- Stephen Hawking
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It is amazing that out of the countless trillions of ways molecules can be arranged, only a few million ways result in things that can reproduce themselves. The biologist E.O. Wilson estimates there are about 13 million species, broken down as follows:
Insects 9 million
Bacteria 1 million
Fungi 1 million
Viruses 0.3 million
Algae 0.3 million
Worms 0.3 million
Plants 0.2 million
Protozoa 0.2 million
Echinoderms 0.2 million
Mollusks 0.2 million
Crustaceans 0.2 million
Fish 30 thousand
Reptiles 10 thousand
Birds 10 thousand
Amphibians 5 thousand
Mammals 5 thousand
It has been estimated that since the Pre-Cambrian Explosion 540 million years ago, during which the predecessors of most of these species arose, upwards of 90% of all species are extinguished each 100 million years due to environmental catastrophes. Hence, even counting the ways life might have been organized in the distant past, not more than a few hundreds of millions of molecular patterns have worked. In comparison, a practically infinite number of molecular patterns are possible given the dozens of atomic building blocks nature has to work with and the astronomical number of possibilities for stringing these atoms together in three-dimensional space.
Far, far less than one in a thousand molecular patterns will result in something that lives. It is not just about the magic of the DNA and RNA molecules. Most forms of even those molecules would not result in organisms that felt obligated to eat, excrete and respond to stimuli. Only the rare special cases of viable DNA and RNA molecules can do that. Very precise nucleotide sequences are needed to organize random atoms into protein building blocks that work together so symphonically that a reproductive being results. Life is a miracle because it is so unlikely.
Yet, we are inundated with life. Our skins crawl with bacteria, and our planet teams with skins. This is because life works very well. No matter how rare it is in theory, once it occurs it multiplies, for that is what life does. Rocks crumble and aggregate, but lives copy and proliferate. Most importantly, life also mutates. This is because the process of copying DNA is imperfect. Mutations result in diversity among life forms, and this diversity is crucial to life’s success. Diversity enables life to keep trying out new forms of molecular organization. Forms that work well spread and ones that don’t become rare or extinct.
The lesson of life is just this simple: no matter how unlikely something is in the first place, once it occurs it will become prevalent in those niches in which it continues reproducing versions of itself.
Life owes its improbable existence to an exceedingly rare kind of code. This life-code does two things unique to life. First, it enables self-replicating order to be structured out of disorder. Second, it enables that order to be maintained (for a while) against all the forces that make things fall apart. Wow yourself with this: life-codes are merely a mathematical sequence, like a formula, that shazam-like transforms randomness into purpose and entropy into organization. Life-codes are a real-world Harry Potter incantation, expressed in numerical silence. Any string of numbers that can God-like summon beings out of inanimate dust is as amazing as this universe gets.
Mathematics is invisible. We see its shadow when it gets expressed in something tangible. DNA is a molecule of life because it expresses a mathematical code that organizes viable patterns of molecules out of the inert chemical soup surrounding us. The patterns are viable because they self-replicate and they maintain their order, for a time, against Nature’s forces of disorder. The patterns are visible as nucleotide sequences, but their capabilities are based upon the arithmetic of the sequences – the specific numbers of A, T, G and C molecules that are required to direct the assembly of a specific protein needed to maintain a life process.
From the mathematical underpinning of biochemistry we can state an elegant definition of life: the expression of a code that enables self-replication and maintenance against disorder. Rocks are not alive because they are not the expression of a code. But the algae that covers a rock is. Microsoft Word is not alive because it doesn’t self-replicate (humans copy it). But software that could self-replicate and maintain itself against degradation would seem to be as alive as algae.
The genius of Darwin was to see a continuous chain of life in an immense scattering of broken shards of separated links. We can build on Darwin by presenting a continuous chain of life-codes in what otherwise looks like disparate phenomena. Specifically, RNA, DNA and software life- codes are links in an evolutionary chain. It is the chain of mathematical sequences capable of organizing self-replicating and self-maintaining entities out of inert building blocks. This view is consistent with the so-called “disposable soma” theory of evolution, “soma” being the Greek word for body. The theory says that bodies are DNA’s way of making more DNA. I’m taking the theory one level higher: somas are math’s way of making new self-replicating codes.
