I don’t recall how old I was when I first learned about Darwin’s theory of evolution, but I do recall being repeatedly amazed the more I read about what is surely one of the most extraordinary human intellectual achievements ever.
My go-to sources in this area have been Richard Dawkins and Stephen Jay Gould. Both are experts at explaining complex matters in a way that a curious layperson can understand. Dawkins does it in a straight ahead style, marshalling facts with military precision and drawing on analogies as needed to illuminate his points. Gould, in typically American fashion, leans towards an avuncular, storytelling style well suited to short articles, which is how he mostly shared his remarkable knowledge of evolutionary biology.
I am a huge fan of both. In fact, I’m a huge fan of any scientist who makes it their business to share their world with the rest of us. Reading the best of them is like bumping into a knowledgeable stranger on the beach holding up a strange shell with a look of wonder on their face, saying “Look what I just found!”
My love of science writing is matched by my distaste for the growing dismissal of science as just one possible view of the world, no more valid than any other. One place where that reaction is guaranteed to show up is when people - mostly creationists - dismiss the theory of evolution with the words, “It’s just a theory.”
In one sense, the assertion is unassailable. After all, scientists themselves call it the theory of evolution. So what’s the problem?
The problem arises through a misunderstanding (and in some cases a cynical fudging) of the meanings that words can have in a specialist setting. There are theories, then there are scientific theories. And they’re not always the same thing.
Like Stephen Jay Gould, let me illustrate with a story. Many years ago I saw a cartoon that I still think is simply wonderful. A grumpy, obviously rich businessman and his psychiatrist are sitting in the latter’s office, and the psychiatrist is saying to his scowling client: “My secretary has an interesting theory about you, Mr Smith. She thinks you’re just an asshole.”
In this case, the secretary’s theory is speculation, based on a little evidence with no rigorous testing and no attempts to prove it wrong.
This is the common meaning of theory; the one that you and I use in our daily conversations when we have an idea of why things might be the way they are but are not very certain - and may have no intention of testing our idea to see if it holds water.
It’s also more or less the original meaning of theory, a word that entered English in the 1590s from Greek and Latin. In Latin it meant “conception, mental scheme,” and for the ancient Greeks it meant “contemplation, speculation; a looking at, viewing; a sight, show, spectacle, things looked at”.
There’s no sense in there of anything especially rigorous. The secretary’s theory about the source of Mr Smith’s troubles is as valid as the psychiatrist’s, and both are simply a speculation, a viewing, things looked at.
In fact, it’s this definition that has the joke work. That and the fact that the psychiatrist himself is granting validity to this meaning of theory.
Somewhere around 1630, however, another meaning arose for theory: “an intelligible explanation based on observation and reasoning”. I theorise that it’s no accident that it emerged at the beginning of the Age of Enlightenment, as humanity began breaking free from the shackles of superstition and fear and embracing the view that the world was governed by natural laws that we could understand, if we were willing to look and think.
When an evolutionary biologist talks about the theory of evolution, they’re using theory in that later sense. Or, to paraphrase Wikipedia, “A scientific theory is an explanation of an aspect of the natural world and universe that that has been repeatedly tested and corroborated in accordance with the scientific method, using accepted protocols of observation, measurement, and evaluation of results … Established scientific theories have withstood rigorous scrutiny and embody scientific knowledge.”
Invariably anti-science and almost as invariably clinging to a worldview that is based on the flimsiest of evidence, people who dismiss the scientific view of evolution as “just a” theory grossly misunderstand (or misrepresent) the nature of scientific theories.
For those people, let me grumpily say a scientific theory is not a tentative idea about how things might be and possibly could be if only we had the tools to properly investigate them and find out for sure. The theory of evolution has been poked, prodded, challenged, tested and subject to Guantanamo-like tortures for a century and a half, and remains the best explanation we have for what we see in the fossil record.
It’s what led another evolutionary biologist, Jerry Coyne, to write a famous book with the provocative title Why Evolution is True.
It is to science’s eternal credit that it insists on using the word theory rather than fact. At its heart, science is based on the view that no matter the weight of evidence in favour of a particular view, it can never be the final word on a subject. Our models of the world are up for challenge any time, by anyone.
That view allowed Einstein’s theory of relativity to say that the Newtonian model of the universe breaks down as we approach the speed of light. It allowed the bizarre, paradoxical field of quantum physics to open up. Those advances made possible many of the technologies that you and I take for granted, including the GPS that helped you find your way to your cousin’s beach house last weekend and the lasers that open up the supermarket door for you each time you wheel out your increasingly expensive weekly grocery shop.
But there’s nothing to say that in the future someone won’t challenge the theory of relativity as incomplete. If their theory stands up to testing and scrutiny as Einstein’s has (so far), then that theory will prevail.
That approach could not be more different than that of the creationists. For them, it’s a God-given truth that the world was created a particular way, and they’re on a never-ending mission to seek evidence for it. No evidence can ever overturn the creationist view.
If there’s one thing I love about science above all else, it’s the openness to new discoveries and willingness to adopt new views in light of the evidence, as opposed to seeking evidence to shore up existing views.
The scientific approach calls for an openness that’s absent from cast-iron beliefs about the world. It acknowledges the limitations and fallibility of human understanding while, at the same time, harnessing our extraordinary capacity to uncover the most amazing things about the universe.
I don’t understand those who say a scientific approach to the world must be devoid of beauty or wonder. From where I look, a scientific mindset is a foundation for both those things. The remarkable story of life on Earth leaves me awestruck, and I’m grateful to those who’ve revealed it to us. They’re the knowledgeable strangers who transform an everyday walk along the beach into an experience of joyful discovery. They make life richer and more interesting. They remind me that the more we know, the more we realise how much more there is still to discover.
Bits and specious
Will AI disrupt book publishing? Wired magazine says no.
If you’ve yet to read Dawkins or Gould, I recommend Dawkins’ The Selfish Gene (1976) as a great place to start, and pretty much any of Gould’s collected essays. In 2017, the Royal Society named The Selfish Gene as the most influential science book of all time. The fact that it’s a rollicking read is a bonus.
It’s easy to imagine scientists in a given field comprising a cosy, collegial club of like-minded (and high-minded) individuals. It’s not always so. Dawkins and Gould, for example, clashed on important aspects of evolution such as the role of the gene and Gould’s theory of punctuated equilibrium (vs gradual evolution).
One of my favourite Gould essays, which also became the title of one of his books, was the 1990s Bully for Brontosaurus, in which he makes the case for retaining the name Brontosaurus for a dinosaur that had been officially renamed Apatosaurus. In 2015 a study found evidence that Brontosaurus was actually distinct from Apatosaurus and the name Brontosaurus was reinstated. Go Stephen!
Quote of the week
“What I don’t understand,’ Geoff says, ‘is why did the first fish, like the one who started land animals, suddenly decide one day to just leave the sea? Like, to leave everything he knew, to go flopping around on a land where no one had even evolved yet for him to talk to?’ He shakes his head. ‘He was a brave fish, definitely, and we owe him a lot, for starting life on land and everything? But I think he must have been very depressed.”
Paul Murray