INTRODUCTION

Imagine you’re God*, and the year is 13 billion BC (give or take a few billion). You’re kind of bored so you decide to build a universe. You set a few rules for the new universe, like that it will have 3 dimensions of space, one of time, and maybe lots of other hidden ones. After that, you’ll just let the program unfold, and see what happens. You make a nice big bang to start it off. The explosion is at about 100 million trillion degrees celsius, and it expands (if that's the right way to conceptualize a Universe which seemingly isn't moving into anything; space is actually being created) at many million kilometres per second. At the very start, the forces and particles are very different from what they are now: there are no atoms, and there’s a whole lot of matter and antimatter about; these will mostly devour each other quickly.

* Who I don't believe in by the way

You go over to one of your angels. He hasn’t seen a Universe before, and you say to him "have a look at this new universe I’ve made. What do you think of it?". He might say "well, that’s pretty amazing, God, but don’t you think it’s a bit pointlessly violent?". Then you say to him "take a guess about this universe. What do you think will happen with it? What will it be like in 10 or 15 billion years? Do you think anything interesting will be happening?".

He’s just an angel, so he doesn’t know everything like you do. What would his answer be? I would imagine that one of his last guesses would be that intelligent life would emerge. The starting point is brutal and chaotic. But somehow, some of the particles thrown out in that explosion have become larger and more complex, and formed atoms which can be grouped in coalitions of many trillions. Some of those atom coalitions are now talking to each other, their pets, or their gods. Other coalitions patrol the crushing blackness of the ocean depths; yet others probe tendrils into the earth, and slowly race towards a spare patch of sunlight.

Within these coalitions is a spectacular richness of organisation. In the human head, for example, hundreds of millions of particles interpret the chaos of light waves that enters the structures in our heads which are designed to detect electromagnetic waves. I’m talking about eyes of course. Within milliseconds, these particles communicate via massive chains of particles with yet others that detect and interpret slight vibrations in the air or sea. Other atom clusters reach decisions by somehow linking with just the right particles, which have been quietly holding representations of events that occurred in the past. And so on. And what I’ve just said is a complete simplification of what these tiny, mindless particles team up to do every millisecond of our lives.

Love, thought, hatred, speech, and consciousness exist. The wildest claims of futurologists are easily matched by the stunning fact that they exist (or, for that matter, that anything at all does).

The source of them all is a small lump of flesh. The last time you felt over the moon or suicidal, that was because of something happening in this lump. Inside your skull lie instructions for walking, loving, thinking, hatred, dreams, and speech. Because of its intricate pathways, you are conscious. What kind of mechanism is it that can produce this?

Well, after all that buildup, I can't give you a proper answer. After all, I'm talking about the most complex mechanism in the known universe. But I will talk a little bit about some things I find interesting about brains and intelligence.

When one compares today’s lifeforms to their predecessors in the (very) distant past - say a billion or 500 million years ago - one is left in no doubt that today, there is far more complexity than all those generations ago. However, this trend is not one which always dominates; there are very powerful countervailing forces. One of these is the need for economy.

In the final draft of his article ‘Folk Biology and the Anthropology of Science’, Scott Atran observes that ‘the actual domain of frog food-getting intelligence involves tongue flicking at dark points passing along a frog’s field of vision, whereas the proper domain is more about catching flies (Sperber 1994)’. If a bee or wasp flies past the frog, it will not react; and it will starve to death if surrounded by immobile flies. It is deaf to most of the sounds in its environment; all that its ears can hear is the sounds of other frogs, those of its predators, and those of other phenomena (such as people) which just happen to act in ways which frogs can detect. Frogs live in a comparatively simple world of moving dots, cold, heat, water, other frogs, bad guys, and so on (I said comparatively simple). Would it not be better for them to have a fuller understanding of what's really happening in their environment? Not necessarily.

In evolutionary terms, our primary aim, and that of all animals and plants, is to aid in the propagation of the genes which have organised our construction, and which will be able to organise the construction of our descendants, usually through reproduction*. However, clearly there are few animals which think to themselves ‘I must reproduce’; rather, they feel a desire to have sex. Unwanted teenage pregnancies show how this dichotomy between an individual’s goals and the ‘goals’ of their genes is also common in homo sapiens. The teenager's genes want to make copies of themselves; but although she enjoys sex, she doesn't want to get pregnant. Similarly, I know of few people who think to themselves: ‘now I will eat so that my body can reconstruct itself’, or ‘now I will breathe in order to provide the energy which my body needs in order to function’. We normally think something along the lines of: ‘I’m dying for a shag’, ‘I’m starving’, or ‘Jesus, I could do with a break’.

