Chapter 6 Chapter 4 The Gene Machine

Survival machines originally existed as reservoirs of genes.Their role is passive and merely serves as a protective barrier for genes against chemical warfare and accidental molecular attacks by their adversaries.In ancient times, the organic molecules present in abundance in the primordial soup were the food they depended on.With the depletion of these organic foods, which have been bred for thousands of years under the powerful influence of sunlight, the once-free life of the survival machines is over.At this point, a large branch of them, now known as plants, began to use sunlight directly to build complex molecules from simple molecules, and to repeat the synthesis process that took place in the primordial soup at a much faster rate.Another branch, now known as animals, discovered how to use the fruits of the chemical labor of plants.Animals either eat plants or other animals.Over time, these two branches of survival machines developed increasingly subtle skills to enhance the efficacy of their way of life.At the same time, new ways of life emerge one after another, and small branches and small branches are gradually formed, each small branch is in a special aspect, such as in the sea, on land, in the sky, underground, on trees, or in other living bodies. , Obtain superhuman survival skills.This process of continual formation of small branches has at last produced the rich variety of flora and fauna which so impresses mankind today.

Both animals and plants have evolved into multicellular bodies, with each cell receiving a complete copy of the full set of genes.When this evolutionary process began, why it happened, and completed in several separate stages, we have no way of knowing.Some people use colony as a metaphor for the bodies of animals and plants, saying that they are colonies of cells.I would rather see the body as a group of genes, and the cells as the working units for the chemical industry of genes to operate. Although we may refer to bodies as groups of genes, each body does acquire its own unique personality in terms of its behaviour.An animal acts as an internally coordinated whole, a unit.I subjectively feel that I am a unit rather than a group.This is to be expected.The selection process favors those genes that cooperate with other genes.In order to compete for rare resources, to devour other survival machines and avoid being eaten by each other, survival machines are engaged in fierce and ruthless competition and struggle.For all this competition and struggle, it must be far more advantageous to have a centrally coordinated system within a shared body than to have anarchy.Today, the staggered co-evolutionary processes that occur between genes have advanced to the point where the communal nature exhibited by individual survival machines is virtually unrecognizable.In fact, many biologists do not recognize the existence of such clusters, and therefore disagree with me.

As far as the reliability (in journalistic terms) of the arguments presented in later chapters of this book is concerned, the disagreement is fortunately largely academic.It would be tiresome, and unnecessary, to refer repeatedly to genes when we were talking about the behavior of survival machines, just as it would be inconvenient to refer to quantum and elementary particle reflexes when we were talking about the performance of a car.In fact, it is generally convenient to refer to the individual as an agent who seeks to increase the genetic population in future generations.And I will use simple language.Unless otherwise stated, altruistic behavior and selfish behavior refer to the behavior of one animal individual towards another animal individual.

This chapter will deal with behavior, the kind of rapid motion widely exploited by the animal branch of survival machines.Animals have become active and aggressive gene delivery vehicles, gene machines.In the vocabulary of biologists, behavior has a fast quality.Plants move too, but very slowly.Climbing plants look like active animals in fast-motion movies, but most plant activity is really limited to irreversible growth.Animals, on the other hand, have developed various modes of activity that are hundreds of thousands of times faster than plants.Furthermore, the animal's movements are reversible and can be repeated countless times.

The mechanisms that animals develop to perform rapid movements are muscles.Muscle is the engine, which, like a steam engine or an internal combustion engine, uses its stored chemical fuel as energy to generate mechanical motion.The difference: Muscles generate direct mechanical force in the form of tension, rather than air pressure like a steam or internal combustion engine.But muscles are like engines in that they typically exert their power by means of ropes and hinged levers.In the human body, the levers are the bones, the cords are the tendons, and the hinges are the joints.Much is known about how muscles work molecularly, but I find it more interesting to ask how we control when and how fast muscles contract.

Have you ever observed a complex man-made machine?For example, knitting or sewing machines, textile machines, automatic bottling machines or hay balers.These machines utilize a variety of prime movers, such as electric motors or tractors.But how to control the time and speed of these machines in operation is a more complicated problem.Valves open and close sequentially, steel hay balers deftly tie knots and extend knives at just the right moment to cut the string.The timing of many man-made machines is accomplished by means of cams.The invention of the cam was indeed a brilliant achievement.It uses eccentric or profiled wheels to transform simple movements into complex, rhythmic ones.The principle of automatic playing musical instruments is similar to this.Other instruments, such as the steam organ, or the player piano, used paper scrolls or cards with holes punched in a pattern to produce the tones.In recent years, these simple mechanical timing devices have tended to be replaced by electronic timing devices.Digital computers are an example.They are large, versatile electronic devices that can be used to generate complex timed actions.The main components of modern electronic instruments such as computers are semiconductors, and the transistor we are familiar with is a form of semiconductor.

Survival machines seem to have bypassed cams and punch cards.It uses a timing device that has more in common with an electronic computer, although strictly speaking, the basic operation of the two is different.The basic unit of a biological computer is the nerve cell, or neuron.As far as its internal workings are concerned, it is completely different from a transistor.The code that neurons use to communicate with each other is indeed a bit like a computer's pulse code, but a neuron is a much more complex data-processing unit than a transistor.A neuron can communicate with other units through tens of thousands of wires, not just three.Neurons work slower than transistors, but when it comes to miniaturization, transistors are far inferior.Thus, miniaturization is a trend that has dominated the electronics industry for the past two decades.In this regard, the following fact is very telling: there are about ten billion neurons in our brains, and no more than a few hundred transistors can be packed into a single brain.

