Note this is the version
submitted to the editors in December 2007. It may have been edited
before publication.
For a lecture on this theme see
TED.
Cultural
evolution is a dangerous child for any species to let loose on
its world. And the parent species, whatever it is like and
wherever it arises, will have no insight into what it has done
until its offspring is already grown and making its way in the
world. By then it is too late to take it back. So I shall call
this motherly species ‘Pandoran’, after the mythical first Greek
woman whose box released all the evils of mankind. We humans are
Earth’s Pandorans, and have let loose cultural evolution, but on
other planets quite different creatures might be playing this
role.
Opening such a
box of tricks can even be lethal, and I suspect that there are
several danger points. The first critical step occurs when one
species becomes capable of behavioural imitation, or of some
other process that makes copying with variation and selection
possible. This creates a new replicator, making the evolution of
culture inevitable. This is the first danger point, because the
newly created culture – the spreading of copied behaviours and
the competition to mix, match and make more – can get out of
hand. Some of the behaviours may be so extravagant, or
expensive, or dangerous, that they kill off their Pandorans and
so obliterate themselves as well. This kind of waste is all part
of how evolution works. Indeed natural selection might be called
“design by death” because of all the billions of creations that
have to die in spawning innovation and success for a few.
If this first
danger point is passed, the Pandorans and their newly spawned
culture may begin to adapt to each other, and coevolve towards a
more symbiotic relationship, as diseases and their hosts
sometimes do. If this succeeds, the result may be a stable
mutualism that lasts indefinitely. Alternatively, with enough
time, and under the right conditions, another step might be
taken. That is, new mechanisms for copying, varying and
selecting information could evolve outside of the Pandorans
themselves, leading to a second danger point. For example, here
on earth, humans invented printing, sound recording and
photography, vast communication networks, broadcasting and the
Internet. These are all methods of selective copying which means
a new evolutionary step, and this creates a second danger point.
As the copying increases, the thirst for innovation that’s
unleashed can be a drain not only on the Pandorans who started
it but on their whole environment as well. This is what has
happened here on earth, with the consequent overpopulation and
technological explosion threatening the health and climate of
the entire planet.
This danger
point could also be safely passed, or it might prove fatal. We
don’t yet know what the outcome will be here on earth; it might
go either way. However, our sample of one planet does at least
allow us to think about the general picture and speculate about
what might happen on other planets elsewhere in the cosmos.
I like to
imagine a vast universe containing many planets which have
conditions suitable for life to evolve. On some of those planets
a species evolves that is capable of copying what others do, so
unleashing this second evolutionary process. Among those
planets, some survive the danger point and some do not, with the
successful ones going on to spawn further evolutionary steps and
face further danger points. On this picture, what should we
expect to see around us? I would like to explore what might be
out there on the basis of this memetic way of thinking about
cultural evolution. I shall first explain a little about memes,
meme theory and the importance of replicators, and then consider
some of the possible fates of planets that give birth to
multiple replicators as ours has done.
The science of
memes
Memetics is
rooted in universal Darwinism; that is the idea that natural
selection is a general process of which earthly biology is just
one example.
Working from
his detailed observations of living things, Darwin saw what very
few people had ever seen before, even though the process is
always staring us right in the face. That is, if creatures vary,
and if they have to compete for resources so that most of the
variants die, and if the successful variants pass on to their
offspring whatever it is that helped them survive, then the
offspring must be better adapted to the environment in which all
this happened than their parents were. Repeat that cycle of
copying, varying and selecting, and design must appear out of
nowhere.
My favourite
word in that description is “must”. This “must” is what makes
Darwin’s insight the most beautiful in all of science. You take
a simple three step algorithm and find that the emergence of
design for function is inevitable. Dan Dennett calls it “a
scheme for creating Design out of Chaos without the aid of Mind”
(Dennett 1995 p 50). This is “Darwin’s Dangerous Idea” that the
algorithmic level is the level that best accounts for the
wonders of nature; that all the fantastic and beautiful
creatures in the world are produced by lots and lots of tiny
steps in a mindless and mechanical algorithm.
The whole
process can look like magic – like getting something for nothing
– but it isn’t. It is not possible to get matter out of nowhere,
but it is possible to get information, or new patterns of
matter, apparently out of nowhere by making copies. If the
copies vary slightly and not all the copies survive, then the
survivors must have something that helped them win the
competition – using Darwin’s term they are more “fit”; they make
a better fit to their environment. Then they pass on this
advantage to the next generation of copies. And so it goes on.
This is the
fundamental idea that Richard Dawkins explained in his 1976 book
The Selfish Gene. He emphasised the importance of thinking about
evolution in terms of information rather than squishy living
creatures, and he called the information that is copied the
replicator. In fact “replicator” is not a very good name,
implying that it is the thing that does the replicating rather
than being the thing that is replicated (perhaps ‘replicatee’
would be better) but ‘replicator’ is what it is called and I
will stick with that here; the concept is more important than
the name.
