5: The Selfish Gene Theory
Life is the biggest mystery of all. People have been trying to figure out what it means and how it works for as long as people have been around. They’ve invented all kinds of religions, philosophies, and spiritualities to try to figure it out.
The first big question in trying to define life scientifically is: Where are you supposed to start? You can study biology, but that only gives you information and shows you how different things work together. It doesn’t really give you a context for all the information.
A few big clues are pretty self-evident. All of evolution is biology, all of biology is a product of evolution, all of biology is chemistry, and all of chemistry is physics. Atomic physics is basically the study of how electrons orbit protons and neutrons, and what happens as a result. Chemistry is the study of how large numbers of atoms interact with each other, and what happens when they do. Biology is the study of how chemicals interact with each other to create life and to make it work the way it does. Therefore, evolution is the study of how all those chemicals got into the arrangements they did, and how those arrangements change over time.
The jump between chemistry and physics is easy to make; chemistry is basically a specialized field of physics. From there you can make another jump to biochemistry, and see how fairly simple biological chemicals interact with each other to make simple biological processes happen, like how animals digest protein and carbohydrates and turn it into energy and body mass, or to see how people breathe in oxygen and breathe out carbon dioxide. But how do you write a chemical formula for an elephant?
Conceptually, the jump from biology to chemistry was as obvious as the jump from chemistry to physics. Biology is just a specialized branch of chemistry. In the entire history of biology no one has ever discovered a biological process that wasn’t made out of atoms of known chemicals or that didn’t work according to well-established principles of chemistry. The problem was that there were so many ways that atoms joined together as molecules and interacted with each other as chemicals, that it was hard to figure out how to break biology down into units of manageable size that would yield useful information, without leaving anything out. You could write a chemical formula for all the biochemical processes that take place in an elephant, but once you had, how would you be able to remember them all well enough to be able to use them? And even if someone could do that, how would they make the field of biology work by trying to do the same thing for every organism in the entire world? Biologists would die of old age before they could read that many books.
Dr. Richard Dawkins figured out one way to make a practical jump from biology to chemistry. This was a monumental discovery. He broke biology down to a reaction of critical chemicals. What chemicals would you have to remove from biology to make biology stop happening?
The answer is genes. With no genes, there is no biology. By removing food or oxygen you can make an organism die. But if you remove genes, the organism could never have been conceived in the first place.
This is another one of those things that seems so obvious it doesn’t even seem like a discovery. But what it does is to create a framework for all the other biochemical reactions.
What Dr. Dawkins figured out was how genes react with each other to create biology. Out of all the chemical reactions that happen in biology, it took a long time for biologists to sift through all the possibilities. Biology is basically a giant jigsaw puzzle, and once Dr. Dawkins figured out the most fundamental chemical reaction of biology, he’d assembled all the edge pieces of the puzzle. Now all the other biochemical reactions fit somewhere inside that outline.
This is a first principle. If you’re talking about biology, you’re talking about something that happens because of that fundamental chemical reaction. That gives you a reference point for writing chemical formulas for elephants that can never let you down. Every biochemical reaction, no matter how big, how small, how simple, or how complex, has to attach to that fundamental chemical reaction. That makes biology a lot simpler.
Evolution is the cumulative adaptation to environmental pressures. Charles Darwin discovered that by studying characteristics of animals. Richard Dawkins figured out how that worked at the bio-chemical level. Generation by generation, genes are passed down from parent to child. Occasionally genes mutate, and the parent passes down to their child a characteristic they themselves didn’t have. If that characteristic helps the child to survive and reproduce in their living conditions better than other members of its species, it has more children and spreads the new gene around to more of the next generation. If the new gene works well enough, eventually it will spread around to the entire species and the species will evolve.