Plants don't need neurons because they don't have to move to live.But most animal taxa have neurons.In the evolution of animals, they may have discovered neurons early and inherited them for all groups; or they may have been rediscovered several times separately. Fundamentally, a neuron is nothing more than a type of cell.Like any other cell, it has a nucleus and chromosomes.Instead, its cell walls form elongated, thin, thread-like protrusions.Usually a neuron has a particularly long thread, which we call an axon.An axon is so narrow in width that it can only be seen under a microscope, but it can be several feet long.Some axons are even as long as a giraffe's neck.Axons are usually bundled together in multiple strands to form the multi-core wires we call nerves.These axons run from one part of the body to the other, carrying messages like telephone trunks.Other kinds of neurons have short axons that are only found in the dense nervous tissue we call ganglia.If they are very large neurons, they are also present in the brain.In terms of function, we can think of brains and computers as being similar in that both types of machines emit complex patterns of output signals after analyzing complex patterns of input signals and referring to stored data.

The main way in which the brain actually contributes to the survival machine is by controlling and coordinating the contraction of muscles.To do this, they need wires, called motor nerves, that lead to the individual muscles.But effective preservation of genes is only possible if there is a relationship between the timing of muscle contractions and the timing of external events.The muscles in the upper and lower jaw have to wait until there is something worth chewing in the mouth to contract.Likewise, it only makes sense for the leg muscles to contract in a running pattern when there is something worth running for or something that must be avoided.For this reason, natural selection has favored animals equipped with sensory organs that translate various forms of physical events occurring in the external world into neuronal impulse codes.The brain is connected to sensory organs such as the eyes, ears, and taste buds by wires called sensory nerves.How sensory systems work is especially puzzling, since their highly sophisticated skill at recognizing images far exceeds that of the best and most expensive man-made machines.If this is not the case, typists will become redundant, because their work can be completely done by machines that recognize speech or handwriting.Typists will not be out of a job for decades to come.

At some point in the past, the sensory organs may have been connected directly to the muscles in some way, and in fact, today's anemones are not completely out of this state, because such a connection is valid for their way of life.But in order to establish a more complex and indirect connection between the timing of various external events and the timing of muscle contractions, some form of brain is required as an intermediary.A remarkable advance in the course of evolution was the invention of memory.With this memory, the timing of muscle contractions is influenced by events not only in the immediate past but also in the distant past.Memory, or storage, is also an essential component of digital computers.Computer memories are more reliable than ours, but they have smaller capacities and are far inferior to ours in information retrieval skills.

The behavior of survival machines has one of the most prominent features, which is the obvious purpose.When I say this, I don't just mean that survival machines seem to be deliberate in helping animals survive genetically, even though they are.I am referring to the fact that the behavior of survival machines more closely resembles the purposeful behavior of humans.When we see animals searching for food, a mate, or a lost child, we can't help thinking that those animals are feeling some of the same feelings we ourselves experience when we are searching.These feelings may include a desire for an object, a mental image of the desired object, and a purpose in mind.Each of us knows from experience that at least one of the modern survival machines has evolved so that this purpose gradually acquires the quality we call consciousness.I am not well versed in philosophy, so I cannot delve into the implications of this fact.But this is fortunately irrelevant so far as we are concerned with the subject.For it is convenient for us to speak of machines operating as if motivated by some purpose, whether or not they are actually conscious.These machines are fundamentally very simple, and the principle