For Dawkins it
was a general law, “the law that all life evolves by the
differential survival of replicating entities.” (1989 p 192); a
“view of life …that applies to living things everywhere in the
universe. The fundamental unit, the prime mover of all life, is
the replicator.” (1989 p 264)”. With this view he wanted “to
claim almost limitless power for slightly inaccurate
self-replicating entities, once they arise anywhere in the
universe.” (1989 p 322).
From the
perspective of this general law, genes are only one example of a
replicator. So we might expect them to show both characteristics
that are true of all replicators everywhere in the universe, and
features that depend on the idiosyncrasies of evolution here on
earth. Dawkins wanted to explore the general principles as well
as the specifics. Indeed he became quite frustrated with the way
his colleagues tended to think about evolution as though it were
inevitably and always a matter of genes. So at the end of the
book he asked his now famous question “do we have to go to
distant worlds to find other kinds of replicator and other,
consequent, kinds of evolution?” (1989 p 192). His answer was,
of course, no. Staring us in the face, “still drifting clumsily
about in its primeval soup” (1989 p 192), is a new replicator;
tunes, ideas, catch-phrases, fashions, and ways of making things
are all spread from person to person by imitation. They vary and
they are selected. These are the new replicators; the memes.
There is
nothing mythical or hypothetical about memes, and this point is
frequently misunderstood. Some people seem to imagine that memes
are some kind of abstract entity that might, or might not, live
inside brains; or that might, or might not, really exist (Aunger
2000). This is to miss the point that everything we copy in
culture is a meme, by definition. So the words I am writing now,
the picture on the cover of this book, the practice of making
books like this, and making paper and ink and glue this way, are
all memes. As Dennett (2006) points out, there is nothing
mythical about words printed on a page, or even spoken words or
recorded and broadcast words. Indeed Darwin referred to “The
survival or preservation of certain favoured words in the
struggle for existence” as a kind of natural selection (Darwin
1871, p 61). There is nothing hypothetical about kids listening
to i-PODs, wearing pre-torn jeans, or putting pieces of metal
through their ears and noses after seeing others do the same.
There is no question about the existence of financial
institutions, money, railways, bicycles, telephones, furniture,
skyscrapers, holiday brochures, football, or the days of the
week. They are all information; they are all encoded in some
kind of matter and energy, and they can all be copied or not. So
think of memes this way. Their core definition is “that which is
imitated” or that which is copied. They are all around us.
There is no
question, then, that memes exist, for unless you deny that
anything is ever copied from person to person, they must. The
real question is whether thinking about culture in terms of
replicators and memes is useful or not (Laland and Odling-Smee
2000). I am convinced that it is, or at least that it can be.
Already, considerable progress has been made in identifying the
problems, clarifying the issues, and beginning some empirical
investigations. For example, there have been constructive
arguments about how to define memes (Aunger 2000, Blackmore
2001), whether they should be thought of as units or not
(Sperber 2006, Wimsatt 1999) and whether they should be
considered as inside or outside of human brains (Aunger 2000,
Benzon 1996, Distin 2005). Particularly interesting areas of
debate concern the extent to which behaviours are reconstructed
rather than imitated (Jablonka and Lamb 2005, Sperber 2006) and
whether memes are truly replicators or not (Blackmore 2001,
Richerson and Boyd 2005). Then there are empirical
investigations of, for example, replicating text (Pocklington
and Best 1997) and memes in translation (Wright 2000),
applications in sociology (Runciman 1998) and musicology (Jan
2007), and attempts to simulate and model memetic processes
(Bull et al 2000, Higgs 2000, Kendall and Laland 2000).
These are all
promising signs but it remains true to say that there is
currently no thriving science of memetics. It is, at best, a
tiny area with a few enthusiastic proponents. The reasons for
this are not clear. Some people seem simply to be afraid of the
whole idea of memes. This baffles me. When I gave my first ever
lecture on memes at the London School of Economics in 1996, I
mentioned that the word “meme” is often printed with scare
quotes, and that I had even seen lecturers putting up their
hands up round their ears in stylised scare quote fashion when
daring to mouth the word “meme”. More than a decade later I am
sorry to find that I am still seeing this bizarre behaviour.
Why? Is memetics really so scary? Possibly it is. Among the
ideas that upset people are that all ‘our’ ideas are
recombinations and adaptations of other people’s, that all
creativity comes from the evolutionary algorithm and not from
the magic of human consciousness (Blackmore 2007a, Chater 2005),
that our inner conscious selves may be memeplexes created by and
for the memes (Blackmore 1999), that free will is an illusion,
that modern computing technology is creating itself using us,
and that the process of memetic evolution is not under our
control (Blackmore 1999, Dennett 1995). These implications may
be scary, but it is far from certain that they do all follow
from a memetic view of evolution. In any case, being frightening
is not a good test of the truth or falsity of a theory.