Nature surprises us with new life-codes just as she surprises us with new variations on existing life-codes. Nature will select new life-codes that are superior self-replicators in their niche just as she selects the best replicating variations on existing life-codes. Life-codes that give rise to many adaptable variations will become more dominant, just as phyla that give rise to many adaptable species become more prevalent. It is simply a step-up of scale to understand that evolution operates on types of life-codes as well as on the offspring of life-codes. DNA, as a type of life-code, is itself subject to a struggle for survival just as are the millions of species that use it as their code for organizing order out of raw nature. It is exciting to be alive at the time that new kinds of life-code, based in software rather than molecules, make their initial appearance.
We Bring Improbable Things to Life
The numbers of ways to write software are as unlimited as the ways to string molecules together. It might seem as unlikely for software to become alive as it was for molecules to become alive. Yet while it took eons for earth’s first molecules to self-replicate, people have already hit upon certain strings of software code that reproduces itself. We call them software viruses. People have also organized lines of code into sequences that respond to stimuli. These programs are familiar to any gamester or avatar user. Humans endlessly mutate (“hack”) software the way cosmic rays and random chemistry mutate our genetic codes. A good argument can be made that these hacks have already produced software with most if not all the qualities of life.
Just like life, software is organized, and exchanges energy with the environment. It takes in electricity and sheds heat via its hardware, much as a genetic code takes in nutrients and sheds waste via its body. As with living molecules, living software can reproduce, respond to stimuli, develop and adapt. Programs are written that go out onto the web, find compatible freeware, cut and paste it into the original code and continue developing. Humans and other life forms develop analogously: we go out into our natural environment, incorporate food and compatible experiences.
There are of course many differences between organic life and software that has characteristics of life. But the simple lesson of life remains the same: No matter how unlikely living software is, once it occurs it will become prevalent in its niche if it can continue reproducing itself.
Now, these are undeniable facts: there is universal fascination with software (e.g. applications), software has a gigantic stake in the economy (e.g. chips) and the energies of hackers worldwide are mind-boggling (e.g. web apps). These forces are as prolific in producing living software prototypes as Mother Nature was in producing living RNA/DNA prototypes. Organic life clicked “on” then, and cybernetic life is clicking “on” now. Improbability becomes inevitability when numbers get large. There are a very large number of people working on imbuing software with the characteristics of life.
The differences between organic and cybernetic life are less important that their similarities. Both are mathematical codes that organize a compatible domain to perform functions that must ultimately result in reproduction. For organic life, the code is written in molecules and the domain is the natural world. For cybernetic life the code is written in voltage potentials and the domain is the IT world. We call organic life biology. It seems fitting to call cybernetic life vitology .
In biology the mathematically coded nucleotides organize nearby atoms into ever-larger molecules. These molecules, such as proteins, do life’s work of reproducing by bulking up and (if sufficiently evolved) trying to stay safe. In vitology the mathematically coded voltage levels organize nearby sub-routines into ever-larger programs. These programs do life’s work of reproducing by occupying more firmware and (if sufficiently evolved) trying to stay safe.
It is interesting to recall that molecules also depend upon electron-based voltage levels to stay connected. Atoms bind into molecules via either covalent or ionic electron coupling. Hence, at the most general level, vitology is a life-code that requires only electrons, while biology is a life- code that requires atomic nuclei as well as electrons. The electron-based life-codes of vitology must be seated in compatible computer hardware, while the atom-based life-codes of biology must be seated in a compatible nutrient milieu. The main point is that biology and vitology are each abstract mathematical codes that spell out the path to self-replication in organic and IT environments, respectively. Thus, stripped to its essence, all life is but the expression of self-replicating codes.
What Is Life?
Many experts have tried to lasso the definition of life. They often disagree: some emphasize biology, others physics, some requirements are Darwinian, others spiritual. They are all talking about pretty much the same things we think of as being alive – plants, animals, and microbes. The problem is that none of the definitions are consistent and complete to everyone’s satisfaction. Some definitions exclude sterile worker bees, while others exclude flu viruses. Every boundary falters at its edge. So, why bother trying to come up with a one-size-fits-all definition of life?
