The Blind Watchmaker - Richard Dawkins on complexity and arms races

Lessons on evolution and complexity with Dawkins

The Blind Watchmaker, written by Richard Dawkins in 1986, is one of my favourite books in biology. Through this book, Dawkin introduces readers to several cornerstone ideas in evolutionary biology to explain the process of evolution and the emergence of complexity. While not all of it is up to date with recent scientific advances and discoveries, it remains a fascinating, accessible and enjoyable read. From the mental model of ‘genetic hyperspace’ to the forces of constructive evolution, this post will summarise the lessons that I took from Dawkin’s work.

Darwinian design and complexity

One of Dawkins’ goal in The Blind Watchmaker is to dispel the intuition or misconception that complex systems are always the product of grand design. Through evolutionary biology, Dawkins shows readers how diversity and complexity can emerge from ‘primeval simplicity’. It rests on the idea and evidence that non-random reproduction and hereditary variation can have complex consequences in the cumulative. It’s neither a theory of pure determinism nor pure chance.

“The only watchmaker in nature is the blind forces of physics… Natural selection, the blind, unconscious, automatic process which Darwin discovered, … has no purpose in mind. … If it can be said to play the role of watchmaker in nature, it is the blind watchmaker.”
Dawkins, Richard. (1986). The Blind Watchmaker: Why the Evidence of Evolution Reveals a Universe Without Design.

Introducing complexity

The topic of complexity itself is interesting. While it’s an attribute that we sense intuitively, Dawkins says it’s not something that we’ve defined very well. Maybe complexity is the emergent properties and proficiency of interacting systems. And in living things, this might include the ability to propagate. The difference between a bat and a human for example is one of design and complexity.

“The physicist’s problem is the problem of ultimate origins and ultimate natural laws. The biologist’s problem is the problem of complexity.”
Dawkins, Richard. (1986). The Blind Watchmaker: Why the Evidence of Evolution Reveals a Universe Without Design.

Hierarchical reductionism

In the study of evolutionary complexity, Dawkins’ approach is one of hierarchical reductionism. That is, to learn about the subcomponents of its organisation, and how they interact with one another. To use Dawkins’ lingo, the goal is to peel away at the hierarchy: to break problems down into simple units; to the point in which no further inquiry feels necessary to explain the physical phenomenon.

The challenge is in knowing where and how to focus one’s attention along the hierarchy. As Dawkins observes, we typically “peel” one or two layers down the hierarchy to achieve “satisfying explanations”. Richard Feynman shared a similar observation in The Character of Physical Law, likening the hierarchy of knowledge to an interconnected web of nodes. Since knowledge, insight and innovation can flow in many directions, we only need to choose a sensible place to start.

“If we wish to understand how a machine or living body works, we look to its component parts and ask how they interact with each other. If there is a complex thing that we do not yet understand, we can come to understand it in terms of simpler parts that we do already understand.”
Dawkins, Richard. (1986). The Blind Watchmaker: Why the Evidence of Evolution Reveals a Universe Without Design

The illusion of design

Grand design is an appealing idea because it’s hard to imagine how the complexity, diversity and absurdity of nature might have first come about. Dawkins believes two issues have contributed to this challenge. Firstly, our minds struggle with the timescales necessary to visualise evolutionary change. Since evolution has wired our brains for hunting and gathering, we aren’t well-equipped to grapple with microscopic or astronomical scales.

Secondly, we wrongly extrapolate our experience with technology, a result of a intentional design, with the machinery of life. For example, the biological technology in our eyes and ears did not emerge spontaneously. Rather, it’s the result of “gradual evolutionary stages by natural selection”. That’s not to say that this is all random or meaningless. There are forces and tendencies at work that shape the path trajectories, as we’ll soon discuss.