Among other
reasons, some social scientists brand all evolutionary
approaches to their subject “reductionist”, and reject memetics
along with sociobiology and evolutionary psychology (Bloch 2000)
while some biologists want to keep Darwinism exclusively for
their own field and so reject its application to culture (Rose
and Rose 2000).
More
interesting here are those who accept that culture evolves but
still reject memetics. This may be either because they reject
the whole idea of replicators as the driving force in evolution,
or because they deny that memes are replicators. Wilson famously
argued that “genetic natural selection operates in such a way as
to keep culture on a leash.” (Lumsden and Wilson 1981 p 13). On
his theory and related theories of gene-culture coevolution, the
cultural variants (culturgens) are not independent evolving
entities but are part of the human phenotype and are an
adaptation that benefits human genes.
Branching out
from purely genetic evolution, Jablonka and Lamb (2005) explore
epigenetic and other evolutionary systems, but they do not
accept that “the dreaded memes” (p 224) are replicators, and
claim memetics is “seductively simple” but flawed (p 208).
Richerson and Boyd (2005), whose theory of cultural evolution is
arguably closest to memetics, do sometimes use the term ‘meme’
but they clearly state that “cultural variants are not
replicators”: “Culture is on a leash, all right”, even if the
dog on the end is big and clever, and “Culture is an
adaptation”. In other words, culture was adaptive for human
genes, it evolved for that reason, and it has persisted for that
reason – in spite of including some maladaptive elements. In
this respect they still illustrate Dawkins’ complaint about his
1970s colleagues that “In the last analysis they wish always to
go back to ‘biological advantage’.” (Dawkins 1976, p 193).
This reveals
the fundamental difference between all other theories of
gene-culture coevolution and memetics: for the former the final
arbiter is genetic advantage so that culture must always remain
on its leash, even if the leash sometimes gets very loose; for
memetics both genes and memes have replicator power and can
drive change and creativity. For other theories cultural traits
are an aspect of the human phenotype, but for memetics they are
living things in their own right.
These include a
vast range of memeplexes (co-adapted complexes of memes) that
are copied, stored and propagated by their human hosts, using a
wide variety of adaptations. All these, according to Humphrey,
“should be regarded as living structures, not just
metaphorically but technically.” (Dawkins 1989 p 192).
Some survive
predominantly because they are useful to their hosts (e.g.
effective financial institutions, scientific theories, or useful
technologies); others depend on fulfilling human desires and
preferences (e.g. the arts, music, and literature); and still
others are positively harmful, tricking their hosts into
propagating them. We humans are selective imitation devices
(Blackmore 2001); we try to select only the useful or valuable
memes but are inevitably tricked by some of the rest.
Popular
examples of the tricksters are informational viruses, such as
chain letters, email viruses and pyramid schemes. These reveal
the classic viral structure; an instruction to copy the whole
memeplex, backed up with threats and promises to ensure
compliance. Dawkins (1993) pointed out that the major religions
of the world have just this structure. Billions of people all
over the world are infected with a religion at an early age when
they have little memetic immunity, usually by their own parents
whom they love and trust. They then spend the rest of their
lives paying the price of adherence to false beliefs, and in
turn infect others. Thus we can see the whole history of
religions as an evolutionary competition for the replication of
information. What matters here is not specifically whether the
ideas are true, or whether believing them benefits their
carriers (although both of these may play a role), but whether
the religion can successfully get itself stored and replicated
using humans as its meme machines. The winners are those that
outdo the competition by developing adaptations such as
enjoyable rituals, memorable stories, glorious art and music,
explanations for life’s mysteries (whether true or not), or
nasty meme tricks such as threats of hell, and death to the
infidel. The religions we see surviving around us today are the
few big winners in that long and mindless competition to infect
human minds.
There have been
ferocious debates about this way of looking at religions, with
opponents arguing that God is not a virus (Bowker 1995, McGrath
2007), evidence accumulating that religions do not improve
societies’ health (Paul 2005) and arguments that faith itself is
harmful (Dennett 2006, Harris 2006). Sadly there has been little
in the way of meme-based empirical studies of religions and
belief, which is badly needed if memetics is to thrive.
The value of
memetics may also be judged by its theoretical contribution to
understanding human evolution here on earth, and the reasons why
humans alone have acquired complex and evolving culture. In
trying to explain human uniqueness many different critical
turning points have been suggested, such as the acquisition of
tools, the evolution of language, increasing group size, or
crossing the “symbolic threshold” (Deacon 1997, Dunbar 1996,
Mithen 1996). All these theories have in common the familiar
assumption that genes are the final arbiter, and that “adaptive”
means adaptive for genes or for the organisms carrying those
genes.
By contrast
memetics claims that the turning point in human evolution was
the advent of imitation. Indeed it is imitation that makes us
human (Blackmore 2007b). Once early hominids could imitate well
enough, they let loose a new replicator and, because of this,
their evolution shifted to an entirely new phase.