There are no philosophically compelling reasons to define life. The reasons are all utilitarian. Humans are passionate about categorizing things, for much the same reason they like to build fences. It stakes out a territory that can be used for one’s benefit. Defining organic life as biology empowers biologists to be the source of expertise on the organic aspects of life.
I’ve just suggested a new kind of life, vitology, because software is arising that has the functions of life, but not the substrate of biology. As this living software evolves some versions will unambiguously seem to be alive, and soon thereafter other versions will aggressively claim to be sentient and conscious. All life forms try out, via mutation, different shapes and behaviors – software won’t be any different. If these sentience or consciousness claims are helpful to survival, we can expect seeing more software adopt the same position. It is not necessary to posit that the vitological software “wants” to survive for this to occur, any more than it is necessary to posit that bacteria “want” to survive. It is simply that things that do survive become more prevalent and things that don’t tend to disappear.
We can either deny vitological claims of consciousness, or broaden membership in the huge family of life. To do the former is to incite a long, unpleasant conflict. Think slavery and its disavowal of African humanity. To do the latter requires more than the biologist’s expertise. Hence, avoiding a conflict amongst substrates – flesh versus firmware, wet versus dry, natural versus artificial, DNA coded versus digitally coded – this is a reason to (re)define life.
Biologists purport to be the experts on defining life. They believe it is something that is (1) organized, (2) exchanges matter and energy with the environment, (3) reproduces, (4) responds to stimuli, (5) develops and (6) adapts. If something meets these criteria, then biologists will study it.
Physicists have also tried to define life. Physicists are the experts on physical reality, of which life is certainly a part. To these scientists, life is something that – for a while -- runs counter to the Second Law of Thermodynamics. This law says that everything in the universe is becoming more dis-ordered and random. Since life actually builds and maintains order in a defined area, it alone seems to defy physics and thus gives it a unique defining characteristic. In the words of Erwin Schrödinger:
“A living organism [like everything else in the universe] continually increases its entropy – or, as you may say, produces positive entropy – and thus tends to approach the dangerous state of maximum entropy [thermodynamic equilibrium, when nothing moves], which is death. It can only keep aloof from it, i.e., alive, by drawing from its environment negative entropy [which means order or structured things]….”
Physicists will concede, however, that their definition also has exceptions. Nobody feels that stars or galaxies are alive, and yet these objects build and maintain order at the expense of the cosmic things they suck up. Many of these environmental intakes would qualify as “negative entropy”, or ordered things, such as when a galaxy grows by swallowing another galaxy. The growth of a star by accretion of atoms blasted into space by supernovae is not so different in terms of Schrödinger’s definition than the growth of bacteria by assimilation of terrestrial carbon, hydrogen, oxygen and nitrogen.
We’ve sent several spacecraft to the surface of Mars with sensitive equipment to detect whether or not there were chemical signs of life in the Martian soil. The results were ambiguous. Even the top exo-biologists could not agree on whether the chemical signs we measured in the Martian soil were signs of life.
It is tough, if not impossible, to come up with a consistent and complete definition of life. For most people life is something “natural” that “acts alive.” We think something “acts alive” if it moves under its own power, like a stick that suddenly makes us jump because it turns out to be one of the three thousand species of insectoid walking sticks (Phasmatodea). We think something is “natural” if it is not man-made at all, or man-made only from living components. For example, a new breed of dog may be man-made, but we don’t doubt the Labradoodles are alive since they are made by hybridizing labradors and poodles. Similarly, baby humans are man-and-woman-made, but from things that act alive, like sperm and egg cells. On the other hand, the best man-made robot came from things like silicon and rubber that are not considered living. Hence, we don’t think robots are alive.
The Martian experience highlights a problem with another possible criteria for defining life: does it possess DNA or RNA? These are the molecular codes for making the forms and functions of everything we think of as living. Scientists feel that we can’t assume life evolved these same molecular codes off the earth. Furthermore, there are things such as viruses that possess RNA and yet are not admitted into the textbooks of life. This is because they are inert unless and until they are brought inside a cell.
