Yes. I assume you mean Margulis vs. Dawkins. Their disagreement is fascinating because it gets at a much deeper question than just “how does evolution work?”: what is the proper unit and mechanism of evolutionary change?
The basic beef
Lynn Margulis argued that conventional evolutionary theory overemphasized competition, random mutation, and individual organisms while underestimating symbiosis and cooperation.
Richard Dawkins, by contrast, is famous for emphasizing genes as the fundamental units of selection. In The Selfish Gene, he argued that organisms can be understood as vehicles through which replicating genes persist and compete.
So, very roughly:
Dawkins:
Evolution is fundamentally about differential survival and reproduction of replicators—especially genes.
Margulis:
That's an important part of evolution, but you're missing one of the great engines of evolutionary innovation: organisms merge, cooperate, and incorporate other organisms.
And Margulis thought this wasn't a minor footnote. She thought it radically changed how we should conceptualize evolution.
The example that made Margulis famous: mitochondria
This is the strongest part of her argument.
Your cells contain mitochondria, the organelles that generate much of the cell's usable energy.
Margulis argued that mitochondria originated as once-free-living bacteria that entered into a symbiotic relationship with another primitive cell and eventually became permanent residents inside it.
That's the endosymbiotic theory.
7The evidence is now overwhelming that mitochondria descend from bacteria. Chloroplasts in plants similarly descend from photosynthetic bacteria.
And this is a spectacular evolutionary event.
Instead of:
mutation → competition → gradual modification
you have something more like:
organism A + organism B → permanent biological merger → radically new organism
That's Margulis's big insight.
Where she challenged the standard Darwinian story
Margulis was particularly hostile to what she regarded as an overly adaptationist picture of evolution.
Imagine an organism acquiring a useful characteristic.
The conventional story might be:
- genetic variation occurs;
- some variants happen to possess a beneficial trait;
- natural selection favors them;
- the trait becomes more common.
Margulis didn't deny this.
What she objected to was treating that mechanism as though it explained most major evolutionary innovation.
She thought evolutionary history also contains enormous episodes of:
symbiogenesis — the creation of new evolutionary forms through the long-term incorporation of different organisms.
This is a fundamentally different picture of evolutionary creativity.
And this is where Dawkins becomes relevant
Dawkins wouldn't say:
“Symbiosis doesn't happen.”
Obviously it does.
The question is how to explain it evolutionarily.
Suppose two organisms cooperate.
Dawkins can say:
Fine. If the relationship increases the reproductive success of the genes involved, natural selection can favor it.
From this perspective, cooperation doesn't overthrow Darwinian selection.
It is something selection can explain.
Margulis was dissatisfied with this reduction.
She thought that saying:
“The genes ultimately benefited”
could become an excessively gene-centered way of describing what actually happened.
Her emphasis was instead:
The biological individual itself can be transformed through relationships with other organisms.
That's a major conceptual difference.
The really interesting disagreement: competition vs. cooperation
This is where the popular version of their disagreement gets slightly misleading.
Dawkins is not actually saying evolution consists only of organisms fighting each other.
And Margulis is not saying evolution is basically cooperation.
Both recognized competition and cooperation.
The disagreement is about what deserves explanatory priority.
Dawkins asks:
Which replicators are successfully propagated?
Margulis asks:
How did new biological individuals and evolutionary lineages come into existence in the first place?
Those aren't necessarily contradictory questions.
In fact, modern evolutionary biology incorporates substantial parts of both perspectives.
Margulis had an even more radical idea
She didn't just think bacteria occasionally cooperate.
She thought symbiosis was a major source of evolutionary novelty.
Consider the eukaryotic cell—the type of cell from which animals, plants, fungi, and protists are constructed.
It is itself a kind of historical community.
Mitochondria retain bacterial characteristics, including their own DNA and bacterial-like machinery.
So the “individual cell” isn't as straightforward as it looks.
Underneath the surface:
You are a composite.
And this becomes philosophically interesting.
The traditional picture of an organism is:
one organism → one genome → one lineage
Margulis's picture is much messier:
multiple organisms → interaction → merger → new organism → new evolutionary level
The organism itself can be the product of ancient cooperation.
This connects surprisingly well to what we were discussing about McKenna
There's actually a fascinating philosophical parallel.
McKenna's critique was:
We tend to mistake culturally constructed categories for fundamental reality.
Margulis does something analogous in biology:
We tend to mistake the organism as a fundamental unit when it may itself be a historical composite.
You look at a human being and think:
“That's one organism.”
But evolutionarily, you're a consortium of ancient biological histories.
Your mitochondria have their own evolutionary ancestry.
Your genome contains sequences acquired through ancient biological processes.
Your gut contains enormous microbial communities.
So the boundaries of the individual become philosophically strange.
But here's where Margulis went too far
This is important because Margulis sometimes turned a valuable corrective into an overly sweeping alternative.
She sometimes presented herself as opposed to the “Darwinian” or “neo-Darwinian” framework in a way that suggested symbiosis fundamentally displaced natural selection.
That's much harder to defend.
The modern synthesis and later evolutionary biology can accommodate symbiosis perfectly well.
In other words:
Margulis was right that symbiosis was enormously underestimated.
But:
that doesn't mean natural selection or gene-level explanations are therefore wrong.
The evolutionary fate of an endosymbiotic relationship is still shaped by selection.
And genes still replicate differentially.
So the contemporary picture is much more:
mutation + selection + drift + gene flow + developmental processes + symbiosis + horizontal gene transfer + ecological interactions + other mechanisms
rather than:
“Dawkins OR Margulis.”
The deepest disagreement
I think the most interesting way to formulate their disagreement is this:
Dawkins asks:
What is being selected?
Answer: ultimately, replicating genetic information.
Margulis asks:
What kinds of entities can evolution create?
Answer: sometimes radically new biological individuals through cooperation, merger, and symbiosis.
And those questions point toward two different philosophical intuitions.
Dawkins gives you a picture of evolution as fundamentally a competition among lineages of replicators.
Margulis gives you a picture of evolution as a history of both competition and biological incorporation, in which today's individuals can be yesterday's communities.
That's why the Margulis/Dawkins debate is more interesting than the simplistic “selfishness vs cooperation” framing.
The really profound question is:
Is nature fundamentally composed of competing individuals that occasionally cooperate, or are many of the “individuals” we see actually the historical products of cooperation and merger?
Margulis's answer was much closer to the latter.
And modern biology has, in an important sense, vindicated a significant part of her challenge—particularly the central role of endosymbiosis—without overturning Darwinian natural selection.
No comments:
Post a Comment