of mindless tracking of target states is frequently used in engineering science.A typical example is the Watt steam governor. The basic principle involved is what we call negative feedback, and negative feedback can take many forms.Generally speaking, it works like this: the purposive machine works as if it had a conscious purpose, equipped with some measuring device which measures the difference between the existing state of things and the desired state.The way the machine is structured allows it to go faster as the gap increases.In this way, the reason why the machine can automatically reduce the gap is called negative feedback, because when the required state is realized, the machine can automatically stop running.A pair of balls mounted on a Watt governor are rotated by the impetus of a steam engine.The two balls are respectively installed on the tops of the two movably connected lever arms.As the rotational speed of the ball increases, the centrifugal force gradually counteracts the result of the gravitational force, making the lever arm more and more horizontal.As the lever arm is attached to the valve that supplies the machine with steam, the supply of steam is gradually reduced as the lever arm approaches horizontal.Therefore, if the machine is run too fast, the steam feed will be reduced, and the speed of the machine will be slowed down.Conversely, if the machine is running too slowly, the valve will automatically increase the steam feed, so that the speed of the machine will also increase.However, due to the relationship between overshoot or time lag, this type of destination machine often oscillates.To compensate for this deficiency, engineers always try to add some kind of device to reduce the amplitude of this oscillation. The state required by the Watt governor is a certain rotational speed.Obviously, the machine itself does not consciously require this speed.The so-called purpose of a machine is nothing but its tendency to return to that state.Modern purpose machines extend basic principles such as negative feedback to enable much more complex and lifelike actions.For example, the missile appears to be actively searching for a target and pursuing it once it is within range, while also taking into account the various twists and turns of a target's evasive pursuit, and sometimes even anticipating it or preempting it.These details are not discussed here.Simply put, they involve various negative feedback, feed-forward, and other principles familiar to engineers.As far as we know, these principles are now widely used in the movement of living bodies.We don't need to think of a missile as having anything close to consciousness, but to an ordinary person it's hard to believe that the missile's apparently deliberate, purposeful movements were not directed by a pilot. controlling. A common misconception is that if a machine such as a missile is designed and built by a conscious being, then it must be under the direct control of a conscious being.Another variation on this misconception: Computers can't really play chess, because they can only listen to the human operator.We must understand the source of this misunderstanding as it affects our understanding of what it means to say that genes control behavior.Computer chess is a very telling example, so I want to touch on it briefly. Computer chess today is not at the level of a grand master, but it is comparable to a good amateur player.It is more accurate to say that a computer program is as good as a good amateur chess player, because the program itself is never demanding on which specific computer is used to perform its skills.So, what is the task of the programmer?First, he certainly wasn't manipulating the computer 24/7 like a puppeteer.This is cheating.He programmed it, put it in the computer, and the computer operated on its own: no human intervention.In addition to letting the opponent press his move into the machine.Did the programmer anticipate all possible moves and thus compile a long list of clever moves for each situation?Of course not.Because in a chess game, there are as many possible moves as there are sands in the Ganges River, and even at the end of the world, it is impossible to compile a complete list.Also for the same reason, it is impossible for us to compile such a program for the computer, so that it can take all possible moves and all possible responses in the computer in advance, so as to find a strategy to defeat the enemy.There are more different chess games than atoms in the galaxy.These are merely trivial problems that illustrate the problem of programming a chess-playing computer, which is in