Accumulating small changes

“The answer, Darwin’s answer, is by gradual, step-by-step transformations from simple beginnings, from primordial entities sufficiently simple to have come into existence by chance. Each successive change in the gradual evolutionary process was simple enough, relative to its predecessor, to have arisen by chance. But the whole sequence of cumulative steps constitutes anything but a chance process when you consider the complexity of the final end-product relative to the original starting point. The cumulative process is directed by non-random survival”.
Dawkins, Richard. (1986). The Blind Watchmaker: Why the Evidence of Evolution Reveals a Universe Without Design

Sieves and selections

Dawkins shares several important mental models in the description of evolution with us. First is the idea of sieves and filters that dictate the path selection of systems. In the simplest of examples, Dawkins describes how the natural laws of physics sieve behaviour of solar systems. From an immense set of possibilities, these laws govern the paths that that the celestial bodies will take.

Shakespearean monkeys

Secondly, Dawkins makes the distinction between single-step sieves and cumulative selection. In biology, it’s chance in mutation and non-random cumulative selection that enables the “strange and wonderful” to emerge. The author recalls the somewhat humorous analogy that “given enough time, a monkey bashing away at random on a typewriter could produce all the works of Shapespeare”. The important caveat here is “given enough time”.

While a useful analogy for the evolution of life and complexity, it falls short in two areas: (1) cumulative selection is a non-random process that sieves for reproductive success; (2) the selection process itself has no long-term or ultimate goal.

“The reasons for survival are anything but simple — that is why natural selection can build up animals and plants of such formidable complexity. But there is something very crude and simple about death itself. And non-random death is all it takes to select phenotypes, and hence the genes that they contain, in nature.”
Dawkins, Richard. (1986). The Blind Watchmaker: Why the Evidence of Evolution Reveals a Universe Without Design

Traversing genetic hyperspace

It’s interesting to think about the recursive branches and potential trajectories of an evolutionary system. Variations in the starting conditions, mutations, and rules for selection can lead to very different future states. Future progenies too will differ greatly from their ancestors if given enough time and successive generations.

Here, Dawkins introduces to readers to the idea of a genetic mathematical space. Think of it as a hypothetical space to organise and categorise every creature and possible creature by its unique genetic formula. So, for every living thing that exists in this space, there exists many more, if not infinite, possible variations.

Dawkins says that evolutionary history is a one trajectory (of many) through this genetic space. It’s the result of chance mutations and non-random selection: “A particular path through the labyrinth of all possibilities”. This bares conceptual similarities to the hierarchy or network of knowledge that we talked about earlier.

“The actual animals that have ever lived on Earth are a tiny subset of the theoretical animals that could exist. These real animals are the products of a very small number of evolutionary trajectories through genetic space. The vast majority of theoretical trajectories through animal space give rise to impossible monsters. Real animals are dotted around here and there among the hypothetical monsters, each perched in its own unique place in genetic hyperspace.”
Dawkins, Richard. (1986). The Blind Watchmaker: Why the Evidence of Evolution Reveals a Universe Without Design

Space, search and selection

The idea above I think is a powerful mental model for complex systems in general. Dawkins parallels it to the search strategy of super-computer powered chess engines. These programs aren’t brute-forcing every possible move to make a decision. There are just too many possibilities in chess. Instead, these programs narrow their search space through effective and efficient search algorithms that programmers and Chess grandmasters have refined over time.

I’m reminded also of the challenge of technological lock-in. Businesses and governments for example are more likely to adopt certain technologies over others – Not always because of absolute advantage, but to the other selection pressures as well (e.g. industry or political inertia, resource constraints, opportunity costs of new R&D, and so on). This is well reflected I think in the diversity and history of energy policies across the globe today.

Irreversibility

Another interesting and related idea is Louis Dollo’s law of irreversibility. It states that organisms will not return to a prior state, even if their environment returned to prior conditions. There’ll always be some trace of their intermediary history in their evolutionary timeline. Dawkin’s says Dollo’s law is really a description of “statistical improbability”. While single mutational steps might be reversible, returning to a previous node on the genetic ‘hyperspace’ after successive generations of cumulative selection is extremely unlikely.

