The Tortured Biologists Department
A sophisticated metaphor can bring vague scientific concepts into focus, help us explain complicated results and inform on how we generate hypotheses. There’s a tendency, however, with popular science writers to torture metaphors beyond all recognition. Nowhere, it seems, is this done more than to evolutionary biology.
In evolutionary biology we use the metaphors of competition and cooperation frequently. Science writers will often misunderstand the concept the metaphor aims to explain, or extract from the metaphor some unfounded interpretation of the biological data. First, competition is confused with zero-sum games. In reality, most competition requires a level of cooperation, such as not murdering your opponent to win a game of tennis.
It’s a profound mistake to take the dispassionate scientific data and attempt to extract some trendy moral teaching. This enables the author to elevate themselves morally above historical scientists, whilst making the profound mistake of anchoring their outlook in scientific data. There is much in Biology that we would do well not to take instruction from. Individual scientists may be influenced by contemporary thought, but the science stands or falls on whether it’s correct. Additionally, a scientific idea derived from antiquated moral thinking is not rendered correct or incorrect by progress in moral philosophy.
I recently read Pathogenesis: How germs made history (2023), written by a social scientist, Jonathan Kennedy. Of evolution, Kennedy makes a series of errors such that (1) Symbiosis is the ultimate form of cooperation; (2) The discovery of endosymbionts was the first suggestion of cooperation; (3) Prior to endosymbiosis evolutionary biologists were exclusively focused on competition; and (4) That Darwin had precluded the possibility for cooperation:
“Margulis’ theory fundamentally challenged the dominant Darwinian understanding of evolution. If evolution by natural selection was Smith’s notion of capitalism applied to floral and fauna, then what came be known as the theory of endosymbiosis had more than a hint of Marx’s vision of utopian communism: ‘From each microbe according to their ability, to each according to their need’.”
Endosymbionts likely began their collaboration as predator and prey. The mitochondria are organelles, that were once endosymbionts, that were once free-living bacteria. For the single-celled predator engulfing a smaller prey bacteria, it might benefit from the prey’s continued metabolism. Perhaps the prey conducts a metabolic function not present in the predator. Therefore, slower digestion might advantage the predator in competition with other members of the predator population. At the same time, providing a benefit to the predator can confer a competitive advantage to the prey microbe over other members of its population.
Eventually, the prey transitions to living as a symbiont; mutually dependent with the former predator. The transition from endosymbiont to organelle is moreso academic than from free living to co-dependent. The mitochondria are much reduced forms of their ancestral state. Most of what is left of the ancestral form of the bacterium is its energy producing molecular machinery. Critics of communism might think that the author is onto something here, but I don’t suspect it was the intention.
This error is repeated in Entangled Life: How Fungi Make Our Worlds, Change Our Minds and Shape Our Futures. Normally, I wouldn’t comment on a book that’s cover-to-cover pseudoscience, but with Sheldrake winning the 2021 Royal Society Science Book Prize, I ought to disentangle a small amount:
“Eukaryotes arose when a single-celled organism engulfed a bacterium, which continued to live symbiotically inside it. Mitochondria were the descendants of these bacteria. Chloroplasts were the descendants of photosynthetic bacteria that had been engulfed by an early eukaryotic cell. All complex life that followed, human life included, was a story of the long-lasting “intimacy of strangers.”
Any analogy should be made as accurate as possible before we derive ethical instruction from it. Key steps, such as the digestive intent of engulfment are not alluded to here. Let’s improve on this.
A human population (the engulfer) discovers another human population (the engulfed) that are extremely skilled in making a food of incredible nutritional value. At first, the engulfers canibalise the discovered population. In doing so, they also acquire the nutrients of this special food. This continues until the cannibals realise they could eat only parts of the body that the prey can survive. The prey continue to nourish themselves, and the parts eaten incrementally will be of higher nutritional value. Some are not enthusiastic about this arrangement, refuse, or are unable to satisfactorily prepare the food and are cannibalised instantly instead. Those that comply are spared. The former cannibals become unable to survive without this cuisine, but still lack the ability to make it themselves. Eventually, the engulfers become sufficiently technologically advanced that they figure out how to obtain the cuisine without the cost of maintaining the prey population. The final result is that each person has the brain of a former victim in a vat that directs a food preparation robot to generate the essential nutrition. The long lasting intimacy of strangers.
Ed Yong breaks this down excellently in I Contain Multitudes: The Microbes Within Us and a Grander View of Life (2016). Yong writes of microorganisms that benefit us hugely, but that the continued benefit depends, selfishly, on whether it benefits them:
“Symbiotic microbes are still their own entities, with their own interests to further and their own evolutionary battles to wage. They can be our partners, but they are not our friends. Even in the most harmonious of symbioses, there is always room for conflict, selfishness, and betrayal.”.
Yong reiterates that:
“We cannot simply assume that a particular microbe is “good” just because it lives inside us. Even scientists forget this. The very term symbiosis has been twisted so that its original neutral meaning — “living together” — has been infused with positive spin, and almost flaky connotations of cooperation and harmony. But evolution doesn’t work that way. It doesn’t necessarily favour cooperation, even if that’s in everyone’s interests. And it saddles even the most harmonious relationships with conflict.”
So what did Darwin say about cooperation 160 years ago? Suggesting that Darwin precluded the possibility of cooperation is incorrect. In On the Origin of Species, Darwin outlines potential falsifications of Natural Selection. Among these, is that Natural Selection permits the emergence of traits helpful to other species, but with the requirement that they benefit the producer also. I’ll leave the last word to Charles:
“Natural selection will produce nothing in one species for the exclusive good or injury of another; though it may well produce parts, organs or excretions highly useful or even indispensable, or highly injurious to another species, but in all cases at the same time useful to the owner”.