fact an extremely difficult problem to solve.It should come as no surprise that even the most well-thought-out programs are no match for chess grandmasters. The role of a programmer is in fact similar to that of a father who teaches his son how to play chess.He told the computer the main moves in outline, rather than telling it all the moves that would work for every opening.Instead of saying it literally in the language we use every day, like walking a diagonal line, he said it in the language of mathematics, like new coordinates come from old coordinates, the program is to add the same to the old coordinate X and the old coordinate y constants, but their signs do not have to be the same.The language actually used is of course more concise.Then he can program some advice, using the same mathematical or logical language, to the effect that if expressed in our everyday language, it is nothing more than not exposing your king to the enemy, or some practical tricks, Such as one horse for two purposes, attacking the opponent's two sons at the same time.These specific chess moves are intriguing, but it would be too far from the topic to talk about them.The important thing is that after the computer has made the first move, it needs to operate independently, and cannot expect any further instructions from its master.All the programmer can do is deploy the computer to the best of his ability in advance, striking the right balance between the provision of specific knowledge and hints of strategy and tactics. Genes also control the behavior of their survival machines, but not directly, like fingers on puppets, but through indirect pathways, like computer programmers.What the genes can do is limited to the deployment in advance, and they can only stand by when the survival machines operate independently later.Why are genes so devoid of initiative?Why don't they hold the reins tightly and direct the behavior of survival machines at any time?This is because of the difficulty caused by time lag.There is a science fiction novel that illustrates this problem very cleverly by means of analogy.This gripping novel is A in Andromeda by Fred Hoyle and John Elliot.Like all good sci-fi, it has some interesting scientific arguments to back it up.Yet, strangely enough, the novel seems to deliberately avoid discussing one of its most important scientific points, leaving the reader to imagine for himself.If I tell it all here, I think the two authors will not be offended. There is a civilized world in the Andromeda constellation two hundred light-years away from us.People there want to spread their culture to some distant worlds.What is the best way to do it?It is impossible to send someone directly to go once.In the universe, your maximum speed from one place to another cannot theoretically exceed the upper limit of the speed of light. What's more, due to the limitation of mechanical power, the maximum speed is much lower than the speed of light.In addition, in the universe, there may not be so many worlds worth visiting. Do you know which direction to go in to make this trip worthwhile?Radio waves are an ideal means of communicating with the rest of the universe because, if you have enough power to broadcast your radio signal in all directions instead of beaming it in one direction, there are a very large number of worlds that can receive your radio waves (the number of Proportional to the square of the distance traveled by the wave).Radio waves travel at the speed of light, which means that it takes two hundred years for a signal from Andromeda to reach Earth.Such a long distance makes it impossible to communicate between the two places.Even if every message sent from the earth was transmitted by twelve generations of people, it would be a waste of money and money to try to communicate with people so far away. This is a practical problem that we will soon face.Between the Earth and Mars, radio waves take about four minutes to travel.There is no doubt that astronauts must change their conversation habits in the future. They can no longer speak like you and me, but must use long monologues and talk to themselves.This type of call is not so much a conversation as a communication.As another example, Roger Payne points out that there are certain curious properties of the acoustics of the ocean which mean that the unusually loud songs of humpback whales could theoretically be heard anywhere in the world if they were swimming. at a certain depth in the sea.Whether humpback whales actually talk to each other over long distances is unknown.If anything, they're in the same predicament as astronauts on Mars.According