Convergence

That said, we can find strong examples of convergent evolution in nature, both across time and/or species. Since certain designs are better fitted to a given environment, different species on independent evolutionary paths may converge towards common design principles. This is a cumulative result of their environmental and selection pressures. Dawkins believes this is best demonstrated in the independent emergence of echolocation technology, both in biology and society.

“It follows that the echolocation technology has been independently developed in bats and birds, just as it was independently developed by British, American and German scientists.”
Dawkins, Richard. (1986). The Blind Watchmaker: Why the Evidence of Evolution Reveals a Universe Without Design

Evolutionary rate

When thinking about the rate of evolutionary change, it’s important to consider the mutation rate and selection pressure. Dawkins notes that natural selection ‘accepts’ and ‘rejects’ variations. This may have a braking effect on certain designs. But it’s the mutation rate, ultimately, that dictates the upper limit of the speed of evolutionary change.

The limits and rates of change are perhaps more interdependent in social complex systems. For example, greater selection pressures in technology, academia or finance may incentivise even higher rates of mutation (whether good or bad). In business, the Aesopian moral is relevant here: “The rabbit runs faster than the fox, because the rabbit is running for his life, while the fox is only running for his dinner.”

Origins and miracles

Evolutionary history has wired us with a subjective view of probability and risk – fit for day-to-day life. But our subjective view of what’s plausible can differ greatly from what really is. Dawkins observes how we can calculate the improbability of coincidences – the joint probability of improbable events – but struggle with imagining the array of what’s plausible. Our subjective views on likelihood might change when we extend our time horizon and ‘population calculation’. As Dawkins puts it neatly: “given infinite time, or infinite opportunities, anything is possible”.

Generatability and durability

For things to exist, they must have emerged recently, or possess qualities that allowed them to avoid destruction in the past. So, when thinking about the existence and evolution of systems, Dawkins says it helps to think about dewdrops (generatability) and rocks (durability).

In the context of modern life on Earth, the author describes necessary ingredients for cumulative selection to take hold. Firstly, there is the property of self-replication. Secondly, new copies of the replicators should be imperfect. Thirdly, replicators possess properties that influence their likelihood of replication. The second and third properties give replicators the opportunity to adapt to selection pressures over time.

“A central truth about life on Earth… is that living organisms exist for the benefit of DNA rather than the other way around. … The DNA itself exerts an influence over its own replication, via the attributes of bodies. DNA can be said to exert power over its own future, and bodies and their organs and behaviour patterns are the instruments of that power”.
Dawkins, Richard. (1986). The Blind Watchmaker: Why the Evidence of Evolution Reveals a Universe Without Design

Stone arches

In thinking about the emergence of cumulative selection, Dawkins introduces us to another useful analogy: an arch of stones. Dawkins puts it most succinctly:

“Stonehenge is incomprehensible until we realize that the builders used some kind of scaffolding, or perhaps ramps of earth, which are no longer there. We can see only the end-product and have to infer the vanished scaffolding. Similarly, DNA and protein are two pillars of a stable and elegant arch, which persists once all its parts simultaneously exist. It is hard to imagine it arising by any step-by-step process unless some earlier scaffolding has completely disappeared. That scaffolding must itself have been built by an earlier form of cumulative selection, at whose nature we can only guess.”
Dawkins, Richard. (1986). The Blind Watchmaker: Why the Evidence of Evolution Reveals a Universe Without Design

The reason I like this mental model is it helps one to think about the possible history of a system, and potential trajectories going forward. Whether we’re talking about evolutionary, technological or institutional progress, the spontaneous emergence of complex and proficient designs are often unlikely. Paths of incremental and adaptive changes across time are more common. And significant single-step deviations are less likely to confer fitness in their current environment.

Forces of constructive evolution

In cumulative selection, it helps to think of selection as a subtractive process, and mutations as an additive process. The ways in which they come together over time can give rise to complexity. As the author notes, “genes are selected, not for their intrinsic qualities, but by virtue of their interactions with their environments”. And there are, broadly speaking, two forces that propel this selection process: coadaptation and arms races.

