approach the present, perhaps because our historical records become better, perhaps because the pace of innovation is accelerating. The pendulum clock was invented at least three different times, the thermometer seven times, the telegraph four times and radar six times.
Many individual inventors would object to the general point here that innovations come easy. After all, innovating seems difficult, even for some of humanity’s most prolific inventors. Thomas Edison had to try 6,000 different materials before stumbling upon bamboo as a stable filament for incandescent lightbulbs. But what feels arduous for individual innovators may look very different from a higher vantage point, like that of a historian studying an entire historical epoch. From that vantage point, most inventions and discoveries are not hard-won singular events of history, but almost inevitable products of their time.
In about a third of inventions, more than 10 years elapsed between two independent discoveries. That’s a hint that early discoveries are often ignored or forgotten. The obvious question is why. Among such examples is the cure for scurvy, a deadly disease that an 18th-century observer called “the plague of the sea”, because it killed countless sailors who spent month after month on the open ocean. Its symptoms start innocuously enough with a lack of energy and gum pain. They crescendo into muscle pains and loosening teeth. And they climax in ailments – festering wounds, bleeding, convulsions – that will reliably end in death.
Scurvy’s death toll became most evident in the age of detailed naval records, and most dramatic when colonial powers began to explore the oceans in search of new territories, further and further from home, their ships spending more and more time away from land. When circumnavigating the world in 1520, the explorer Magellan lost 208 of 230 men. Two centuries later, in 1740, on an expedition to harass the Spanish in the Pacific, the British naval commander George Anson lost 1,300 of almost 2,000 men. In both expeditions, scurvy was to blame for most deaths.
A potent cure for scurvy – citrus fruit and fresh vegetables – was not just discovered and forgotten, but rediscovered and reforgotten more than once. Vasco da Gama discovered it in 1497 – together with a sea route to India – in the form of oranges, but his knowledge did not spread. In 1614 a British naval handbook entitled The Surgeon’s Mate endorsed it, too, but its words must have fallen on deaf ears, because even as late as the 18th century, the British navy lost more sailors to disease than to battles, and the major culprit was still scurvy.
A third discovery came in the form of a decisive medical experiment, a milestone in the history of medicine. Sadly, this one made no difference either. The experiment was the first controlled clinical trial, a trial of potential remedies for scurvy performed by naval surgeon James Lind in 1747. At that time, Lind served on a British warship where 80 of 350 men were struck down by scurvy. He isolated 12 sailors who were dying from scurvy, and fed each of them a basic diet supplemented with one of six different antiscorbutics – potential remedies for scurvy. Two sailors received oranges and lemons, another two vinegar, another two cider, a fourth pair drank seawater and so on. After two weeks, the first pair had almost completely recovered. Among the other pairs, only those who had received cider had improved a bit. A clearcut result: citrus fruit can cure scurvy.
Lind summarised his research in his 1753 Treatise of the Scurvy. He was well connected to the Admiralty, which could influence the fleet’s health policy, but even so the Admiralty ignored the connection between citrus fruit and scurvy for another half a century. Some historians claim that Lind was undermined by competitors who favoured other antiscorbutics. Others saw Lind as too far ahead of his time, an intellectual revolutionary held back by countless reactionaries who resented his genius. The truth is more complicated.
Long ocean voyages deprived sailors of more than just fresh food. Quarters were damp and dirty, the air stuffy, and the drinking water stale. So when sailors reached land and their health improved, who was to say whether it was the good food, the fresh air or the pure water? The complexity of the problem also played to a deeply held belief of 18th-century medicine. This belief was opposed to today’s view that many diseases have specific causes, be it a viral infection, a genetic mutation or a vitamin deficiency. At the time, doctors believed that any one disease can have multiple causes; you might get scurvy from unclean water, damp air or dirty quarters, and the actual cause would depend on your constitution. And if diseases have multiple causes, so the thinking went, they must also have multiple cures. For this reason, the medical establishment frowned on what was called a “specific” – a remedy for a single disease that worked for all people. If a physician claimed to have found one, accusations of quackery would often follow.
Eventually, common sense would win against medical prejudice, but it would take almost another half century. An important validation of citrus fruit came from a 1793 scurvy outbreak in the British fleet. The outbreak was quashed when lemon juice brought in from port helped to heal suffering sailors. By 1795 it was official policy to supply all ships in the fleet with lemon juice, and in 1867 the practice was also forced on civilian ships.
Lemon juice could cure scurvy, but for several more decades nobody knew why. The final answer would not arrive until 1927, when the Hungarian biochemist Albert Szent-Györgyi isolated a molecule he called ascorbic acid, after others had shown that it was the ultimate specific antiscorbutic. Today we know it as vitamin C.
The discovery of a cure for scurvy was premature: its success had to await other developments. In other words, the success of scientific discoveries, like that of technological innovations, can require multiple building blocks.
Some of these building blocks need not even be scientific discoveries. They may come from outside science. When Alexander Fleming discovered penicillin in 1928, it would remain a laboratory curiosity for more than 10 years. The reason: discovering an antibiotic-producing mould is one thing, and turning that discovery into a useful drug is another. Nobody showed much interest at the time, so Fleming himself gave up penicillin research in 1929. When interest in penicillin eventually arose, one of the reasons was entirely non-scientific: the second world war was raging and thousands of soldiers were dying from infected wounds. But even with that motivation, the isolation, clinical testing and mass-production of penicillin required a multi-year effort and interdisciplinary teams from the UK and US. Only in March 1942 would the first US patient be treated with penicillin.
Just like the innovations of biological evolution, many human inventions and discoveries lie dormant. There are many reasons for their dormancy. Some of them may involve little more than dumb misfortune. Others include entrenched prejudice, inertia to change and marketing power. Still others are scientific discoveries or technological developments that lie in the future. Because every one of them is unique, they seem to have little in common. But deep down, they do share something, and that something is crucial: all of them lie outside the creator’s control. And this commonality, which runs like a red thread all the way back to the origin of life, may also hold a few lessons for human creators today.
This is an edited extract from Sleeping Beauties: the Mystery of Dormant Innovations in Nature and Culture by Andreas Wagner, published by Oneworld and available at guardianbookshop.com
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