to the speed of sound propagation in the water, it takes about two hours for the humpback whale's song to reach the other side of the Atlantic Ocean and then wait for the other party's song to come back.This, it seems to me, is the reason why a humpback whale's solo usually lasts eight minutes without repetition, and then repeats itself many times, each cycle lasting about eight minutes. The Andromedans in the novel do the same.They knew that there was no practical point in waiting for an echo from the other party, so they put together what they wanted to say, compiled it into a complete long message, and then broadcast it to space, each time lasting for several months, and then repeated it continuously.Their message, however, is very different from that of the whales.The Andromedan message was written in electrical code, instructing others how to build and program a giant computer.The telegram was, of course, not in human language.But to skilled cryptographers, almost any cipher can be broken; especially if the cipher's designers intended it to be easy to break.This telegram was first intercepted by the radio telescope of Bank (JodreII Bank), and the telegram was finally translated.According to the instructions, the computer was finally built and its program was put into practice.The result was almost catastrophic for humanity, for the Andromedans did not have altruistic intentions toward everyone.This computer has pretty much brought the entire world under its dictatorship.In the end, the protagonist smashed the computer with a sharp ax at the critical moment. The interesting question, from our point of view, is in what sense we can say that the Andromedans were manipulating affairs on Earth.They have no direct control over what they do to the computer at any time.In fact, they didn't even know that the computer had been built, because it took two hundred years for the information to reach them.The computer makes decisions and takes actions completely independently.It can no longer even ask its master general strategic questions.Since the 200-year barrier is insurmountable, all instructions must be incorporated into the procedure in advance.In principle, this is roughly the same program as would be required for a computer to play chess, but with greater flexibility and adaptability to local conditions.This is because such a program would have to be specific not only to conditions on Earth, but also to worlds of all kinds with advanced technologies whose specific conditions the Andromedans had no idea. Just as the Andromedans had to have a computer on Earth to make their day-to-day decisions, our genes had to build a brain.But genes aren't just Andromedans giving out coded instructions, they're instructions themselves, and the reason they can't direct us puppets is the same: time lag.Genes function by controlling the synthesis of proteins.This is a powerful means of manipulating the world, but it will take time to bear fruit.Growing an embryo takes months of patiently manipulating proteins.On the other hand, the most important thing about behavior is the quickness of it.The unit of time used to measure behavior is not months but seconds or fractions of a second.Something happens in the outside world: an owl flies overhead, the rustling grass exposes the prey, and in a split second the nervous system jerks, the muscles leap; the prey escapes or is sacrificed.Genes don't have reaction times like this.Like the Andromedans, the genes had to do what they could to pre-deploy everything, building themselves a fast executive computer.Give it the laws of as many situations as the genes can anticipate, and advise them accordingly.But life is as unpredictable as a chess game, and it is unrealistic to foresee everything in advance.Like the programmer of a chess game, the instructions of genes to a survival machine cannot be specific and subtle, but only general strategies and tricks applicable to survival. As Young pointed out, genes must perform tasks like making predictions about the future.While the embryonic survival machine is being built, the dangers and problems it may encounter in its later life are unknown.Who can predict what carnivores will crouch in which bushes to attack it, or what fast-legged live snacks will suddenly appear in front of it and meander by?Humans can't predict these problems, and genes can't do anything about them.But certain generalities are foreseeable.Polar bear genes can safely know in advance that their unborn survival machines will have a frigid environment.This prediction is not the result of genetic thinking.They never think: they just prepare their