What does “well
enough” mean? As a general principle, replicators are more
effective when they are copied with high fidelity (accuracy of
copying), fecundity (number of copies made) and longevity
(lifetime of the copies) (Dawkins 1976). So we can imagine
imitation becoming good enough to set the new evolutionary
process going, and then memes competing so that those of higher
fidelity, fecundity and longevity increase in the newly growing
memepool. From that point on humans alone are the product of two
replicators, not just one. As Dawkins put it “Once this new
evolution begins, it will in no necessary sense be subservient
to the old.” (1989 p 193-4).
This flowering
of a new replicator was what I explored in The Meme Machine,
leading to a completely new way of understanding how humans came
to have such unique features as their excessively large brain,
true language, extensive tool use, a love of music, art and
religion, and complex culture. I argued that, by a process of
“memetic drive”, memes changed the environment in which human
genes were selected and so drove genes to produce ever larger
brains that were better at imitating the currently successful
memes. In this way our brains became selective imitation
devices, adapted to copying some kinds of memes more easily than
others (Blackmore 2001).
A good example
here is the evolution of language – long a highly contentious
issue with many competing theories (Dunbar 1996, Pinker 1994,
2007). On this memetic view language, like art and all of
culture, is not seen as an adaptation of benefit to humans and
their genes, but as a parasite turned symbiont. Indeed all of
cultural evolution is seen as happening for the benefit of the
memes and in spite of posing a threat to humans and their genes.
The human genes did, however, survive, but the creature that was
once their vehicle (i.e. the human body) gradually turned into a
better and better copying machine for the new replicator, the
memes. That is how we humans became such effective meme
machines.
Like Dawkins
and Dennett I am convinced that treating memes as replicators is
the way to understand human uniqueness and our evolutionary
origins. Furthermore I think it allows us to speculate about how
similar replicators may have evolved on other planets and what
this might mean for cultural evolution in the cosmos.
A universe of
replicators
We are able to
ask the question “Are we alone in the universe?” because our
distant ancestors began to imitate and therefore created memes
and language. We are able to contemplate communicating with
other worlds because our more recent ancestors invented new
copying machines and therefore let loose more replicators.
In all my
previous work in memetics I have deliberately used the term
‘meme’ to apply to any information that is copied between
people, or between people and artefacts such as books or
computers. I have often wondered whether ‘artificial’ memes such
as websites and high-tech goods deserve a different name from
‘natural’ human memes such as spoken words, skills, music, art
and religions, but have never found any principled way of
distinguishing them. So on the grounds that a false distinction
is worse than none I have stuck to the term ‘meme’ throughout.
However, being asked to write about memes in the cosmos has
forced me to think about this more deeply and to conclude that
there is indeed an important transition from memes copied by
human brains to information copied by technology other than
human brains. These ‘technological memes’ are riding on top of
both genes and memes to form a new layer of evolution. I’d like
to call them ‘temes’.
The
justification is this: replicators do not evolve on their own
but coevolve with the machinery that replicates them. In the
case of earth’s first level replicator, DNA, we have only a
sketchy understanding of its origins (Maynard Smith and
Szathmáry 1995) but we now see an exquisitely co-adapted system
of DNA and cellular copying machinery on which most living
things on earth depend. These living things can be thought of as
the “vehicles”, or gene machines, that carry the genes around
and protect them (Dawkins 1976), or as the “interactors” that
interact with the environment to produce differential effects on
gene replication (Hull 1988). In the case of human evolution
those vehicles eventually became the copying machinery for a new
replicator, memes. Could it then be that the memes will do the
same, building themselves meme-vehicles that in turn become the
copying machinery for a new kind of replicator, temes. I suggest
that this is what is happening all around us now.
The emergence
of a new replicator is probably always a complicated and messy
process (as it must have been with both of the first two
levels), but we may discern some important steps indicating a
new transition. When humans invented writing, about five
thousand years ago, this increased the longevity of memes as
compared with speech, and so new written memes spread along with
the skill of making them. But the process still required human
hands to do the copying, and human brains to select which texts
to copy and distribute. When printing was invented just a few
hundred years ago this increased both the fidelity and the
fecundity because many copies could be made quickly. It also
shifted the copying from human hands to the printing presses,
but human meme machines still did the selection. Subsequently,
new technologies have increased the fecundity, fidelity and
longevity in many new ways. For example, communications systems
spread memes over longer distances, and broadcasting increases
the number of copies sent out; sound and image recording systems
raise longevity by storing previously ephemeral information; and
new technologies raise fidelity enormously by making the shift
from analogue to digital recording. The systems that do this are
increasingly copying, storing and propagating information
without human help and at some point (which may never be
precisely pinned down) they deserve the new name of ‘teme
machines’.
