by Michio Kaku
So the combination of the first and second criteria gives the animal the ability to use hand-eye coordination to hunt for prey and also to manipulate tools. But the third criterion ties it all together.
3. Language
Among most species, any lesson an individual might learn dies with that animal.
In order to hand down and accumulate essential information from generation to generation, some form of language is crucial. The more abstract the language, the more information can be conveyed between generations.
Being a hunter helps encourage the evolution of language, because pack predators have to communicate and coordinate with one another. Language is primarily useful for pack animals. While a single hunter may be crushed by a mastodon, a group of hunters can ambush, surround, trap, snare, and bring down a mastodon. Furthermore, language is necessarily a social phenomenon that accelerates the development of cooperation among individuals. This was an essential ingredient in the rise of human civilization.
I had a graphic example of the social aspects of language when I swam in a pool full of playful dolphins for a TV program with the Discovery Channel. Inserted in the pool were sonic sensors that recorded the chirps and whistles that they used to communicate with one another. Although they don’t have a written language, they have an audible one, which can be recorded and analyzed.
Then, using a computer, one can look for patterns that indicate intelligence. For example, if one randomly analyzes the English language, one finds that the letter e is the most common letter in the alphabet. One can then compile a list of letters and analyze how frequently each one is used, providing a distinctive “fingerprint” for that language or particular person. (This can be used to trace the authorship of historical manuscripts—to show, for example, that Shakespeare really did write his plays.)
Similarly, one can record the communications between the dolphins and find that the repetition of their chirps and whistles obeys a mathematical formula.
One can then analyze the language of a number of other species, such as dogs and cats, and find a similar telltale sign of intelligence.
However, as we start to analyze the sounds of insects, we find less and less evidence of intelligence. The point is that animals do have primitive languages, and computers can mathematically calculate their complexity.
EVOLUTION OF INTELLIGENCE ON EARTH
So if at least three attributes are necessary for the development of intelligent life, then we can ask, How many animals on the Earth have all three of them? We find that many predators with stereoscopic vision have claws, paws, fangs, or tentacles but lack the ability to grasp tools. Similarly, none have a sophisticated language that allows them to hunt, share information with others, and hand information down to the next generation.
We can also compare human evolution and intelligence with those of the dinosaurs. Although our understanding of dinosaur intelligence is extremely limited, it is believed that they dominated the Earth for about two hundred million years, yet none of them became intelligent or developed a dinosaur civilization, which took humans only about two hundred thousand years.
But if we analyze the dinosaur kingdom carefully, we see signs that intelligence might have flourished. For example, the velociraptors, immortalized in Jurassic Park, probably could have become intelligent with time. They had the stereo eyes of a hunter. They hunted in packs, which meant they probably had some communication system between them to coordinate the hunt. And they had claws for grasping prey, which might have evolved into opposable thumbs. (By contrast, the limbs of the Tyrannosaurus rex were tiny, probably used only to grab the flesh after the hunt was over and unlikely to be of much use in grasping tools. The T. rex was essentially a walking mouth.)
ALIENS FROM STAR MAKER
Given this framework, we can analyze the aliens found in Olaf Stapledon’s Star Maker. The hero of that story takes an imaginary journey across the universe, encountering scores of fascinating civilizations. We see the panorama of possible intelligence spread across the canvas of the whole Milky Way galaxy.
One alien species evolved on a planet with a large gravitational field. Hence, instead of four legs, they required six legs to walk. Eventually, the front two legs evolved into hands, freeing them up to use tools. Over time, this animal evolved into something resembling a centaur.
He meets aliens that are insect-like. Although each insect is not intelligent, the combination of billions of them creates a collective intelligence. A birdlike race flies in gigantic swarms, like a cloud, and also develops a hive mind. He meets intelligent plantlike creatures that, during the day, are inert like plants but at night can move like animals. He even meets intelligent life-forms that are totally outside our experience, such as intelligent stars.
Many of these alien creatures live in the oceans. One of the most successful of these aquatic species is a symbiosis of two different life-forms, resembling a fish and a crab. With the crab riding behind the fish’s head, they can travel rapidly like a fish and the crab can manipulate tools using its claws. This combination gives them a tremendous advantage as they become the dominant species on their planet. Eventually, the crab-like creatures venture onto the land, where they invent machines, electrical appliances, rocket ships, and a utopian society based on prosperity, science, and progress.
These symbiotic creatures develop starships and encounter less advanced civilizations. Stapledon writes, “Great care was taken by the Symbiotic race to keep its existence hidden from the primitives, lest they should lose their independence.”
In other words, although the fish and the crab separately could not evolve into a higher creature, the combination of the two could.
Given that the vast majority of alien civilizations, if they exist, may live underwater on ice-covered moons (like Europa or Enceladus) or on the moons of rogue planets, the question is, Can an aquatic species become truly intelligent?