coats in advance, as they have always done in some previous bodies.That's why they still exist in the gene pool.They also foresee that the earth will be covered with snow, and this foresight is reflected in the color of their fur.The gene makes the fur white, thus achieving camouflage.If the climate in the Arctic changes so drastically that polar bear cubs find themselves born in tropical deserts, the genetic predictions will be wrong.They will pay for it.The cubs die, and with them the genes in their bodies. In a complex world, predicting the future is risky.Every decision a survival machine makes is a gamble, and it is the responsibility of genes to program the brain in advance so that the decisions it makes will more than likely lead to positive outcomes.In the casino of evolution, the chips at play are survival, strictly speaking, the survival of genes.But in general, and as a reasonable approximation, it can also be said to be the survival of the individual.If you go down to the waterhole to drink, the risk of being eaten by the predators waiting at the waterhole increases.If you don't go, you will eventually die of thirst.Whether you go or not, risks exist.You have to make decisions that give your genes the best chance of survival.Perhaps the best thing to do is to hold back until you absolutely have to and go down for a quick drink so that you don't need to drink water for a long time.This way, you reduce the number of trips to the watering hole, but when you finally have to drink, you have to put your head down and drink for a long time.Another risky way is to drink less and run more, that is, run to have a drink or two, and then run back immediately, so that a few more runs can also solve the problem.Which risk-taking strategy is the best depends on various complex circumstances, among which the hunting habits of carnivores are also an important factor.In order to achieve maximum effect, carnivores are also constantly improving their hunting habits.Therefore, some form of trade-off between the pros and cons of the various possibilities is necessary.But we certainly don't necessarily think of these animals as consciously weighing pros and cons.We just have to believe that if the genes of those animals built the sharp brains that make them more likely to win the bets; then, as a direct consequence, the animals are more likely to survive and the genes reproduce. We can take the betting metaphor a little further.A gambler must consider three main quantities: stake, chance, and winnings.Gamblers are willing to place big bets if the winnings are huge.An all-or-nothing gambler has the opportunity to make a lot of money.He could lose it all, of course, but on average, a person who bets big has little or no advantage over someone who bets small for small wins.There are also similarities between speculators who buy short and sell short on the exchanges and investors who play it safe.In some respects, the metaphor of a stock exchange is more apt than a casino, where wins and losses are rigged and the house always wins in the end (technically, this means that those who bet big lose more than those who bet small). more, and those who play small bets are poorer than those who do not bet. But in a sense the case of not betting is inappropriate for the present topic).That aside, there seem to be reasons for both big and small bets.Are there any animals that make big bets, or are there animals that are more conservative?As we shall see in Chapter 9, one can often think of male animals as high-stakes, high-risk gamblers, and females as steady investors, especially when males are mates with each other. Among species in which males and females compete.The naturalist who reads this book can think of some species that might be called high-stakes, high-risk, and others that are more conservative.This is where I turn to the more general topic of how genes make predictions about the future. In some unpredictable environments, how genes can predict the future is a difficult problem. One way to solve this problem is to give survival machines a learning ability in advance.To do this, genes can be programmed in the form of instructions to their survival machinery that the following will bring benefits: a sweet taste in the mouth, a high sex drive, a moderate temperature, a smiling child, and so on.And the following will bring unpleasantness: all kinds of pain, nausea, empty belly, crying child, etc.If you happen to do something and an unpleasant situation arises after it, don't do it again; on the other hand, repeat anything that does you good.A procedure thus prepared has the advantage of greatly