Coadaptation

“An individual body is a large vehicle or ‘survival machine’ built by a gene cooperative, for the preservation of copies of each member of that cooperative. They cooperate because they all stand to gain from the same outcome — the survival and reproduction of the communal body — and because they constitute an important part of the environment in which natural selection works on each other.”
Dawkins, Richard. (1986). The Blind Watchmaker: Why the Evidence of Evolution Reveals a Universe Without Design

While we think of genes as ‘selfish entities’ that work towards their own propagation, coadaptation can emerge when genes find greater success through cooperation than ‘individualism or competition. Dawkins describes how gene cooperatives can give rise to organised bodies – ‘survival’ machines that help to preserve the genes of the cooperative.

The initial cooperative is an accident, there’s no advanced planning or grand design at work. But once the ‘lineage’ is established, the cumulative process becomes self-reinforcing. Climate favouring individuals and collectives enjoy greater chances of survival and reproduction. These bodies then join the ecology in which natural selection operates.

“Genes will be favoured if they are good at cooperating with other genes in the same gene pool. This is why large bodies of cells, working coherently towards the same cooperative ends, have evolved. This is why bodies exist, rather than separate replicators still battling it out in the primordial soup.”
Dawkins, Richard. (1986). The Blind Watchmaker: Why the Evidence of Evolution Reveals a Universe Without Design

Arms-races

The environment is also hostile, where the presence of different genes, cooperatives and species threaten each other’s chances of propagation. This selection pressure can produce arms races, the other driving force of evolution. An improvement or innovation on one side of the race will alter the environment and selection pressures for others. And cumulative selection is the mechanism in which successive generations adapt to changes in their environment.

“The kernel of the arms-race idea is that both sides in the arms race are improving from their own point of view, while simultaneously making life more difficult for the other side in the arms race.”
Dawkins, Richard. (1986). The Blind Watchmaker: Why the Evidence of Evolution Reveals a Universe Without Design

Feedback

Dawkins also makes the distinction between positive and negative feedback in cumulative processes. Positive feedback describes some attribute of runaway escalation. Negative feedback by contrast is the feature of “automatic control and regulation”. It helps to consider the accelerants, inhibitors and tipping points of a system. These ideas are interesting and relevant, not only in evolutionary cooperatives and arms races, but in modern socioeconomic systems as well.

Equilibria

In discussing the mating preferences and rituals of long-tailed birds, Dawkins shows readers how seemingly arbitrary starting conditions and choice discrepancies can lead to very different future evolutionary states. Likewise, under different starting conditions, mutation rates and selection pressures, the evolutionary system may have an equilibrium, several equilibria or no equilibrium at all. While I exclude Dawkins’ case studies here for brevity, I thought this was an important reminder given our tendency to rationalise in singular narratives.

Progression and allocation

Arms races, in isolation, suggests inevitable progression in competing generations, where ever-swifter cheetahs are matched by gazelles of increasing agility. Dawkins stresses to readers that the evolutionary system is far from geometric. Timescales, contingency and resources matter. Disasters for example can change the environment quickly and disruptively. Similarly, superior adaptation on one side may correspond to extinction on the other. Improvement can and does happen, but sometimes “spasmodically and interruptedly”.

Multilateral relations

Furthermore, Dawkins highlights that interactions in an evolutionary system are rarely bilateral. Species are competing or cooperating with one another in complex ways. While ecologies might exhibit emergent tendencies, their equilibria or attractor states are not necessarily obvious.

“Cattle eat grass, and might therefore be thought of as enemies of grass. But grasses also have other enemies in the plant world, competitive weeds, which, if allowed to grow unchecked, might turn out to be even more severe enemies of grasses than cattle. Grasses suffer somewhat from being eaten by cattle, but the competitive weeds suffer even more. Therefore the net effect of cattle on a meadow is that the grasses benefit. The cattle turn out to be, in this sense, friends of grasses rather than enemies.”
Dawkins, Richard. (1986). The Blind Watchmaker: Why the Evidence of Evolution Reveals a Universe Without Design

Opportunity cost

Similarly, plants and animals are not allocating resources and energy to competition alone. They are balancing trade-offs across various functions in life (e.g. hunting, mating, child-rearing, etc.). The cheetah that evolves to run faster is forgoing investment in other areas like milk production for their cubs. Natural selection will shape how each successive generation balances their trade-offs. As Dawkins explains, multilateral relations and opportunity costs help to explain why we don’t see and shouldn’t expect to see, cheetahs and gazelles running at Mach-5 speeds.