* there are exceptions to this - for example, the sterile castes in the social insects

Why is our mental life - and, to an even greater extent, that of other animals - taken up by goals which are subsidiary to the real goal - self-propagation - which evolution has etched into our genes?

The relationship between gene objectives and subjective desires goes something like this:

You may have noticed that as I've progressed down through this (hardly exhaustive) list, the terminology has become more ‘down home’. Despite my use of linguistic sleight (or clumsiness) of hand in order to hammer the point home, to a certain extent this happened naturally, because our subjective experiences correspond more to the latter end of the scale.

Why is this? In a word, economy. Flicking one’s tongue at rapidly-moving black dots does the job for frogs; granted, they consequently fail to appreciate the majesty and complexity (and ickyness) of the fly - but their mental operations are far cheaper in terms of energy and materials than are those of hypothetical genius frogs with great insight and perspicacity.

One might think it a (fatal) waste for genes to construct a creature which, instead of thinking,

‘Gee, I’m real horny’, thought

"well, all those double helixes nestling in all the cells of my body ‘want’ (in a manner of speaking) to be reproduced. Should I care? If so, how should I go about it?".

However, despite the pressure - enforced on pain of death, aka natural selection - to economize, a similar question is now being asked by a 1,400- gram, fabulously intricate energy-guzzler (Paddy Carroll’s brain). 1,400 grams may not seem large, because it’s within the size range we are accustomed to operating in; however, in the more relevant terms of the size of its constituents, the human brain is enormous. It has more than 100 billion neurons, with an average of 1000 synapses (junctions) per neuron, and more than 50 kinds of synapse. We humans are not medium-sized; we are colossal. Are our vast brain-machines uneconomical? My motive for asking this is a great curiosity as to whether we might expect intelligent life to have evolved (by natural selection) elsewhere in our giant universe.

The answer is that clearly, the human brain is highly economical - we humans have used it to gain a decidedly favourable position on the planet. Our genes have become entrepreneurs: high investment (made by what one might call the slaves they construct, inhabit, and to some extent control), even higher profit. Other genes, however, still run ‘corner shops’; unlike our friendly neighbourhood grocer, they (micro-organisms) are in no danger of being superseded by the big chains (get it - supermarket chains/longer strands of DNA?). Does this lavish expenditure mean that economy is no longer a major factor in the assembly of the human brain?

THE HUMAN'S TRUNK:
Did we have to get smart?

It is often argued that intelligence - and/or high intelligence - was no more inevitable than was the elephant's trunk; it is only one possible means of achieving reproductive success.

Nature does not value anything which does not improve reproductive capacity, a point which is illustrated by the life cycle of the sea squirt. This creature undergoes a free-floating stage, after which it settles down to a sedentary lifestyle. At this latter stage, the creature has no need for the intelligence that helped it navigate. However, it does have a use for its brain; it is a fine source of nourishment, and the squirt guzzles it forthwith¹.

¹ Leda Cosmides & John Tooby: 'Evolutionary Psychology: A Primer'

The argument against inevitability cannot be dismissed lightly; there are many preconditions for intelligence, and still more for the flexible intelligence possessed by humans. Two prerequisites are size (an ant cannot have a 500-cc brain) and endothermy (aka warm-bloodedness: brains guzzle energy, and thus require a high metabolism). It is not in dispute that complexity is one of the things which evolution sometimes selects for; increasing the division of labour within an organism can often promote efficient reproduction. However, many commentators - among them the outstanding cognitive scientist Steven Pinker - have argued that beyond a certain point, increases in intelligence may usually militate against an organism's reproductive capacity. In other words - and I'm not quoting anyone here - increases in brain size are likely to reach a point of diminishing returns. In this view, there is no evolutionary trend towards high intelligence. A certain amount is useful, and naturally results from large size and endothermy; however, the evolution of human-level intelligence requires a highly improbable confluence of abilities.