If we analyze our own oceans, we see several problems. Fins are an extremely efficient way of traveling in the oceans, while feet (and hands) are not. One can travel and maneuver quite quickly with fins, while moving with feet on the ocean floor is clumsy and awkward. Not surprisingly, in the oceans we see few animals that have evolved appendages that can be used to grasp tools. So creatures with fins are unlikely to become intelligent (unless the fins somehow evolve so they can grasp objects, or else these fins were actually arms and legs of land animals that returned to the oceans, like dolphins and whales).
However, the octopus is a very successful animal. Having survived for at least three hundred million years, it is perhaps the most intelligent of all invertebrates. When we analyze the octopus with regard to our criteria, we find that it matches two out of three of them.
First, being a predator, it has the eyes of a hunter. (However, its two eyes do not focus stereoscopically well toward the front.)
Second, its eight tentacles give it an extraordinary ability to manipulate objects in its environment. These tentacles have remarkable dexterity.
But it has no language to speak of. Being a solitary hunter, there is no need to communicate with others. There is also no interaction between generations as far as we can tell.
Thus, the octopus displays a certain intelligence. They are notorious for being able to escape from aquariums, taking full advantage of their soft bodies to squeeze through tiny cracks. They also can navigate through mazes, showing they possess some form of memory, and they have been known to manipulate tools. One octopus was able to grab coconut shells and create a shelter for itself.
So if the octopus has some limited intelligence and versatile tentacles, then why didn’t it become intelligent? Ironically, it’s probably a testament to its success. Hiding under a rock and grabbing prey with its tentacles is a very successful strategy, so octopi probably had no need to develop intelligence. In other words, there was no evolutionary pressure placed on them to evolve greater intelligence.
However, on a distant planet under different con
ditions, one can imagine that an octopus-like creature could develop a language of chirps and whistles so it could hunt in packs. Perhaps the beak of the octopus can evolve to produce the rudiments of language. One could even imagine that at some point in the distant future evolutionary pressures on Earth could force the octopus to develop intelligence.
So an intelligent race of octopods is certainly a possibility.
Another intelligent creature envisioned by Stapledon was a bird. Scientists have noticed that birds, like the octopods, have significant intelligence. Unlike the octopus, however, they have a very sophisticated way of communicating with one another, through chirps and also through songs and melodies. By recording the songs of certain birds, scientists have noticed that the more sophisticated and melodic the song, the greater the attraction from the opposite sex. In other words, the complexity of a male bird’s song allows the female bird to judge its health, its strength, and its suitability as a mate. So there is an evolutionary pressure on them to develop complex melodies and a certain intelligence. Although some birds have the stereo eyes of a hunter (such as hawks and owls) and a form of language, they lack the ability to manipulate the environment.
Millions of years ago, some of the animals that walked on four legs evolved into birds. By analyzing the bones of birds, we see precisely how the bones of the legs slowly evolved into the bones of the wing. There is a one-to-one match between the two sets of bones. But to truly manipulate the environment, one would want animals whose hands are free to grasp tools. This means that intelligent birds will either have to evolve modified wings that have a dual purpose, allowing both flight and the manipulation of tools, or they need to start with at least six legs, four of which eventually become wings and hands.
So an intelligent species of birds is possible, if they could somehow develop the ability to manipulate tools.
These are just a few examples of how varied intelligent species might be. There are certainly many other possibilities one could contemplate.
HUMAN INTELLIGENCE
It is illustrative to ask, Why did we become intelligent? Many primates come close to satisfying all three criteria, so why did we develop these abilities, rather than chimpanzees, bonobos (our closest evolutionary relative), or gorillas?
When we measure Homo sapiens against other animals, we see that we are weak and clumsy by comparison. We might easily be the laughingstock of the animal kingdom. We can’t run very fast, we have no talons or claws, we cannot fly, we don’t have a keen sense of smell, we have no armor, we aren’t very strong, and our skin has no fur and is quite delicate. In every category, we see that there are animals that are vastly superior physically.
In fact, most animals we see around us are very successful and hence had no evolutionary pressure to change. Some animals haven’t changed for millions of years. Precisely because we are weak and clumsy, we were under enormous pressure to acquire skills the other primates lacked. To compensate for our deficiencies, we had to become intelligent.
One theory states that the climate in East Africa began to change several million years ago, causing the forests to recede and the grasslands to spread. Our ancestors were forest creatures, so many of them died off when the trees began to disappear.
Those who did survive were forced to move from the forests onto the savannah and grasslands. They had to wrench their backs and walk upright, allowing them to see above the grass. (We see evidence of this in our swayback, which puts enormous pressure on the small of our back. This is the reason why back problems are one of the most common health issues facing middle-aged people.)
Walking upright had another great advantage: it freed up our hands so we could manipulate tools.