The other, much simpler, way that evolution happens is by parents making different combinations of their genes in their offspring. Whichever offspring inherit a combination of genes that suits them better to their living conditions than the other members of their species pass the genes that made up that combination on to their own offspring. That’s a lot more complicated way for evolution to happen, but in the same way as evolution by mutation, over the generations, genes that work well in combination with other genes survive, and genes that don’t work well with other genes die out.
For instance, we still have genes for leukemia in our species because some people who carry the gene live long enough to have children and pass it on to them. Leukemia genes also kill people though, so obviously they’re not very good at surviving or at spreading through our species. That’s why a few people get leukemia, instead of most people, because a lot of leukemia genes kill themselves before they can be passed on.
The environment is whatever exists outside of the organism. Pressures are whatever conditions favor some characteristics over others. Adaptation is the change in the characteristics of a species, to fit it better to the environmental pressures. Cumuluative adaptation is continued adaptation to environmental pressures over the course of many generations. Hence cumulatlive adaptation to environmental pressures. This is how changes in living conditions create new species.
Charles Darwin discovered this without knowing about genes. He figured it out by studying how characteristics are passed down from one generation to the next, and what would happen if it continued over thousands of generations.
Dr. Dawkins figured out how evolution works for individual genes at the molecular level. He called his theory the Selfish Gene Theory, which he spells out in his book The Selfish Gene. Emphasis on Gene. It’s a book and a theory about the selfishness—meaning self-interest—of genes, not a book and theory about genes for selfishness.
The universe favors stable chemical reactions over unstable chemical reactions for the simple reason that stable chemical reactions keep happening, and unstable reactions stop eventually. This is the technicality in the economic system of the universe that makes the economic system of life possible.
A river is an example of a stable reaction—not a chemical reaction, but a physical reaction. The river exists because water molecules keep flowing along the same course. They aren’t the same water molecules, but they are acting the same way in the same place, because water always runs downhill, and the riverbed is the lowest point of the landscape and flows downhill to the ocean.
Rain is another stable reaction, and this is a chemical reaction. Water molecules suspended in the atmosphere are lifted by warm air rising. When they cool to the dew point, they condense around dust particles. Then they fall out of the atmosphere. They’re all made out of water, and water molecules everywhere stick together in the same basic way. That makes raindrops the same basic shape. They might be different sizes, or they might contain slightly different chemicals in addition to the water—like acid rain, in particular—but minor difference aside, they all work the same way. Each raindrop only exists for a little while before it hits the ground and turns into plain old water, but more raindrops just like it keep forming. Based on everything scientists know about water and rainfall—which is a lot—raindrops as we know them have existed ever since the world began. Not only that, but any planet in the universe that has the same size and mass as Earth, an atmosphere, and temperatures where water can vaporize and condense, has all the things it needs to create raindrops just like ours.
Biology is also a stable chemical reaction. That’s why life continues on Earth instead of dying out. (Or at least, that’s how it’s worked for the past 3 1/2 billion years. What’s going to happen to life on Earth in the next century is the big question.)
Biological organisms are created by genes. Genes are just really complicated molecules.
Genes are made by different combinations of protein molecules that bind together. Genes are basically bigger molecules made up of smaller molecules. (Technically it’s a little more complicated than that, but that’s how it works, anyway.)
Genes then bind together into chromosomes, which are even bigger molecules. A chromosome is a DNA molecule. When people talk about people’s DNA molecules, they’re actually referring to 46 DNA molecules that people carry, even if they don’t realize it—in other words, their 46 chromosomes.
Each gene survives by helping the organism that carries it to survive. Each organism passes on its genes by surviving and reproducing.
When you—or any other organism—create your sperm or egg cells, your cells break up your chromosomes into genes. Then they recombine the genes into new chromosomes. These new chromosomes are made up of your genes, but they’re unlike any other chromosomes in your body.
The new chromosomes work the same way as your normal chromosomes, because each of your genes occupies the same place in the new chromosome as it did in the old chromosome. What’s changed is the combination of genes that make up each chromosome—some came from one of the original chromosomes, and some came from the opposite chromosome of that pair.
