Each Of You Is A Multitude, Here's Why

Our picture of life is going through a major shift. Ed Yong's book I Contain Multitudes reveals that a genome generally doesn’t contain all the genes an organism needs. Symbiosis isn’t rare, it's the rule. And we're just the icing on life's vast microbial cake. 


1. Your view of how life works, and of what you are, will be transformed by Ed Yong’s book I Contain Multitudes. It works like a text-microscope, a device to show you what you can’t otherwise see or fathom. It reveals seismic shifts are afoot in biology.

2.Life is often framed as a game of genes and genomes. Selfish genes cooperate with genome-mates, forming individual players (Dawkins’s “vehicles”) in evolution’s “red-in-tooth-and-claw” competition.

3. Yong calls that individual-centered view “a pleasant fiction.” Life takes large-scale cooperation (or partnerships) far beyond the inherited genome. For instance, human cells have ~25,000 genes but leverage ~500 times more microbial genes. Your body harbors ~30 trillion human cells and ~39 trillion microbial cells.

4. Humans and our cohabiting microbes (our microbiome) are so entangled that certain sugars in mother’s milk feed her baby’s gut microbes, not her baby (which can’t digest them). And such cross-species metabolism is very common.

5. A genome generally doesn’t contain all the genes an organism needs. Even anatomies aren’t just an unfolding of inherent traits. Bodies are “continuously built and reshaped,” by complex conversations with our surrounding sea of microbes.

6. By leveraging microbial genes, we can evade evolution’s slowness. They’re a form of fast intra-generational “adaptation,” letting us add biochemical capabilities we didn’t ourselves evolve. Microbiomes are like aftermarket add ons, or plug-and-play peripherals on biology’s “USB“ ports.

7. Yong’s “we” can be one of the widest “we’s” ever used—it often means all multicellular life.

8. So seismic are the shifts Yong describes, that they are shaking out new concepts, terms, and metaphors. For instance, holobiont, hologenome, horizontal gene transfer, and dysbiosis.

9. “Every natural animal and plant is a holobiont consisting of a host and diverse symbiotic microbes and viruses.”

10. So symbiosis isn’t rare, it's the rule. We (that wide we) have always been surrounded by teeming microbes. They arose 2 billion years before us. We plug into their biosphere. We’re the icing on a vast microbial cake.

11. One species relies so heavily on symbiont services that it has no mouth, no guts, no butts.

12. Symbiotic partnerships are of many kinds. The can’t-live-without-you kind. The harmless kind. The destructive/parasitic kind. They’re not conflict-free, and can shift kinds. But discernible principles govern stable survivable partnerships (e.g., suppressing selfish cheating for health of the whole).

13. This new worldview pushes Yong to try many new metaphors: You’re a garden, a zoo, a city, a colony, but most usefully you are multiple complex ecosystems (forearms = dry desserts, nasal cavity = moist jungles). That metaphor helps us reimagine immune systems as park rangers, not defending armies.

14. Yong feels microbes are badly branded. Most microbes aren’t our enemies (pathogens = a tiny fraction). And labelling microbes as “good” or “bad” often doesn’t make sense.

15. “Dysbiosis” is caused by microbiome imbalances (~like disrupted ecological webs). It’s implicated in many diseases.

16. How this alters biology’s big picture isn’t clear. E.g., whether it’s survival-of-the-fittest “hologenome” is hotly debated (see here & here, hat tip to Seth Bordenstein for that last balancing link).

17. I’d suggest enlarging Dawkins’s vehicle idea. Every gene needs its vehicle-mates to thrive, but also its microbiome genes, to varying degrees, sometimes just as much (suggesting selection might operate on this new kind of group level).

18. Microbial partners are non-genetically “inherited,“ passed on environmentally (like constructed niches).

19. Microbes run bustling gene-trading marketplaces, horizontal gene transfer is common.

20. Yong’s text skillfully zooms between biochemistry and the entire biosphere, entertainingly adjusting its depth of focus to reveal major changes. They’re almost like a biological Copernican shift, correcting a myopic individual-centered mindset. Yong says, “perhaps it is less that I contain multitudes and more that I am multitudes.”

Illustration by Julia Suits, author of The Extraordinary Catalog of Peculiar Inventions, and The New Yorker cartoonist.

LinkedIn meets Tinder in this mindful networking app

Swipe right to make the connections that could change your career.

Getty Images
Sponsored
Swipe right. Match. Meet over coffee or set up a call.

No, we aren't talking about Tinder. Introducing Shapr, a free app that helps people with synergistic professional goals and skill sets easily meet and collaborate.

Keep reading Show less

People who engage in fat-shaming tend to score high in this personality trait

A new study explores how certain personality traits affect individuals' attitudes on obesity in others.

Pixabay
Mind & Brain
  • The study compared personality traits and obesity views among more than 3,000 mothers.
  • The results showed that the personality traits neuroticism and extraversion are linked to more negative views and behaviors related to obesity.
  • People who scored high in conscientiousness are more likely to experience "fat phobia.
Keep reading Show less

4 anti-scientific beliefs and their damaging consequences

The rise of anti-scientific thinking and conspiracy is a concerning trend.

Moon Landing Apollo
popular
  • Fifty years later after one of the greatest achievements of mankind, there's a growing number of moon landing deniers. They are part of a larger trend of anti-scientific thinking.
  • Climate change, anti-vaccination and other assorted conspiratorial mindsets are a detriment and show a tangible impediment to fostering real progress or societal change.
  • All of these separate anti-scientific beliefs share a troubling root of intellectual dishonesty and ignorance.
Keep reading Show less

Reigning in brutality - how one man's outrage led to the Red Cross and the Geneva Conventions

The history of the Geneva Conventions tells us how the international community draws the line on brutality.

Napoleon III at the Battle of Solferino. Painting by Adolphe Yvon. 1861.
Politics & Current Affairs
  • Henry Dunant's work led to the Red Cross and conventions on treating prisoners humanely.
  • Four Geneva Conventions defined the rules for prisoners of war, torture, naval and medical personnel and more.
  • Amendments to the agreements reflect the modern world but have not been ratified by all countries.
Keep reading Show less