The peculiarity of RNA and DNA could be circumvented by defining life as “anything that operates in a compatible environment pursuant to a code that is subject to natural selection.” Natural selection requires a code to replicate with some incidence of mutation (error) so that alternate versions of a life form can have a differential chance to thrive in new or changing environments. Under this definition, everything that biologists call life would be life because all those species have a code subject to natural selection, i.e., DNA or RNA. In addition, some things that biologists do not call life, such as viruses, would be considered alive because their code is subject to natural selection when it is in a compatible environment (a cell). On the other hand, things that are not called life, such as crystal rocks or neutron stars, are not alive because they are not operating in accordance with a replicable code.
An important feature of this all-encompassing definition is that it would include software viruses and other programs that either propagate, or disappear, in accordance with their environmental compatibility. In this case, the environment is information technology such as hardware, firmware and software.
A software program is a code, much like DNA or RNA. It instructs other software to do things as DNA instructs other molecules to do things. If software codes can make many copies of themselves, they will become prevalent, just as is the case for DNA-based beings. If software codes fail to significantly self-replicate, they will become “missing links”, disappearing from reality over time. If software codes mutate, such as by inaccurate copying, they will usually not function at all, or not function differently. Similarly, most DNA mutations are either benign or fatal. Sometimes, however, a software mutation could be beneficial in its original or in a new computing environment. In such rare cases, that software mutation would become the preferred form of the program, and would proliferate. Again, it is the same situation with DNA. It is thanks to millions of rare beneficial DNA mutations out of a countless greater number of dysfunctional ones that plants and animals arose from simple cells.
Schrödinger recognized the key role of DNA/RNA-based chromosomes in providing the source of order by which living things uniquely defy the Second Law of Thermodynamics:
“An organism’s astonishing gift of concentrating a ‘stream of order’ on itself and thus escaping the decay into atomic chaos – of ‘drinking orderliness’ from a suitable environment – seems to be connected with the presence of the ‘aperiodic solids’, the chromosome molecules, which doubtless represent the highest degree of well-ordered atomic association we know of – much higher than the ordinary periodic crystal – in virtue of the individual code every atom and every radical is playing here.”
The order of the chromosome that Schrödinger sees as behind the uniqueness of life is not different in function from order of self-replicating, self-maintaining software code. Consequently, life is that which has an order-constructing code enabling the entity to maintain itself against disorder. The requirement for self-replication, or Darwinian selection, simply extends this code-based definition of life into multiple generations. In essence, the living “entity” that is doing battle against disorder becomes the species rather than a member of the species. Humans, for example, are alive because they are members of a species that have a code (DNA) enabling order to be fabricated out of the environment for the benefit of maintaining the species’ battle against disorder (staying alive long enough to create subsequent generations that do the same thing).
Combining these considerations, we can answer the question of what is life as follows:
Life is anything that creates order in a compatible environment pursuant to a Darwinian code. If the code is Darwinian (subject to natural selection) then it must be self-replicating and it must structure a host (Schrödinger’s ‘negative entropy’) for itself that lasts long enough to self-replicate. As Joel Garreau has observed, chickens are the egg’s tool to make more eggs.
Biology versus Vitology: A Sixth Kingdom, Fourth Domain or Second Realm
Our consistent and complete definition of life will not satisfy everyone. Biologists will not see their commonality with software engineers, even though the simplest and most elegant definition of life includes both their subject matter. To solve this problem it might be necessary to admit that there are two different kinds – or realms -- of life: biological life, and vitological life.
Biological life is anything that operates in a compatible environment pursuant to a DNA or RNA code. Indeed, the current taxonomical division of life into three domains (archaea, bacteria and eukaryota) is mostly based upon systematic differences in these codes. (Despite these systematic differences, the most advanced eukaryota, mammals, have one-third of their genome in common with the most primitive domain, archaea.) Previously, biological life was sub-divided into five kingdoms (monerans, protists, eukaryotes, fungi and animals) based on the structure and function of each group’s cells.
If software-based forms of life were to be accommodated within the current domain-based vision of life, the resulting phylogenetic tree might look something like the following figure, created by biologist and cyberlife pioneer Nick Mayer. A fourth domain, “digitaea” would accompany archaea, bacteria and eukaryota. Note that digitaea branches off of animals and hominids just as those groupings branched off of plants and fungi long ago. Three species of digitaea are suggested: stemeids that are mindclone continuations of hominids, nanoids that are new life forms assembled from self-replicating nanotechnology, and ethereates for new purely software-beings, lacking any physical instantiation.
