Categories
linked down

Geoffrey West on Scaling Laws in Biology and Other Complex Systems

“Life is very likely the most complex phenomenon in the Universe manifesting an extraordinary diversity of form and function over an enormous range. Yet, many of its most fundamental and complex attributes scale with size in a surprisingly simple fashion. For example, metabolic rate (the power required to sustain the system) scales as approximately the 3/4-power of mass over 27 orders of magnitude from molecular levels up to the largest multicellular organisms.”

http://video.google.com/v…406426776765294

[video:google:7108406426776765294]

Randomly came across this video of a lecture given at Google by Geoffrey West on how biological “laws” scale. For example, flow through capillaries and metabolic rate scale from small to large organisms. What is mind-boggling is how metabolic rate scales “over 27 orders of magnitude.” The video is almost an hour long and is pretty dense, but the first 20 minutes or so explain the metabolic scaling, which is incredible. The last ten minutes apply the idea to social organizations (starting around 47 minutes in). Apparently, human organizations actually scale at 1.05 (versus 3/4).

The big takeaways for me: simply, for complex systems to work, they must scale. On a more complicated level, evolution is a blind process of trial and error that nonetheless created fantastically scalable, complex, decentralized systems that aren’t given to catastrophic failures. Therefore, it’s reasonable to postulate that, as opposed to using central, pointed, monopolistic planning (Think: few iterations) to design systems that scale without catastrophic loss, perhaps we should default to decentralized, immensely iterative trial and error as our basis for system design. The former is unnatural, the latter organic. The former is monarchistic, the latter anarchistic. The latter provably works whereas the former has failed over and over and over again.

Geoffrey West’s takeaway: “One, that inevitably [for biological systems] the bigger you are, the slower the pace of life—your heart rate decreases, your life span is longer and so on. In social organizations the bigger you are, cities in particular, the faster life is.”

Final note, I’m reminded of Gilbert’s super-replicator idea in Stumbling on Happiness.

The abstract on the video:

Life is very likely the most complex phenomenon in the Universe manifesting an extraordinary diversity of form and function over an enormous range. Yet, many of its most fundamental and complex attributes scale with size in a surprisingly simple fashion. For example, metabolic rate (the power required to sustain the system) scales as approximately the 3/4-power of mass over 27 orders of magnitude from molecular levels up to the largest multicellular organisms. Similarly, time-scales, such as lifespans and growth-rates, increase with exponents which are typically simple powers of 1/4. It will be shown how these universal quarter-power scaling laws follow from fundamental generic principles embedded in the dynamics and geometry of underlying networks, leading to a general quantitative theory that captures essential features of many diverse biological systems. Examples will include animal and plant vascular systems, growth, cancer, aging and mortality, sleep, DNA nucleotide substitution rates. These ideas will be extended to discuss social organisations such as cities and firms: to what extent, if at all, can we think of these as very large organisms and therefore as an extension of biology? Analogues to metabolic rate and behavioral times in cities scale counter to their behaviour in biology. Driven by innovation and the creation of wealth this has dramatic implications for their growth, development, sustainability and pace of life which, left unchecked, potentially sow the seeds for their collapse.

2 replies on “Geoffrey West on Scaling Laws in Biology and Other Complex Systems”

Asimov initial character in FOUNDATION was Hari Seldon, I am at last seeing a mind like this character in Geoffrey West. Does anyone else agree? He called this discipline psicohistory, of course written 50 years ago and without any singular data detailed in the book, but he, somehow, seems to have found a pattern in life and sociology, a new mathematical discipline able to predict, roguhly, and explain mainly everything.

Energy crisis of all past empires, roman, arab, british, american (wood, slaves, gold, machinery) patternos of development and growth and the energy involved.

Please make your comments if you wish, I´m not an expert. Thanks for reading.

Enrique, Spain.

Interesting – I personally don’t put a lot of credence into Asimov’s psychohistory as existence is way, way, way, too complex to make precise predictions about the future whether that future is tomorrow or in a week — much less when the future is out hundreds of years.

But West certainly seems like a bright guy!

Leave a Reply to Enrique Rocha Cancel reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.