Humans have the following characteristics, some of which have resulted from the very specialised niches exploited by our ancestors: stereoscopic vision; colour vision, opposable thumbs, … .
If all these are prerequisites for human-level intelligence and ingenuity, then the probability of creatures such as ourselves arising may be remote.

Several questions need to be answered. For example, did warm-bloodedness develop purely because endotherms could survive the cold better, and penetrate colder niches than ectotherms? If one examines evolution, and factors out the primate lineage, increases in body size, and the effects of global catastrophes, can one still detect a move towards higher intelligence? If so, is this trend limited by energy constraints and by the incompatibility of high intelligence with the characteristics of all credible evolutionary lineages*?

* Too many questions - it's impossible for me to answer them all.

High intelligence is only one way among many by which animals can make a living in the world; others include: superior speed, hearing, vision, smell, dodging skill, claws, teeth, venom, armour, and concealment; greater fecundity; changes in size; hunting cooperation; aggregation of prey species into groups to increase 'sensory coverage'; nocturnal hunting; and so on. For example, a grazer does not need intelligence to find grass; its ability to hear and see predators from afar, and to outrun and dodge them when they are near, may suffice. For such an animal, a bigger brain might just be a waste of valuable energy.

However, nature has undoubtedly experienced a widespread trend towards greater intelligence in many animals - a fact which makes clear that intelligence is a valuable asset in a diversity of lifestyles. The trend has also been an accelerating one, for several reasons.

• First is that the same quantity of brain growth - say 1 gram - requires more improbable genetic mutations for a small-brained creature than it does for a large-brained creature.

• Secondly, whereas certain attributes - for example speed - generally plateau at a certain level because of the rapidly increasing energy costs, the same may not always apply to brain size.

• Thirdly, beyond a certain level of intelligence, there may be 'positive feedback' between on the one hand, increases in brain size, and on the other, the growing range of behavioural options which is opened up by the burgeoning culture which accompanies high intelligence.

• Fourthly, as Stephen Jay Gould has argued, the long-term prospects of an ecological 'generalist' are better than those of 'specialists' (but only if the ecology tends to undergo sudden changes). In other words, when an ecological situation changes, a specialist is vulnerable because its survival strategies are outmoded; on the other hand, a generalist is more likely to have alternative strategies to fall back on. For example, a monkey can often survive pretty well if one food source is removed, because it has others and because it's clever enough to expand its operations. On the other hand, a koala is done for if you kill all the eucalyptus trees in its area - the leaves of that tree are its only food source.

The intelligent animal is, other things being equal, more likely to be a generalist, because when the going gets tough, it is more capable of learning, of remembering past strategies, and of innovation. For instance, there is a pride of lions in - South Africa's Kruger National Park - which specialises in killing and eating porcupines. Such novel strategies spring more readily from an intelligent mind than they do from genetic changes over generations (with the exception of very small and quickly-reproducing creatures such as bacteria). As Steven Pinker puts it, 'humans have the unfair advantage of attacking in this lifetime organisms that can beef up their defenses only in subsequent ones' (How the Mind Works, pg.190).

Have the costs of developing high intelligence been overstated? Our brains consume approximately 20% of the energy used by the body; so in order to earn its keep, the human brain must be responsible for increasing energy intake by at least a fifth. Clearly, the brain of homo sapiens is more than equal to the task; but this is not enough: the brains of all our evolutionary predecessors, many slightly brainier than the preceding one, would also have had to earn their keep. It has recently been suggested by DNA analysts that 65,000 years ago, our ancestors dwindled in number to a mere 10,000*. I am not aware of the exact circumstances under which this putative bottleneck occurred (Steven Pinker says that it may have been because of global cooling triggered by a massive volcanic explosion in Sumatra); but if it did occur, it seems that one must draw the conclusion that high intelligence is not always enough to make a species flourish. My own intuition is that intelligence is more valuable than is often made out; the flexibility, learning and innovation which it allows must in many circumstances 'earn their keep' in extra energy. However, most of my arguments here are theoretical, and I don't claim that they prove anything. But I do think it worthwhile to question the claims being made that human-level intelligence is a once-off fluke.

* Or that there was a series of less serious incidents which did reduce human numbers, but less dramatically.