reducing the number of elaborate rules that had to be incorporated into the original procedure, while at the same time being able to cope with changes in circumstances whose details were not foreseen in advance.On the other hand, it is still necessary to make some predictions.In our example, the genes figured that eating sugar and mating might be good for the genes' survival, in the sense that sweetness in the mouth and arousal are good.But according to this example, they cannot foresee that saccharine and self-abuse may also bring them satisfaction.Nor can they foresee the dangers of sugar overeating in our somewhat unnaturally plentiful sugar environment. Learning strategies has been used in some programs for computers playing chess.These programs do improve over time as computers play against humans or against other computers.Although they have a library of rules and tactics, they also have a small random tendency pre-programmed into their decisions.They record past decisions, and each time they win a game, they slightly increase the weight of the tactic that led to victory in this game, so that the computer is more likely to use the same tactic again next time. One of the most interesting ways to predict the future is through simulations.A general who wants to know whether a certain military plan is superior to other alternatives faces the problem of making predictions.The weather, troop morale, and possible enemy countermeasures are all unknowns.One way to know if the plan is feasible is to try it out and see how it works.It is not advisable, however, to try out every conceivable plan, since the number of young people willing to die for their country is limited, and the number of possible plans is enormous.Exercises against imaginary enemies can also test the practicality of various plans, which is better than doing it with real swords and guns.The exercise can take the form of an all-out war between the North and the South, using empty shells.But even that takes a lot of time and material.A less expensive way is to use toy soldiers and tanks to move around on the large map for maneuvers. In recent years, computers have taken over most of the simulation functions, not only in military strategy, but in all fields such as economics, ecology, sociology, etc., where predictions about the future must be made.It uses the technique of building a model of something in the world inside a computer.That doesn't mean that, if you lift the computer's lid off, you can see a miniature imitation of the same thing as the simulated object.In a chess-playing computer, there is nothing in the memory device that can be seen as a chessboard with knights and pawns in their positions.Some are just lines of electronic code representing the board and the positions of the various pieces.對我們來說，地圖是世界某一部分的平面縮影。在計算機裡面，地圖通常是以一系列城鎮和其他地點的名字來代表的。每個地點附有兩個數字它的經度和緯度。計算機的電腦實際上如何容納它這個世界的模型是無關緊要的。重要的是容納的形式允許它操縱這個模型，進行操作和試驗，並以計算機操作員能夠理解的語言匯報運算的結果。通過模擬技術，以模型進行的戰役可以得出勝負，模擬的班機可以飛行或墜毀，經濟政策可以帶來繁榮或崩潰。無論模擬什麼，計算機的整個運算過程只需實際生活中極小的一部分時間。當然，這些反映世界的模型也有好壞之分，而且即使是上好的模型也只能是近似的。不管模擬得如何逼真也不能預測到將要發生的全部實際情況，但好的模擬肯定遠勝於盲目的試驗和誤差。我們本來可以把模擬稱為代替性的試驗和誤差，不幸的是，這個術語早為研究老鼠心理的心理學家所優先佔用了。 如果模擬是這樣一個好辦法，我們可以設想生存機器本該是首先發現這個辦法的，早在地球上出現人類以前，生存機器畢竟已經發明了人類工程學的許多其他方面的技術：聚焦透鏡和拋物面反射鏡、聲波的頻譜分析、伺服控制系統、聲納、輸入信息的緩衝存儲器以及其他不勝枚舉的東西，它們都有長長的名字，其具體細節這裡不必細說。模擬到底是怎麼一回事呢？我說，如果你自己要作出一個困難的決定，而這個決定牽涉到一些將來的未知量，你也會進行某種形式的模擬。你設想在你採取各種可供選擇的步驟之後將會出現的情況。你在腦子裡樹立一個模型，這個模型並不是世上萬物的縮影，它僅僅反映出依你看來是有關的範圍有限的一組實體。你可以在心目中看到這些事物的生動形象，或者你可以看到並操縱它們已經概念化了的形象。無論怎樣，不會在你的腦子裡出現一個實際上佔據空間的、反映你設想的事物的模型。但和計算機一樣，你的腦子怎樣表現這個模型的細節並不太重要，重要的是你的腦子可以利用這個模型來預測可能發生的事物。那些能夠模擬未來事物的生存機器，比只會在明顯的試驗和誤差的基礎上積累經驗的生存機器要棋高一著。問題是明顯的試驗既費時又費精力，明顯的誤差常常帶來致命的後果。模擬則既安全又迅速。 模擬能力的演化似乎終於導致了主觀意識的產生。其所以如此，在我看來，是當代生物學所面臨的最不可思議的奧秘。沒有理由認為電子計算機在模擬時是具有意識的，儘管我們必須承認，有朝一日它們可能具有意識。意識之產生也許是由於腦子對世界事物的模擬已達到如此完美無缺的程度，以致把它自己的模型也包括在內。顯然，一個生存機器的肢體必然是構成它所模擬的世界的一個重要部分；可以假定，為了同樣理由，模擬本身也可以視為是被模擬的世界的一個組成部分。事實上，自我意識可能是另外一種說法，但我總覺得這種說法用以解釋意識的演化是不能十分令人滿意的，部分原因是它牽涉到一個無窮盡的復歸問題如果一個模型可以有一個模型，那麼為什麼一個模型的模型不可以有一個模型呢？ 不管意識引起了哪些哲學問題，就本書的論題而言，我們可以把意識視為一個進化趨向的終點，也就是說，生存機器最終從主宰它們的主人即基因那裡解放出來，變成有執行能力的決策者。腦子不僅負責管理生存機器的日常事務，它也取得了預測未來並作出相應安排的能力。它甚至有能力拒不服從基因的命令，例如拒絕生育它們的生育能力所容許的全部後代。但就這一點而言，人類的情況是非常特殊的，我們在下面將談到這個問題。 這一切和利他行為和自私行為有什麼關係呢？我力圖闡明的觀點是，動物的行為，不管是利他的或自私的，都在基因控制之下。這種控制儘管只是間接的，但仍然是十分強有力的。基因通過支配生存機器和它們的神經系統的建造方式而對行為施加其最終的影響。但此後怎麼辦，則由神經系統隨時作出決定。基因是主要的策略制定者；腦子則是執行者。但隨著腦子的日趨高度發達，它實際上接管了越來越多的決策機能，而在這樣做的過程中運用諸如學習和模擬的技巧。這個趨勢在邏輯上的必然結果將會是，基因給予生存機器一個全面的策略性指示：請採取任何你認為是最適當的行動以保證我們的存在。但迄今為止還沒有一個物種達到這樣的水平。 和計算機類比以及和人類如何作出決定進行類比確實很有意思。但我們必須回到現實中來，而且要記注，事實上進化是一步一步通過基因庫內基因的差別性生存來實現的。因此，為使某種行為模式利他的或自私的能夠演化，基因庫內操縱那種行為的基因必須比操縱另外某種行為的、與之匹敵的基因或等位基因有更大的存活可能性。一個操縱利他行為的基因，指的是對神經系統的發展施加影響，使之有可能表現出利他行為的任何基因。