“The rabbit runs faster than the fox, because the rabbit is running for his life, while the fox is only running for his dinner. In economic terms, this means that individual foxes that shift resources into other projects can do better than individual foxes that spend virtually all their resources on hunting technology. In the rabbit population, on the other hand, the balance of economic advantage is shifted towards those individual rabbits that are big spenders on equipment for running fast. The upshot of these economically balanced budgets within species is that arms races between species tend to come to a mutually stable end, with one side ahead.”
Dawkins, Richard. (1986). The Blind Watchmaker: Why the Evidence of Evolution Reveals a Universe Without Design

Red queens and tall trees

Another potential consequence of arms races is Leigh van Valen’s principle of zero change in success rate. This is known also as the Red Queen effect. Dawkin’s illustrates the idea with a simple question: Why are all the trees in a forest so tall? If “all the other trees are tall, [then] no one tree can afford not to be” – A result of their competition and cumulative selection for sunlight. Each tree has invested resources and energy into growing taller, but for little relative gain.

These results bare similarity to the Prisoner’s Dilemma problem in economics. But trees aren’t planning in advance. Nor can they consider the net cost of successive generations or their system itself. Dawkins suggests that the Red Queen effect is fundamental to advancement. If one technology achieves superiority, then competing models may go extinct, reshaping the selection pressures and balance of powers.

“It is generally characteristic of arms races, including human ones, that although all would be better off if none of them escalated, so long as one of them escalates none can afford not to. Probably more so in fact, for all organisms are more seriously threatened by competition from their own species than from others. Members of one’s own species are competitors for the same resources, to a much more detailed extent, than members of other species.”
Dawkins, Richard. (1986). The Blind Watchmaker: Why the Evidence of Evolution Reveals a Universe Without Design

(A)symmetric arms races

With the ideas above, it helps also to distinguish between symmetric and asymmetric arms races. Symmetry pertains to races, like those of trees, where success (sunlight) and failure (no sunlight) is the same for all. Asymmetric races emerge between interacting players with different objectives. Dawkins believes asymmetric arm races tend to generate more complex designs – like the cheetahs and gazelles of the savannah, or missile and anti-missile systems in military warfare.

Diversity, ideology and analogy

One thing that struck me about the Blind Watchmaker was the breadth of theories at every twist and turn. In palaeontology for example, there is debate between the gradualists and punctuationists on the rate of evolutionary history. Similarly, in taxonomy, there are stark differences in methods between traditional cladists and pure resemblance measures (some borderline on ideology). One can see the diversity of thought and selection process of scientific enquiry at work. It’s a reminder too about the dangers of ideology and absolute confidence as we traverse the hyperspace of knowledge.

Finally, Dawkins makes a point about the benefits and dangers of analogy. It’s tempting to apply the mental models of evolutionary biology to other topics like economic development and technological progress. This post for example has drawn several parallels to social systems (so take caution!). While analogies can help us to illuminate certain problems, they can also cloud good judgement. We tend to see patterns, analogies, clusters and hierarchies in relationships and interactions that might or might not be. Here, Dawkins has some wise words for the road:

“The trick is to strike a balance between too much indiscriminate analogizing on the one hand, and a sterile blindness to fruitful analogies on the other. The successful scientist and the raving crank are separated by the quality of their inspirations.”
Dawkins, Richard. (1986). The Blind Watchmaker: Why the Evidence of Evolution Reveals a Universe Without Design

The Blind Watchmaker — Richard Dawkins on Complexity, Cumulative Selection and Arms Races