The subtitle is The Universal
Laws of Growth, Innovation, Sustainability, and the Pace of Life in Organisms,
Cities, Economies and Companies and the author is Geoffrey West (2017).
The author is a theoretical physicist focused on complexity science
and emergent systems, but became intrigued by the question of why humans age
and die. And through his work, he came
to the unexpectedly fascinating result that all organisms scale with size in
mathematically predictable ways. Then,
taking it a step further, he was able to translate the science of his discovery
to a methodology that was applicable to cities and companies as well.
With all that as prelude, it really is an interesting book that has
new and insightful ideas on practically every page. I would do a disservice to try and write one
of my standard, pithy summaries. So, I
will try to encapsulate some of the main ideas, with the disclaimer up front
that much of meat is still probably getting overlooked.
As it relates to organisms, whether a shrew or a blue whale, the
fundamental building blocks of cells, mitochondria and capillaries are
appreciably the same in each. And as the
mass of any such animal grows, the related metabolic process tied to these
parts grows at a 75% rate, while the relative strength grows a two-thirds
pace. Succinctly, as an animal grows
bigger, its metabolic process becomes more efficient and the ratio of mass to
strength decreases. To wit: “the pace of biological life decreases
systematically and predictably with increasing size: large mammals live longer,
take longer to mature, have slower heart rates, and have cells that work less
hard than those of small mammals, all to the same predictable degree. Doubling the mass of a mammal increases all
of its timescales such as its life span and time to maturity by about 25
percent on average and, concomitantly, decreases all rates, such as its heart
amount, by the same amount.”
In looking at circulatory networks in groups as diverse as humans and
plants, the author notes that all have commonalities: “they are space filling, have invariant terminal units, and minimize
energy needed to pump fluid through the system.” They are all largely fractal in nature. And one of the interesting takeaways from the
structure of this system is that it helps to explain why organisms can have a
resulting size cap; because as the space between capillaries (the invariant
terminal units) grows, the ability to feed oxygen to the end cell users becomes
more challenged; therefore, the size of the specific creature finds its limits
when the chance of hypoxia increases.
Explained a little differently, because metabolism has a sublinear
growth rate (increasing at 75% relative to increases in mass and total cells), the
body reaches a point where the ability to repair and service new cells (the
interface between capillaries and cells) goes to zero because there are not
enough terminal units.
In applying these concepts to cities, there is a similar pattern
discovered: within any national system, as the population doubles, the
infrastructure needs only increase by 85%, but the socioeconomic factors (like
wealth, pollution, patents produced, crime, GDP) increase at a 115% rate. Scaling applies, just as it does with
humans. And in cities, the socioeconomic
activity grows at a superlinear rate, while infrastructure is more efficient,
which lends to the general precept that cities enhance social interaction and
lead to agglomeration effects.
One point that the author makes is that humans always die, but rarely
does it happens to cities. And in
thinking through this reality, he points to these differing sublinear and
superlinear growth rates as an explanation: “…the energy available for growth is just the difference between the
rate at which energy can supplied and the rate that is needed for maintenance. On the supply side, metabolic rates in
organisms scales sublinearly with the number of cells…while the demand increases
linearly. So as the organism increases
in size, demand eventually outstrips supply because linear scaling grows faster
than sublinear, with the consequence that the amount of energy available for
growth continuously decreases, eventually going to zero.” It is not just about growth, it also about repair
and maintenance. Every metabolizing
moment in our body creates entropy, and as we get older, the wear and tear
makes us less resilient, particularly as the units responsible for recovery
grow at a sublinear rate.
Quickly, West points out that companies tend to suffer from the same
phenomena as humans, which is why the large, large majority will disappear over
time. While the revenues and profits
tend to grow linearly, it leaves very little room for the inevitable perturbations
and disorder, and the resiliency of the company wanes.
In some respects, the author uses this work to sound the alarm on
sustainability, particularly as cities grow and grow as a function of human innovation. He believes that there is likely to be some
sort of singularity as a result, and suggests that we need to figure out a way
to tamp back the damage we’ve done to our planet if we want to prevent the
inevitable disruption. He clearly is speaking
to climate change, and without sounding like a Luddite, he believes that the answer
exists in harvesting solar power and desalination.