我們有沒有通過實驗取得的證據，表明利他行為是可遺傳的呢？No.但這也是不足為奇的，因為到目前為止，很少有人對任何行為進行遺傳學方面的研究。還是讓我告訴你們一個研究行為模式的實例吧！這個模式碰巧並不帶有明顯的利他性，但它相當複雜，足以引起人們的興趣。這是一個說明如何繼承利他行為的典型例子。 蜜蜂有一種叫腐臭病（foul brood）的傳染病。這種傳染病侵襲巢室內的幼蟲。養蜂人馴養的品種中有些品種比其他的品種更易於感染這種病，而且至少在某些情況下各品系之間的差異證明是由於它們行為上的不同。有些俗稱衛生品系的蜜蜂能夠找到受感染的幼蟲，把它們從巢室裡拉出來並丟出蜂房，從而迅速地撲滅流行病。那些易感染的品系之所以易於染病正是因為它們沒有這種殺害病嬰的衛生習慣。實際上這種衛生行為是相當複雜的。工蜂必須找到每一患病幼蟲所居住的巢室，把上面的蠟蓋揭開，拉出幼蟲，把它拖出蜂房門，並棄之於垃圾堆上。 由於各種理由，用蜜蜂做遺傳學實驗可以說是一件相當複雜的事情。工蜂自己一般不繁殖，因此你必須以一個品系的蜂后和另外一個品系的雄蜂雜交，然後觀察養育出來的子代工蜂的行為。羅森比勒（W．C．Rothenbunler）所作的實驗就是這樣進行的。他發現第一代子代雜交種的所有蜂群都是不衛生的：它們親代的衛生行為似乎已經消失，儘管事實上衛生的基因仍然存在，但這些基因已變成隱性基因了，像人類的遺傳藍眼睛的基因一樣。羅森比勒後來以第一代的雜交種和純粹的衛生品系進行回交（當然也是用蜂后和雄蜂），這一次他得到了絕妙的結果。子代蜂群分成三類：第一類表現出徹底的衛生行為，第二類完全沒有衛生行為，而第三類則是拆衷的。這一類蜜蜂能夠找到染病的幼蟲，揭開它們的蠟蜂巢的蓋子，但只到此為止，它們並不扔掉幼蟲。據羅森比勒的猜測，可能存在兩種基因，一種是進行揭蓋的，另一種是扔幼蟲的。正常的衛生品系兩者兼備，而易受感染的品系則具有這兩種基因的等位基因它們的競爭對手。那些在衛生行為方面表現為拆衷的雜交種，大概僅僅具有揭蓋的基因（其數量是原來的兩倍）而不具有扔幼蟲的基因。羅森比勒推斷，他在實驗中所培育出來的，顯然完全是不衛生的蜂群裡可能隱藏著一個具有扔幼蟲的基因的亞群，只是由於缺乏揭蓋子基因而無能為力罷了。他以非常巧妙的方式證實了他的推斷：他自己動手把蜂巢的蓋子揭開。果然，蠟蓋揭開之後，那些看起來是不衛生的蜜蜂中有一半馬上表現出完全正常的把幼蟲扔掉的行為。 這段描述說明了前面一章提到的若干重要論點。它表明，即使我們對把基因和行為連接起來的各種胚胎因素中的化學連接一無所知，我們照樣可以恰如其分地說操縱某種行為的基因。事實上，這一系列化學連接可以證明甚至包括學習過程。例如，揭蠟蓋基因之所以能發揮作用，可能是因為它首先讓蜜蜂嘗到受感染的蜂蠟的味道。就是說，蜂群會發覺把遮蓋病仔的蠟蓋吃掉是有好處的，因此往往一遍又一遍地這樣做。即使基因果真是這樣發揮作用的，只要具有這種基因的蜜蜂在其他條件不變的情況下終於進行揭蓋活動，而不具有這種基因的蜜蜂不這樣做，那麼，我們還是可以把這種基因稱為揭蓋子的基因。 第二，這段描述也說明了一個事實，就是基因在對它們共有的生存機器施加影響時是合作的。扔幼蟲的基因如果沒有揭蓋基因的配合是無能為力的，反之亦然。不過遺傳學的實驗同樣清楚地表明，在貫串世世代代的旅程中，這兩種基因基本上是相互獨立的。就它們的有益工作而言，你盡可以把它們視為一個單一的合作單位；但作為複製基因，它們是兩個自由的、獨立的行為者。 為了進行論證，我們有必要設想一下操縱各種不大可能的行為的基因。譬如我說有一種假設的操縱向溺水的同伴伸出援手的行為的基因，而你卻認為這是一種荒誕的概念，那就請你回憶一下上面提到的衛生蜜蜂的情況吧。要記住，在援救溺水者所涉及的動作中，如一切複雜的肌肉收縮，感覺整合，甚至有意識的決定等等，我們並不認為基因是唯一的一個前提因素。關於學習、經驗以及環境影響等等是否與行為的形成有關這個問題我們沒有表示意見。你只要承認這一點就行了：在其他條件不變的情況下，同時在許多其他的主要基因在場，以及各種環境因素發揮作用的情況下，一個基因，憑其本身的力量比它的等位基因有更大的可能促使一個個體援救溺水者。這兩種基因的差別歸根結底可能只是某種數量變數的差異。有關胚胎發育過程的一些細節儘管饒有風趣，但它們與進化的種種因素無關。洛倫茨明確地闡明了這一點。 基因是優秀的程序編製者，它們為本身的存在而編製程序。生活為它們的生存機器帶來種種艱難險阻，在對付這一切艱難險阻時這個程序能夠取得多大的成功就是判定這些基因優劣的根據。這種判斷是冷酷無情的，關係到基因的生死存亡。下面我們將要談到以表面的利他行為促進基因生存的方式。但生存機器最感關切的顯然是個體的生存和繁殖，為生存機器作出各種決定的腦子也是如此。屬同一群體的所有基因都會同意將生存和繁殖放在首位。因此各種動物總是竭盡全力去尋找並捕獲食物，設法避免自己被抓住或吃掉；避免罹病或遭受意外；在不利的天氣條件下保護自己；尋找異性伴侶並說服它們同意交配；並以一些和它們享受的相似的優越條件賦予它們的後代。我不打算舉出很多例子如果你需要一個例證，那就請你下次仔細觀察一下你看到的野獸吧。但我卻很想在這裡提一下一種特殊的行為，因為我們在下面談到利他行為與自私行為時必須再次涉及這種行為。我們可以把這種行為概括地稱為聯絡（communication）。 我們可以這樣說，一個生存機器對另一個生存機器的行為或其神經系統的狀態施加影響的時候，前者就是在和後者進行聯絡。這並不是一個我打算堅持為之辯護的定義，但對我們目前正在探討的一些問題來說，這個定義是能夠說明問題的。我所講的影響是指直接的、偶然的影響。聯絡的例子很多：鳥、蛙和蟋蟀的鳴唱；狗的搖動尾巴和豎起長頸毛；黑猩猩的露齒而笑；人類的手勢和語言等。許許多多生存機器的行動，通過影響其他生存機器的行為的間接途徑，來促進其自身基因的利益。各種動物千方百計地使這種聯絡方式取得成效。鳥兒的鳴唱使人們世世代代感到陶醉和迷惘。我上面講過的弓背鯨的歌聲表達出更其高超的意境，同時也更迷人。它的音量宏大無比，可以傳到極其遙遠的地方，音域廣闊，從人類聽覺能夠聽到的亞音速的低沉的隆隆聲直到超音速的、短促的刺耳聲。螻蛄之所以能發出宏亮的歌聲，這是因為它們在泥土中精心挖成雙指數角狀擴音器一樣的土穴，在裡面歌唱，唱出的歌聲自然得到擴大。在黑暗中翩翩起舞的蜂群能夠為其他覓食的蜂群準確地指出前進的方向以及食物在多遠的地方可以找到。這種巧妙的聯絡方法只有人類的語言可以與之比美。 動物行為學家的傳統說法是，聯絡信號之逐步完善對發出信號者和接收信號者都有裨益。譬如說，雛雞在迷途或受凍時發出的尖叫聲可以影響母雞的行為。母雞聽到這種吱吱啁啁的叫聲後通常會應聲而來，把小雞領回雞群。我們可以說，這種行為的形成是由於它為雙方都帶來好處；自然選擇有利於迷途後會吱吱啁啁叫的雛雞，也有利於聽到這種叫聲後隨即作出適當反應的母雞。 如果我們願意的話（其實無此必要），我們可以認為雛雞叫聲之類的信號具有某種意義或傳達某種信息。在這個例子裡，這種呼喚聲相當於我迷路了！我在第一章中提到的小鳥發出的報警聲傳遞了老鷹來了！這一信息。那些收到這種信息並隨即作出反應的動物無疑會得到好處。因此，這個信息可以說是真實的。可是動物會發出假的信息嗎？它們會扯謊嗎？ 說動物說謊這種概念可能會令人發生誤解，因此我必須設法防止這種誤解的產生。我記得出席過一次比阿特麗斯（Beatrice）和加德納（Alan Gardner）主講的一次講座，內容是關於他們所訓練的遇逸聞名的會說話的黑猩猩華舒（她以美國手勢語表達思想。對學習語言的學者來說，她的成就可能引起廣泛的興趣）。聽眾中有一些哲學家，在講座結束後舉行的討論會上，對於華舒是否會說謊這個問題他們費了一番腦筋。我猜想，加德納夫婦一定有些納悶，為什麼不談談其他更有趣的問題呢？I'm feeling it too.在本書中，我所使用的欺騙、說謊等字眼只有直截了當的含義，遠不如哲學家們使用的那麼複雜。他們感興趣的是有意識的欺騙。而我講的僅僅是在功能效果上相當於欺騙的行為。如果一隻小鳥在沒有老鷹出現的情況下使用鷹來了這個信號，從而把它的同伴都嚇跑，讓它有機會留下來把食物全都吃掉，我們可以說它是說了謊的。我們並不是說它有意識地去欺騙。我們所指的只不過是，說謊者在犧牲其同伴的利益的情況下取得食物。其他的小鳥之所以飛走，這是因為它們在聽到說謊者報警時作出在真的有鷹出現的情況下那種正常反應而已。 許多可供食用的昆蟲，如前一章提到的蝴蝶，為了保護自己而模擬其他味道惡劣的或帶刺的昆蟲的外貌。我們自己也經常受騙，以為有黃黑條紋相間的食蚜蠅就是胡蜂。有些蒼蠅在模擬蜜蜂時更是惟妙惟肖，肉食動物也會說謊。琵琶魚在海底耐著性子等待，將自己隱蔽在周圍環境中，唯一觸目的部分是一塊像蟲一樣蠕動著的肌肉，它掛在魚頭上突出的一條長長的釣魚竿末端。小魚游近時，琵琶魚會在小魚面前抖動它那像蟲一樣的鉤餌，把小魚引到自己的隱而不見的嘴巴旁。大嘴突然張開，小魚被囫圇吞下。琵琶魚也在說謊。它利用小魚喜歡游近像蟲一樣蠕動著的東西這種習性。它在說，這裡有蟲任何受騙上當的小魚都難逃被吞掉的命運。 有些生存機器會利用其他生存機器的性慾。蜂蘭（bee orchid）會引誘蜜蜂去和它的花朵交配，因為這種蘭花活像雌蜂。蘭花必須從這種欺騙行為中得到的好處是傳播花粉，因為一隻分別受到兩朵蘭花之騙的蜜蜂必然會把其中一朵蘭花的花粉帶給另外一朵。螢火蟲（實際上是甲蟲）向配偶發出閃光來吸引它們。每一物種都有其獨特的莫爾斯電碼一樣的閃光方式，這樣，不同物種之間不會發生混淆不清的現象，從而避免有害的雜交。正像海員期待發現某些燈塔發出的獨特的閃光模式一樣，螢火蟲會尋找同一物種發出的密碼閃光模式。Photuris屬的螢火蟲雌蟲發現如果它們模擬Photinus屬的螢火蟲雌蟲的閃光密碼，它們就能把Photinus屬的螢火蟲雄蟲引入彀中。 Photuris屬的雌蟲就這樣做了。當一隻Photinus屬的雄蟲受騙接近時，雌蟲就不客氣地把它吃掉。說到這裡，我們自然會想起與此相似的有關塞王（Siren）和洛勒萊（Lorelei）的故事，但英國西南部的康瓦耳（Cornwall）人卻會追憶昔日那些為行劫而使船隻失事的歹徒，他們用燈籠誘船觸礁，然後劫掠從沉船中散落出來的貨物。 每當一個聯絡系統逐漸形成時，這樣的風險總會出現：即某些生物利用這個系統來為自己謀私利。由於我們一直受到物種利益這個進化觀點的影響，因此我們自然首先認為說謊者和欺騙者是屬於不同的物種的：捕食的動物，被捕食的動物，寄生蟲等等。然而，每當不同個體的基因之間發生利害衝突時，不可避免地會出現說謊、欺騙等行為以及聯絡手段用於自私的目的的情況。這包括屬於同一物種的不同個體。我們將會看到，甚至子女也要欺騙父母，丈夫也要欺騙妻子，兄弟倆也要相互欺騙。 有些人相信，動物的聯絡信號原來是為了促進相互的利益而發展的，只是後來為壞分子所利用。這種想法畢竟是過於天真。實際的情況很可能是：從一開始，一切的動物聯絡行為就合有某種欺詐的成分，因為所有的動物在相互交往時至少要牽涉到某種利害衝突。我打算在下面一章介紹一個強有力的觀點，這個觀點是從進化的角度來看待各種利害衝突的。