A more constant source of hardship to plants and animals has (to state the obvious) been other plants and animals. The evolutionary change which is caused by such hardship has been described as an 'evolutionary arms race'. To paraphrase "Alice in Wonderland"'s Red Queen (I am not the first person to do this in an evolutionary context), you have to keep running to stay in the same place. Although competing species often stay in the same evolutionary place relative to each other, they do not stay in the same place in absolute terms; in fact, they can undergo accelerated evolutionary change, as advantageous mutations in the genome of one species must often be counteracted by mutations in the genome of its competitor.

Selection pressures can lead evolution in very odd directions. The most complex machine of which we know - the brain - has come up with some particularly interesting innovations to increase its efficiency. Among these are dreams.

THE PURPOSE OF DREAMS

"Evident it is, that horses, dogs, kine, oxen, sheepe, and goats, doe dreame. Whereupon it is credibly also thought that all living creatures that bring forth their young quicke and living, doe the same. As for those that lay egges, it is not so certain that they dreame; but it is that they do sleepe"

- Pliny ¹

What is the function of that odd phenomenon, dreaming? Does it actually have a function, or is it just a form of 'mental static'? I think it must help animals survive; dreaming would not have evolved if it had not inevitably had a positive impact on mental processes. Dreaming involves a higher metabolic rate than deep sleep does; evolution is too niggardly to allow so much energy to be frittered away pointlessly. In view of what we know of natural selection, and of the effects of REM sleep deprivation (REM or 'rapid eye movement' sleep takes place when we're dreaming), it seems highly likely that dreaming is crucial to our mental functioning.

So how might dreams have enabled our evolutionary predecessors to survive better?

Some scientists theorise that dreams consolidate learning and memory. Evidence? In one study, people taught a skill and then deprived of non-REM sleep were able to recount what they had learned; those deprived of non-REM sleep could not [National Institute of Neurological Disorders and Stroke, NIH]. Hennevin et al.

"consistently found that in the hours following training, animals spent increased time in [REM sleep] with respect both to their pre-training baseline level and to control animals exposed to the same training circumstances but [who failed to learn]. Slow-wave [non-dreaming] sleep duration was unchanged"¹.

They found a striking correlation between the increase in REM sleep and the degree to which the newly-learned tasks were remembered.

It should be borne in mind that REM sleep may not perform the same functions across species (and may carry out different functions within a single brain); there is at least one study whose results may challenge theories that learning and memory consolidation are the only functions of REM sleep. Jerry M. Siegel et al. of the Sepulveda Veterans' Affairs Medical Center, California, conclude from their studies that "cats, opossums, armadillos and other mammals not known for their intellectual achievements have far more REM sleep, whether calculated in hours per day or as a percentage of total sleep time, than humans" [Nature, 11^th August 1998¹].

A theory which could either supplement or supplant the learning/memory one is that (at least some) dreams are simulations designed to hone our survival skills without putting us through the dangers, failures and considerable energy expenditure that accompany make-or-break situations in the real world. While you're dreaming, the brain is still sending out instructions for how you should move and act; it's just that these messages are prevented from reaching their targets (muscles, legs, arms, etc.)*.

* except in conditions such as sleepwalking and REM sleep behaviour disorder. These behaviours differ from each other; sleepwalking (somnambulism) does not appear to take place during REM sleep. It should be noted that even non-REM sleep can contain elements of thought, although not with the same intensity. [The Oxford Companion to the Mind].

Whether or not current theories are entirely correct, they do have some plausible elements. But dreams have some aspects which, though readily accomodated within the theoretical framework, are nonetheless odd. For example, it is strange that, if the theories be true, learning and memory are reinforced by a process whose conscious manifestation - dreams - we can rarely recall.

I am also intrigued by the (less paradoxical) fact that dreams aren’t precise reruns of recent events. A couple of possible reasons for this occur to me.

The outside world does not impose sanity on a sleeping mind. In the outside world, events are always logical; but in the inside world, events do not have to mirror life’s logic. But we humans are superb at constructing and remaking highly convincing tales; whilst these are generally more dramatic than our lives, they are nonetheless more coherent than dreams. Could this be because in sleep, the part of our brain which arranges narratives is dormant, and the information and memories are cut adrift from its logical hold? Nature rarely uses what it doesn’t need. Even if I'm right, why don’t we just have a jumbled rehash of recent events? Could dreams be arranging memories within a wider context, so that useful information need not only be triggered by the kind of circumstances which first created the memories? These aren't rhetorical questions; I genuinely don't have much of a clue.

