Complexity — David Krakauer, Part 2

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On: COVID-19 & Complex Time in Biology & Economics

Transmission Series Ep. 2

Episode: 27

Date: April 14, 2020

Evolutionary biologist.

Key Concepts

Review of 5 Transmission Essays

Key Concepts

Andrew Dobson: Need for disease models which capture key complexities of transmission.

  • Differences in transmission.
    • Not all infectious diseases spread faster in dense areas.
    • Diseases with a short-lived infectious stage:
      • Linear transmission.
        • Each individual infects a fixed proportion of other individuals.
      • Transmission is density-dependent.
      • Initial acceleration, eventual slow down.
    • Diseases with a longer-lived infectious stage:
      • Malaria, STDs.
      • Saturating transmission function.
        • For instance, mosquitos need to digest between blood meals.
      • Rate of transmission slows down in dense areas.
  • Differences in physiology, immune systems.
    • Different bio-mechanics = different immune systems.
    • In case of COVID-19, bats are better at controlling certain viruses:
      • Flight = hollow bones = less bone marrow = less B cells = less inflammation from overly active B-cells (such as in COVID-19 pathology).
      • Flight = high body temperatures = similar to fever = constrains viruses.
      • Flight = no body fat to survive during limited food = torpor during limited food = natural isolation = constrains viruses.
  • Differences in epidemic cycles.
    • Low inter-species transmission.
      • Epidemic cycles are distinct between species as each species interacts with the pathogens.
      • Species can co-exists.
    • Higher inter-species transmission.
      • Still distinct epidemic cycles between species.
      • Species with faster epidemic cycles (shorter life spans, faster reproduction cycles) may drive out species with slower epidemic cycles.
  • Concept of complex time.
    • Temporal phenomena play out across the scales of the complexity of the earth.
      • Evolution can be seen as the coupling and synchronizing of the organic clocks of various species.
      • As per the example above, if coupling among species changes, synchronization among species changes.

Michael Hochberg: The Importance of Timing in Restrictive Confinement.

  • The intuitions of a simple model.
    • In this case: the power of exponential growth, exponential thinking.
  • R0 = basic reproductive number.
    • COVID-19:
      • About 2.5.
      • Doubling every 3 days.
  • R needs to be reduced early to prevent an epidemic.
    • The size of the infectious population when measures are engaged is important in determining the degree of confinement.

Miguel Fuentes: Using Social Media Data to Detect Signatures of Global Crises

  • Technology allows for memetic transmission to be in advance of behavioral and biological transmission.
    • Can be spotted from social media patterns prior to an external event.
    • Sometimes, a memetic monoculture emerges:
      • Cliquish ideas dominate.
      • News that should reach us does not.
      • Micro (individual) and macro (population) merge.

Danielle Allen, E. Glen Weyl, and Rajiv Sethi: How to Reduce COVID-19 Mortality While Easing Economic Decline

  • Be as sophisticated in the treatment of socioeconomic networks as we are in the treatment of social epidemiological networks.
    • Multiple timescale approach.
    • Effective use of confinement testing and mobilization.
  • Mobilize-to-transition.
    • While in confinement: maximize virological and serological testing.
    • Move the resistant or immune subset of the population back into the economy.
    • Don’t wait for pandemic to subside.
    • Need for better testing technologies, certification.
    • Need for optimizing the allocation of testing (biases, revisions).
    • Need for reallocation of human resources across labor sectors (voluntarily).

Melanie Mitchell: How the Analogies We Live by Shape our Thoughts.

  • Flu:
    • Novelty of corona versus the known flu: higher uncertainty, more confusion.
    • Corona more virulent -> faster rate of penetration -> more concentrated systemic impact
      • 2 billion burgers at McD a year = no problem.
      • One order of 5 million at the drive-thru = big problem.
  • Tsunami.
    • Awareness of something with immense power that we’re not aware of until it’s too late.
  • War.
    • Positive: need to cooperate, sacrifices.
    • Negative: reduction in civil liberties, cooperation becomes control.
  • Analogies inform our behavior.
    • Allows us to arrive at insights without doing a considerable amount of formal work.
    • See also “The Master and His Emissary” on the role of metaphors.

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