When we encounter intelligent aliens in space, chances are good that they, too, will be clumsy and weak and will have compensated for these deficiencies by evolving intelligence. And they, like us, will evolve the ability to survive by a new technique: the ability to alter their environment at will.
EVOLVING ON DIFFERENT PLANETS
So then how might an intelligent creature develop a modern technological society?
As we’ve discussed, the most common form of life in the galaxy might be aquatic. We’ve already looked at whether sea creatures can develop the requisite physiology, but there is a cultural and technological component to our story as well, so let us see if an advanced civilization can rise from the bottom of the ocean.
For humans, after the discovery of agriculture, this process of developing energy and information went through three stages.
The first stage was the industrial revolution, when the energy of our hands was magnified many times by the power of coal and fossil fuels. Society exploded with power, converting a primitive agrarian culture into an industrial one.
The second stage was the electric age, when the power available to us was augmented by electric generators and new forms of communication arose, including radio, TV, and telecommunications. As a result, both energy and information flourished.
The third stage is the information revolution, when computer power came to dominate society.
We can now ask the simple question, Can an aquatic alien civilization also go through these three stages of development in energy and information?
Because Europa and Enceladus are so far from the sun, and since their oceans are perpetually under an ice cover, any intelligent creature on these distant moons will probably be blind, like the fish who live in dark caves beneath the surface of the Earth. Instead, they will probably develop some form of sonar, using sound waves as bats do in order to navigate the oceans.
But since the wavelength of light is so much smaller than the wavelength of sound, it means that they will not be able to see the fine details that we can with our eyes (just as sonograms used by doctors provide far less detail than endoscopy). This will slow down their march toward creating a modern civilization.
But more important, any aquatic species will have a problem with energy, since you cannot burn fossil fuels in water and it’s difficult to shield electrical power. Most industrial machinery would be useless without oxygen to create combustion and mechanical motion. Solar power would also be useless, since sunlight would not penetrate the perpetual ice cover.
Without internal combustion engines, fires, and solar power, it would seem that any alien aquatic species would lack the energy to develop into a modern society. There is one source of untapped energy that is available to them, however, and that is geothermal energy coming from heat vents on the bottom of the ocean. Like the volcanic vents on the bottom of our own oceans, similar vents on Europa and Enceladus may provide a convenient energy source for tools.
It might be possible to create an underwater steam engine as well. The temperature of the vents might be well beyond the boiling point of water. If the heat from these vents can be channeled, then creatures might be able to use it to create a steam engine, using a system of pipes that can draw boiling water from these vents and then channel it to move a piston. From this, they might be able to enter the machine age.
It might also be possible to use this heat to melt ores in order to create a metallurgy. If they can extract and mold metal, then they can create cities on the bottom of their oceans. In short, it may be possible to create an underwater industrial revolution.
An electric revolution seems improbable, since water would short-circuit most traditional electrical appliances. Without electricity, all the wonders of that age would be impossible, so their technology would be stunted.
But here also, there is a possible solution. If these creatures can find magnetized iron on the bottom of the oceans, then it’s possible to create an electrical generator, which then can be used to power machinery. By spinning these magnets (perhaps by jets of steam hitting a turbine blade), they could push electrons in a wire, creating an electrical current. (This is the same process used in bicycle lamps and hydroelectric dams.) The point is that intelligent underwater creatures might be able to create elect
ric generators using magnets even in the presence of water, and hence enter the electric age.
The information revolution, with computers, is also difficult but not impossible to master for an aquatic species. Just as water is the perfect medium to spawn life, silicon is also the likely basis for any chip-based computer technology. There could be silicon on the bottom of the ocean, which can be mined, purified, and etched to create chips via ultraviolet light, just as we do. (To create silicon chips, UV light is passed through a template that contains the blueprint for all the circuits on a chip. The UV light and a series of chemical reactions creates a pattern that is etched onto a silicon wafer, creating transistors on the chip. This process, which is the basis of transistor technology, can also be done underwater.)
So it would be possible for an aquatic creature to develop intelligence and to create a modern technological society.
NATURAL BARRIERS TO AN ALIEN TECHNOLOGY
Once a civilization begins the long, arduous process of becoming a modern society, it faces yet another problem. There may be a series of natural phenomena that get in the way.
For example, if intelligent creatures evolved on a place like Venus or Titan, they may be faced with a permanent cloud cover over their world, so they would never see the stars. Their concept of the universe would be limited to their planet.
This means that their civilization will never develop astronomy, and their religion would consist of tales that are confined to their planet. Since they will have no urge to explore beyond the clouds, their civilization will also be stunted, and it is highly unlikely they will develop a space program. Without a space program, they would never have telecommunication and weather satellites. (In Stapledon’s novel, some creatures living beneath the surface of the sea eventually came onto land, where they discovered astronomy. If they had stayed in the oceans, they would never have discovered the universe beyond their planet.)