I said that
these technologies are copying, storing and propagating temes,
but arguably the most significant shift is only now getting
under way; that is when the processes of variation and
selection, as well as those of copying and storage, move from
human meme machines to the new teme machines. This was hardly
happening at all in the mid 1970s when Dawkins invented the idea
of memes, but it is happening faster and faster now, just a few
decades later.
We can see this
in the invention of the World Wide Web and the search engines
that are essential to its use. We should remember how recent
this is, and how few people (if any) realised the significance
of search engines when they first appeared. Now we take them for
granted, and assume that if we want to know something the whole
of the web is at our finger tips. Their significance here is
that they are beginning to shift the job of selection of
information from human brains to teme machines. For most
searches a human still chooses what to search for, but the
results of that search are determined by numerous previous
searches and other aspects of the stored information, and there
are increasingly many ways in which software does the selection
rather than people. There are also sites that can write an essay
by selecting and recombining bits of old essays, or write poetry
or prose. Then there are evolutionary algorithms used to solve
problems in engineering, medicine or robotics.
Are these
systems true teme machines? If they carry out all three of the
essential processes of copying, varying and selecting
information outside of human control then perhaps they are, but
at the moment these processes tend not to be bound together into
something like a single organism. For example, books don’t carry
around their own printing presses, and cars don’t carry around
production lines; yet biological organisms do carry their own
replicating machinery around inside them.
Why? This is perhaps the same question that Dawkins (1982)
pondered when, in The Extended Phenotype, he asked why life is
packaged into organisms at all. If the answers from biology can
be generalised we might expect future teme machines to have all
three processes built into them.
This relates to
a question that has caused a lot of trouble for memetics;
whether memes have the equivalent of a phenotype-genotype
distinction. In biological evolution genes are not directly
selected. Instead they act as instructions for building bodies
(their vehicles or interactors) whose properties are the
phenotype. These phenotypic properties are (at least in large
part) determined by genes and in turn determine whether those
genes are passed on again or not. This is a highly effective
system because errors in building the phenotype are not passed
on in the genotype. Dennett (1995) describes it as a system for
retaining the “good tricks” that selection stumbles upon, and
Dawkins (1982) emphasises the design value of a ‘return to the
drawing board’ in each generation.
Superficially,
memes may not appear to work this way, and some critics have
argued that this disanalogy between genes and memes is a reason
for rejecting memetics (McGrath 1995, Midgley 2000, Wimsatt
1999). For example when people pick up a new saying, or hear a
tune or story and pass it on, they copy what they have heard. In
this case there is no obvious genotype/phenotype distinction or
replicator/vehicle separation (Aunger 2000). But if someone
copies the recipe for making a new kind of figgy pudding, then
it is easy enough to see the written recipe as a “memotype” and
the resulting pud as the “phemotype”; the analogy is quite close
because if Frederick makes a nasty mess of his pudding but
passes the recipe on to Frances, then Frances does not have to
follow Frederick’s mistakes. But what if Frances watches him
pick the figs, whip up the mixture, and set the oven? Then the
distinction is gone (Blackmore 1999). Some memeticists have
tried to work with a memotype/phemotype distinction (Benzon
1996, Speel 1997), but this has not been widely adopted and can
be very confusing.
I suggest that
a better way to understand what is happening is this: any system
that copies the instructions for making a product is better than
one that copies the product itself (Blackmore 1999). The
gene/vehicle distinction is precisely that; a system for copying
instructions (genes) for making living things (vehicles).However,
such systems have to evolve over time. In biology we are seeing
one that is billions of years old and has long ago achieved this
distinction. But when we turn to memes, they are at most a few
million years old, and we see a system still in flux. In some
cases a distinction has appeared, and very effective it is too,
but in other cases it has not.
Think of music.
Some people do listen to others singing or playing and then copy
the sounds directly, and in this case there is no
replicator/vehicle distinction. But most music is now produced
in recording studios and then copied in factories onto various
media, ending up listened to in homes, or via phones, MP3
players and other personal music systems. The information on a
CD or music file is instructions to create the pattern of
sounds. When someone hears the music they don’t copy it directly
but go and buy it or download it from somewhere else. So this is
all copy-the-instructions, and the CDs and digital players are
meme vehicles.
The same
applies to cars, clothes, fridges, furniture and almost all the
household goods we take for granted. Almost no one sees a table
they like and then goes out and cuts down a tree to make one
like it from scratch. Instead they go and buy a similar, or even
identical, one that has been produced from the same factory line
as the one they first saw. If lots of people buy a particular
model of car then the factory makes more from the production
line it already had. It does not copy the ones already out on
the streets.
Applying this
idea we can now see that technological evolution is rapidly
making the shift from copy-the-product to copy-the-instructions
for making a product. This is not because there is any inherent
goal for the process or any designer making it happen, but
because better replicators overtake poorer ones, and better
replicating machinery takes over from poorer machinery. If
downloading digital files from the Internet produces more, more
accurate, and more easily copied music than records, tapes, and
CDs, then digital files will take over. It’s as simple as that.