And why are dreams so emotionally powerful? Our dream lives are - by and large - far more dramatic than our waking existence. What themes are more common in dreams than in life? Here are some of them: fear; fire; snakes; being naked and embarrassed in front of groups of people; death; falling; and being attacked¹. More everyday topics include: money; swimming; romance and sex; school; and eating*. This list strikes me as a compromise between modern themes and the motifs which preoccupied our distant ancestors, who were more at risk from dangerous animals, murderous humans, fire and famine. Despite their ramshackle logic, dreams may at times be more accurate than our waking thoughts at giving us a picture of what evolution has equipped our minds to be concerned with.

In similar vein, I find it interesting that no matter how far modernity takes us from the ancestral lifestyle, we always strive to recreate aspects of it via entertainment. Even where these ancient scenarios are unpleasant, many of us feel compelled to relive the emotions they aroused! Here, the obvious example is horror movies; although they scare the crap out of me, I love watching a good one (for example, ‘The Shining’ by Stanley Kubrick). Perhaps - and this is sheer speculation - evolution’s ‘thinking’ here is "know thine enemy [or ally, sexual rival, food source, etc.]". Sports, dreams, horror movies and computer games may, like playing, be evolution’s way of preparing us for challenges - many of which will never come. Fleeing terrifying beasts, fighting, and hunting are part of the human mind*; if we don't entertain ourselves with activities designed to mimic them, our lives can seem rather empty.

* yes, I'm talking more about men than women

- Oliver Goldsmith

Consciousness:

The two most baffling things I can think of are

• that anything exists, and
• that consciousness exists.

Surprisingly often, philosophers and others have mistaken other things for consciousness: for example, self-awareness, 'theory of mind' (i.e. constructing theories about other creatures' minds, thoughts and motives, rather than just acting instinctively towards them), and attention. Although these may often be associated with consciousness, you can trust me when I say they are not the same thing. Think about it: you can construct a tiny robot that pays attention to itself, constructs simple hypotheses about others, goes to sleep sometimes and pays attention at others, and has no consciousness whatsoever. It acts, but doesn't experience (that statement is unscientific, because I can't prove that such a robot isn't conscious. I can't prove that I'm conscious. But I'm pretty sure I'm right).

The difficulty in understanding how consciousness arises lies in the fact that it is the result of physical processes in the brain (interacting with other parts of the brain and with the outside world) which are enormously complex, and very difficult to monitor and to connect to specific thoughts and images, let alone to such an ill-understood phenomenon as consciousness*. The mind is made up of rapidly changing alliances of chemical and electrical phenomena among the billions of cells which constitute the brain. It may be a long time before we - or perhaps our robotic successors - can catch the leaping and re-forming patterns of consciousness in the brain and say with confidence that we know why a certain configuration of cells, chemicals etc. in a certain part or parts of the brain produces consciousness.

* It is often noted that evolution moves blindly towards the best nearby solution; it does not work towards any ultimate goal. It will go up the nearest road without realising it's a cul-de-sac. This is one reason why most life forms are unthinking automata, most of whose activity is very directly aimed towards the replication of the genes which they contain.

The Brain:

Even 'mundane' tasks involve astonishing feats of calculation: as I write this, fully-formed sentences 'appear' in my mind, are broken down to their constituent letters, each in the correct order, and tapped out to appear on the computer screen, using the correct combination of the vast number of alternative actions which can be performed by brain activity, bodily nerve impulses, the use of 10 digits and a large number of squares and combinations of squares on the keyboard. This sort of (limited) analysis can be applied to any of the activities which we and other animals with decent-sized brains engage in. As I go about my life, though, I'm only conscious of a tiny subsection of these activities; as evolutionary psychologists John Tooby and Leda Cosmides write, "the only things you become aware of are a few high level conclusions passed on by thousands and thousands of specialised mechanisms". We are all being served by enormously subtle and powerful calculating machines of whose workings we have little inkling.