In fact, it is awkward to categorize vitology using biology’s domains and kingdoms since both DNA and cell structure is irrelevant to purely code-based life forms. Vitological life is anything that operates in a compatible environment pursuant to an electronic code that is subject to natural selection. The limitations to Darwinian and electronic codes is to emphasize that we are talking about life-like beings – things that are part of a class that can self-replicate, compete for resources and survive – and to codes that are written in 0 and 1 energy states in pieces of technology.
Vitological and biological life are developing radically differently. Vitological life is in many respects more primitive than prokaryotic cells, which lack even a nucleus. A software virus is about as functional as a biological virus. On the other hand, there are software modules such as web crawlers and navigation routines that can outsmart the cleverest animals on the planet. These modules are not alive, for they lack any drive to self-replicate, but they could be cobbled into a larger program that did meet most or all of the expectations of life. Most remarkable is that all these jigsaw pieces of vitological life popped into being within a few decades.
Meanwhile, biological life continues to change so slowly that we marvel at the genius of a Darwin to see the continuity amidst all the extinct pieces. Mutations arise, and specie dominance changes, especially amongst bacteria. But everything is incremental. There are no fundamental new biological capabilities popping into being analogous to navigational guidance software.
Vitology benefits from Lamarckism, the ability of offspring to inherit characteristics acquired during the life of its parents, whereas biology generally does not. Acquired characteristics cannot be biologically inherited, but they can be (and usually would be) inherited by copying software forms of life. This difference greatly accelerates the evolution of vitological life. It is also perhaps the clearest way to demarcate the vitological from the biological realms of life.
There is no a priori reason why living things should not inherit in a Lamarckian manner, but it is a fact that biological beings generally do not while vitological beings generally will. Giraffes are not able to rewrite their DNA code to incorporate useful characteristics they acquired, such as a more muscular neck, but must instead await random genetic mutations that lengthen the neck. A cyber-Giraffe, however, would necessarily have changed its code to cyber-muscularize its neck, and would thus necessarily pass onto its cyber-offspring the lengthened neck.
Vitology is proceeding as if the brain, the eye, the limbs, the vital organs and the basic cell all developed at once, but as separate entities. None really looked alive except maybe the basic cell – the rest were just really cool tools without a future or a past. A Darwin could see the inevitability of software hacks that would stitch the entities together into a piece of life par excellence. He would realize that once such hacks occurred, the resultant being would self-replicate like crazy. That is what life’s program would tell it to do. It would have the smarts to carry out that program despite obstacles and enemies.
It is obvious that vitology is developing millions of times faster than biology. Vitology is parallel processing in decades what biology serially processed over epochs. This difference of phylogeny, their unique domains of competence and their customized tools for achieving reproduction are what makes it unobvious that they are just two different approaches to life. But squint at that mutating self-replicating code at the core of it all, and at the common life-like functions they share, and it becomes clear that strings of digits spell life just as well as can strings of molecules.
Mindclones are alive, just not the same kind of life that we are accustomed to. They are functionally alive, albeit with a different structure and substance than has ever existed before. Yet, that is the story of life. Before there were nucleated cells, eukaryotes (of which we are comprised), such things had never been seen before – not for nearly two billion years. That is time duration that bacterium had an exclusive claim to life on earth. Before there were multicellular creatures there were only single cell creatures – from their perspective, the first slime molds were not so much a life form but a community of single cell creatures. And so the story goes, down through the descent of man. We must judge life based upon whether it streams order upon itself – self-replicates pursuant to a Darwinian code and maintains itself against the tendency to dissemble – and not get picky over what it looks like or what flavor of Darwinian code it uses. Using this objective yardstick, vitology will be alive.
Mindclones, sitting at the apex of vitology, will feel as full of life as we do from our perch atop the summit of biology. Aware of themselves, with the emotions, autonomy and concerns of their forbearers, mindclone consciousness will bubble as frothily alive as does ours.