Another
important shift is also taking place. Much of our technology is
designed merely to store memes (such as books, CDs and so on)
but increasingly also to copy them. If the analysis here is
correct, then this is a critical step in the evolution of temes.
That is, the meme vehicles we have created themselves become
replication machinery for the next level of replicator. This is
equivalent to the step that occurred when hominid gene machines
began imitating and so became replication machinery for memes.
For now, we
earthly Pandorans are still needed for various stages in the
copying and selecting of temes, but teme machines are very
rapidly evolving and it may not be long before there are
self-repairing computer systems, self-maintaining power
stations, artificial systems for choosing which new technology
to build and which to ignore, and all the processes of
replication will be shifted out of the hands of humans and into
the world of teme machines. At this point the temes could carry
on even if the Pandorans all died out. We are not at that point
yet, but it is interesting to wonder whether we will get there
before we wipe ourselves out, or not.
With this
sketch of how replicators on earth have been doing we can now
move on to consider the general case of replicators anywhere in
the cosmos.
Extraterrestrial
memes
Who is out
there in the rest of the cosmos? Are there lots of other
cultures that have evolved in completely different ways from
ours? Are there lots of civilisations potentially capable of
communicating with us? Or are we all alone?
These questions
have been asked often enough, but in trying to answer them most
people have been searching for “extraterrestrial intelligence”
and so, I suggest, have got the emphasis wrong from the start.
From what I have said so far it will be clear that I want to put
the emphasis elsewhere, on how replicators arise, and what
happens when one kind of replicating entity builds on the
products of the previous one. From this perspective,
intelligence is a product of replicator power, not its
precursor: it is not intelligence per se that forces a great
leap forward in living creatures or creates the possibility of
culture, but the appearance of a second level replicator. This
second replicator creates an environment in which greater
intelligence is adaptive. Intelligence therefore increases,
helping to provide a situation in which a third level of
replicator can arise. This third level entails the creation of
replicating machinery outside of any original Pandora species; a
crucial step towards interplanetary communication, and so
towards the possibility of others communicating with us.
In 1961, the
astrophysicist, Frank Drake came up with his famous equation for
estimating the number of intelligent civilisations in our galaxy
capable of communication with us (Drake and Sobel 1992). He
never intended his equation to provide quick answers, but rather
to stimulate discussion and to direct research towards the
important factors involved. In the same spirit I would like to
suggest a different equation. Like Drake’s it describes the
number of intelligent civilisations in our galaxy capable of
communicating with us, but it begins with a guess at the number
of planets in our galaxy, ignores intelligence, and concentrates
on the appearance of replicators. This equation is
N = n x fR1 x fR2 x
fR3 x L
where N = the
number of intelligent civilisations in our galaxy capable of
communicating with us
n = the number
of planets in our galaxy
fR1 = the
fraction of planets in n where a first level replicator survives
fR2 = the
fraction of planets with R1 where a second level replicator
survives
fR3 = the
fraction of planets with R2 where a third level replicator
survives
L = the
fraction of a planet’s life for which a third level replicator
persists
We know far too
little to make sensible guesses about the values of most of
these fractions. Even so, the equation provides a useful
structure for thinking about the possibilities. I guess that the
emergence of each new level of replicator marks a danger point
at which the new replicator may simply fail, may wipe out the
next level down, or may wipe out all previous levels. If this is
right we can now make some further guesses about what may be
happening elsewhere.
No replicators
We don’t know
whether “replicating entities” are necessary, sufficient, or
both for life. If we assume both then all those planets which do
not have the conditions in which replicators can arise must
remain lifeless and therefore cultureless. Conceivably there are
ways in which culture could appear that don’t depend on
replicators, or on individual organisms constructed by
replicators, but if so I do not know how.
The First Level
Replicator R1
Possibilities: R1 emerges and fails
R1 emerges and sustains life
The first level
of replicator is the one that makes some form of life possible.
This might have evolved from an even simpler replicating
substance (e.g. a cheme (Szathmáry 1999)) or begun as a naked
replicator (such as a simple self-copying molecule) before
evolving to construct some kind of packaging or vehicle to
protect and propagate it. I will say little about this first
stage because it has been the subject of so much research and
debate. Nevertheless it is clear that there are probably a large
number of planets in our galaxy capable of sustaining a first
level replicator that creates living things. These living things
might be very different from any on earth. They might live under
seas, within the solid mass of their planet, in an atmosphere of
some kind, or they might roam on the surface. Conceivably they
might appear on asteroids or interstellar particles. The way
they develop will make it more or less likely that a second
replicator will emerge.
It is curious
that almost all life on earth depends on DNA and uses the same
(or small variations on the same) code for translating stored
information into instructions for protein synthesis. Whether it
is possible to have multiple replication systems operating side
by side, or whether one inevitably defeats all competitors, I do
not know.
