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Comment by raldi | Hacker News Reader

One of the greatest System Design stories of all time is the evolution of mammals.

Warm blood? A huge, complicated heart? Are you insane? The metabolism rates will be off the charts.

Record-breaking spin-up times before adulthood? Where the parent animals will have to actively care for their helpless young? And spend bodily resources to produce a fluid with which to constantly feed each one? How could they ever compete with a species that lays 10,000 eggs a year, dashing off after — or before — they hatch?

And yet, as They Might Be Giants put it, these disruptive designs, so seemingly flawed, made the difference between extinction in the cold and explosive, radiating growth.

P.S. Did you recognize the chicken-and-egg problem in the second paragraph?

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To me, this speaks to something entirely different: the idea that a complex system that works cannot be designed from the ground up, but must necessarily evolve from a simpler system that works.

This idea is known as Gall's law: https://en.wikipedia.org/wiki/John_Gall_(author)#Gall's_law

There are examples of complex systems created in a short time:

1. Manhattan project: The Hiroshima bomb was only tested once. The Nagasaki bomb was a different kind and never tested in advance. The whole infrastructure to produce those bombs was created from scratch within three years.

2. ICMBs: It required to shrink down nuclear bombs to put them on rockets, develop the capability to steer rockets precisely enough over thousands of kilometer, create a whole industry around the manufacturing. Then scale it up to hundreds of rockets.

3. Put a man on the moon. Nobody died at the first attempt.

You could consider those three steps as an example of Gall's Law as they build on each other. However, I would say each of them is a complex system in itself.

It depends on the meaning of "from the ground up".

I would argue that none of these things are complex systems, in the systems theory sense. A complex system is typically comprised of a network of casual relationships so deeply interconnected that its behaviour is not easily reducible (in the scientific sense of isolating individual behaviours to be examined). Human designs intentionally avoid this and instead strive for mostly linear causality, precisely so we can test and develop individual parts in isolation.

For an example of a complex system (and how unintelligible they are), see this diagram of metabolic pathways in the human body: https://www.sigmaaldrich.com/content/dam/sigma-aldrich/artic...

Is that how jets are designed?

yes, jets are composed of thousands of components, each attached to each other in assemblies. The assemblies are then integrated in such a way as to perform the functions of a jet: providing thrust, providing lift, steering, holding fuel, etc.

Most of these systems are evolutions from previous designs, however. How much is completely new?

They don’t call the F-22 and F-35 fifth generation fighters for no reason. There have been many iterative improvements since the ME-262 and Gloster Meteor that would not have happened without the intermediate steps.

To be fair, the last statement about extinction in the cold and explosive growth is largely due to the size of the brain. Humans figured out techniques to survive in the cold even while being warm blooded. No thick fur is necessary when we can just kill an animal and use its skin to get warmth. Then we discovered fire.

I'm talking about a disruption story that long predated humans: https://genius.com/7391311

> How could they ever compete with a species that lays 10,000 eggs a year, dashing off after — or before — they hatch?

This one sounds easy: by eating those unprotected eggs!

Well, yes — cold-blooded creatures usually have/had to go dormant at night (too cold to function) and they and their eggs were/are easy pickins for any warm-blooded mammal able to operate at full capacity during nocturnal hours.

They aren't flawed designs, they are simply optimized for better survivability of each individual offspring, at the cost of having fewer offspring.

https://en.wikipedia.org/wiki/R/K_selection_theory

>And yet, as They Might Be Giants put it, these disruptive designs, so seemingly flawed, made the difference between extinction in the cold and explosive, radiating growth.

These designs aren't seemingly flawed, they are flawed. Evolution produces flawed designs by "design".

Evolution trends towards survival. One thing critical for survival is equilibrium of the ecosystem so on a macro level evolution will trend towards equilibrium even if that necessitates the need for flawed designs.

In fact, flawed designs are critical to ecosystem survival. It works because competing designs to the flawed design are also just as flawed.

An invasive species on an island ecosystem is a perfect example of an over efficient design destroying a local ecosystem and in turn eventually destroying itself.

This is why ebola didn't spread as far as covid-19. Ebola is too efficient at killing thus reducing transmission rate and burning out the local ecosystem and thereby destroying itself before it got too far. The less efficient virus is the one that spread across the globe.

Poor choice of words on my part. When I said "flawed", I meant "unworkable, and less fit for survival than the competition"

Can you give a definition of "flawed" that doesn't make everything flawed?

An irresistible force can't move immovable objects and vice versa.

The fact that Ebola kills its host is actually a mal-adaptation. Killing the host is counterproductive, as then the virii in that host die as well.

The ideal virus is one that easily spreads and does no harm to its host, or even improves the survival of its host. Our bodies are full of these organisms, like our gut bacteria.

Yeah. SARS-CoV-2 has proven to be about near the perfect virus this year.

Not really, as the body kills the virus or the virus kills the body and then dies with it.

You could say Ebola is designed to live in another more competitive ecosystem where it’s abilities are rendered less effective thereby maintaining an equilibrium. This ecosystem is the illusive reservoir that epidemiologists are looking for. The suspicion is that this reservoir is bats and that bats have an immune system that can easily pacify the virus.

When the virus is introduced into humans it arrives as an invasive species overloading the habitat and destroying itself.

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