Second Level
Replicator
Possibilities: R2 emerges in Pandoran species but fails
R2 emerges and kills Pandorans
R2 emerges, coevolves with Pandorans,
and sustains culture
A second level
replicator, R2, is one that emerges from a living thing created
by a first level replicator. That is, R1 builds vehicles, and
those vehicles become the copying machinery for R2, copying a
different kind of information with variation and selection.
This brings us
to where I began this chapter, with the idea that acquiring a
second replicator is a dangerous step. This is because the new
replicator (precisely because it is a replicator) will multiply
selfishly. Since there is so much misunderstanding over the term
“selfish replicator” I will just explain that this does not mean
that genes or memes or temes have plans, desires, or intentions;
it means only that their ability to multiply whenever conditions
are right means that they exert replicator power regardless of
the effect this has on anything else. This is all they can do,
for they are just information mindlessly undergoing replication.
The danger is
much like that of a parasite infecting a host. Conventional
parasites are built on the same replicator as their hosts, while
R2 parasites use a new replicator, but the principles may be
similar, as may the possible outcomes.
First, R2 may
emerge but never really take hold. This might happen if, for
example, its effects on individual Pandorans are harmful so that
individuals that do not acquire the copying ability die out,
leaving ordinary Pandorans to prevail. Or it might happen if the
conditions on the planet do not provide a sufficient advantage
to R2 for it to thrive . On earth it seems that if environmental
conditions change slowly then new skills are best dealt with by
R1 (assimilated into the genome), if they change fast each
individual is better to learn new skills for itself (individual
learning). Only when individual learning is too costly and the
environment neither too variable nor too stable is imitation
worthwhile (Richerson and Boyd 2005). Once copying is underway
it must be of sufficiently high fidelity, and there must be
enough individuals capable of it for R2 to take off. If these
principles generally hold true then there may be planets where
R2 appears but never thrives. There may even be planets where
this happens many times either in series or in parallel.
Second, R2 may
begin to proliferate but then prove to be lethal. It could be
that the new ability to replicate information is so energy
intensive that the Pandorans' resources are exhausted. It could
be that the things copied (behaviours, signals, chemicals or
whatever) themselves become lethal. Or it could be that R2
begins to transform the Pandorans into better R2 machines and
this transformation proves lethal.
Here on earth
the dangers of R2 included the high energy requirements of
building and sustaining a very large brain, and the danger of
death during childbirth for a species that walks upright and
therefore needs a narrow pelvis. Conventional theories attribute
the increase in human brain size to tool use, the acquisition of
language, or other adaptations of benefit to human genes, but I
have argued that it was meme driven and therefore potentially
dangerous (Blackmore 1999). In other words, the acquisition of
memes might have killed us off.
Third, if this
danger point is passed, R2 can become established on its planet.
To do this R2 must adapt to R1 and vice versa. In other words
the two replicators must coevolve. This may be a kind of arms
race with the R1 Pandorans striving to survive and multiply
copies of R1, while R2 strives to transform the Pandorans into
better machinery for multiplying R2. If the poor Pandorans are
not wiped out by this process then they become simultaneously R1
machines and R2 machines (more specifically, they remain R1
vehicles while becoming R2 replicating machines). The
information they copy one to another itself evolves and this is
what we call culture.
This whole
process is analogous to coevolution between parasites and their
hosts. So what determines whether a parasite will kill its host
or will coevolve to become symbiotic? There is evidence from
disease pathogens that when transmission is horizontal the
parasite is more dangerous than when transmission is vertical
(down the generations) (Maynard Smith and Szathmáry 1995). This
is interesting with respect to a second level replicator such as
memes. For example, it seems likely that early memetic
transmission was mostly vertical, within families, and probably
remained largely so during most of human evolution, which may be
relevant to the fact that we survived. But now transmission is
increasingly horizontal between peers rather than from parents
to their children, and may be correspondingly more dangerous.
Another
interesting question is whether it is possible for different
kinds of R2 to appear at once on the same planet, resulting in
multiple kinds of culture. Here on earth human brains are the
only ones to have been turned into meme machines, and humans
have the only significant culture. There is simple cultural
transmission in song birds, cetaceans and chimpanzees (Whiten et
al 1999) but not the kind of cumulative culture that marks a
fully evolving new replicator. This is reminiscent of the fact
that DNA has close to a monopoly as earth’s R1, and prompts
speculation as to whether there might be a general principle
here. It seems plausible that if two second level replicators
appear at once they will compete and the winner take all. This
might even be the reason for the curious fact that we humans are
the only remaining species in the hominid line. Perhaps
Neanderthals and other related species also embarked on an R2
transformation but either their R2 proved lethal (perhaps
through driving their heads to become too large for safe
childbirth or through copying dangerous traditions) or they
competed directly with early humans and lost. This is no more
than speculation but might just prove interesting by prompting
new hypotheses about what happened in hominid evolution, and
what might happen elsewhere in the cosmos.
Returning to
the possibilities for an R2 planet, the direction of cultural
evolution will depend on the kind of species in which that
culture first emerged, how much scope there is for transforming
that species into an efficient R2 machine, whether the species
has limbs suitable for constructing rich material culture, and
what material resources there are available for such
construction. The general principle will apply throughout that
replicators of high fidelity, fecundity and longevity will
prevail. This is likely to result in such innovations as
communication systems, behavioural traditions, education,
symbolic culture, tools and buildings. As the culture goes on
evolving it may produce analogues of writing (because it
increases longevity), long range communications systems (because
they increase fecundity) and digitisation of information
(because it increases fidelity). Gradually these may, depending
on conditions, create signals detectable far from the home
planet itself, but this only becomes a serious possibility once
the way is already paved for the emergence of a third level
replicator.
Third Level
Replicator
A third level
replicator, R3, is one that emerges from vehicles built by R1
and R2. That is, level 2 replicators build vehicles to protect
and propagate themselves, and those vehicles become the copying
machinery for a third level of replicator. On earth this is
occurring as memes (R2), use humans (R1 vehicles and R2
replicating machines), to build R2 vehicles and these become
machinery for copying temes (R3).
The
possibilities with three replicators multiple rapidly, and we
have little to go on when looking at our single planet for
clues. So I will not speculate much further but confine myself
to sketching out some of the more obvious possibilities. A few
such possibilities if R3 takes hold are listed in Table 1.
|
|
Outcome |
Remaining replicators |
|
1 |
R3
wipes out all of R1, R2 and R3 |
0 |
|
2 |
R3
kills R2 and its Pandorans; the rest of R1 survives |
R1 |
|
3 |
R3
wipes out all of R1 and R2, but R3 survives |
R3 |
|
4 |
R3
emerges and coevolves along with R1 and R2 |
R1, R2,
R3 |
|
5 |
R3
machines merge with R2 machines |
R1 R2/3 |
|
6 |
R4
emerges from R3 |
? |
The first
(disaster) scenario is one that may yet happen here on earth:
that is, R3 gets beyond the control of its Pandorans,
irreparably damages its planet, and so obliterates all life as
well as itself. This could happen through overuse of resources,
by causing drastic climate change, or by nuclear or other
accidents. A second, slightly less drastic, outcome is that a
planet’s Pandorans are all killed but other life forms survive
and can then begin the evolutionary process all over again. This
is perhaps a more likely outcome here on earth given the
widespread presence, variety and resilience of DNA based life,
especially bacteria and insects.
A third
possibility is that R3 coevolves with earlier replicators for
long enough to get to the point where it does not need them any
more, for example by creating self-repairing and
self-replicating R3 machines. It might then alter its planet’s
atmosphere, climate or resources in such a way that all the rest
of life dies out but the R3 systems survive.
If disasters
like this are avoided, the earlier replicators might survive in
several ways. As a fourth example, a stable symbiosis might be
reached with all three replicators coexisting. We have all three
on earth now but this is very recent and already serious dangers
are apparent. So it is impossible to judge how stable such a
system is likely to be.
Even if a
three-replicator system can survive I suspect that there would
be pressures for change. One change might be the merging of R2
with R3 machines. This is already happening here on earth with
the invention of neural implants and other prostheses, and with
the beginnings of the technology to create entirely artificial
creatures based on DNA. This might be one way in which the
descendents of earlier replicators might carry on in new forms.
Finally there
is the possibility of yet another level of replicator emerging.
What would R4 be like? It is hard enough to speculate about R3,
but my best guess is this. An R3 level culture might develop the
machinery to copy itself and so to seed new variants of that
culture on different planets. This would lead to competition
between variant cultures, and the evolution across the cosmos of
R4 level civilisations. If this happened, planets separated by
large distances would play a role analogous to islands here on
earth; creating relatively isolated conditions in which cultures
would evolve in different directions.
Note that the
vehicles of earlier replicators, such as biological organisms,
would not need to travel themselves as long as adequate
artificial vehicles had been built and could cope with the
widely different conditions on different planets. If it
occurred, this kind of colonisation of the cosmos ought to be
visible by its effects, and we have seen no evidence of it so
far. Perhaps this is because, like all the previous transitions,
the creation of a new level of replicator is dangerous.
Perhaps all the
transitions I have discussed are incredibly dangerous and we
earthlings are lucky to have got through to the third replicator
stage: perhaps the dangers are small, and the rest of the cosmos
is teeming with systems we have failed to detect. We do not
know. Indeed we have no idea how to assess the values of any of
the variables fR1, fR2, fR3, or
L but perhaps by thinking about evolution this way we Pandorans
may see a little more clearly what sort of child we have let
loose.
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