In other words, you inherited half of your chromosomes from your mother and the other half from your father, even though they themselves didn’t have those chromosomes. Now you’ve mixed the genes from your mother’s chromosomes together with the genes from your father’s chromosomes to create new chromosomes made up of genes that came from both your mother and your father. This is what you pass on to your children, and this is what your own parents passed on to you.
When the sex cell divides, one of each of the chromosomes ends up in each cell. Now you have two cells that each carry one of each of the 23 pairs of human chromosomes.
When the 23 chromosomes in your sex cell combine with the 23 chromosomes in your partner’s sex cell, now you have a fertilized egg, with 23 pairs of chromosomes again. So you’ve conceived a new human.
(And remember, we are talking about a chemical reaction here. There is no evidence to indicate that a divine power imbues a fertilized egg with a human soul at the moment of its conception, or at any other time, for that matter. Some people who believe in imaginary things believe that happens, but I’m not here to talk about psychological defense mechanisms, I’m here to talk about science. Actually, when you put all the science together into one place, it indicates that a woman who is prevented from getting an abortion is being forced to reproduce against her will, which means she’s getting raped by her government. Anyway…)
That’s how the chemical reaction of the replication of genes works, and that’s the chemical reaction that life can’t begin without.
We see genes as being a part of us, because our genes make us what we are. We assume that life is a process of organisms passing their genes down from one generation to the next. But that’s misleading. We are a product of that chemical reaction; we are not the chemical reaction itself.
This is where things start to get really weird. The easiest way to explain the next part is to back up to the origins of life on Earth.
The Earth is about 4 1/2 billion years old. Life first evolved on Earth about 3 1/2 billion years ago. We have no way of telling exactly what started the process, but we can tell what that process had to be. There are various ways that scientists have hypothesized that life could’ve begun; what isn’t in question is that whatever began the process, it was some sort of stable chemical reaction that led to cumulative adaptation to environmental pressures.
The simplest explanation is called the Primordial Soup Theory. For the first billion years of our planet’s existence, chemicals were getting mixed together all over the planet and infused with energy from sunlight, radiation, lightening, and volcanic eruptions.
At some point, somewhere on Earth, a stable chemical reaction began. A molecule was created that reacted with other chemicals in a way that created another molecule just like itself, without turning the original molecule into something else. That’s an unusual way for a chemical reaction to work. Most chemical reactions don’t work that way. But some do. That’s how salt crystals, ice crystals, and diamonds form.
Scientists have replicated some of the steps leading up to this original biological reaction. They have figured out how to mix some chemicals together, add energy, and create amino acids. Our bodies are made of amino acids, and normally amino acids are created by living organisms. Basically, these scientists have figured out how to create life out of mud.
Scientists haven’t yet figured out how to create genes out of mud, but actually that’s a good sign. Scientists have been conducting these experiments in a few places for the past 40 years. The original chemical reaction covered the entire surface of the Earth for a billion years, and it only needed to succeed once. If scientists had figured out how to replicate a chemical reaction like that so easily, that would actually suggest that the Primordial Soup Theory was wrong, because if it was that easy for life to evolve out of mud, there would be so many alien life forms in the universe that we should’ve found signs of some by now.
This original biological reaction was different from salt crystals replicating themselves because this reaction used carbon and hydrogen atoms, and the whole planet was covered in those. So the reaction could spread all over the world pretty quickly.
Sometimes things would go wrong with the chemical replications, and molecules would be created that were slightly different from the original molecules. This happens with crystal reactions too.
Eventually, these new molecules spread all over the Earth. That means that eventually they used up all the carbon and hydrogen that was lying around. That means that the original chemical reaction came to an end.
By now there were numerous types of molecules in the world. Some of them couldn’t keep replicating now that there was no free carbon or hydrogen left. But some of them could take their carbon and hydrogen from other molecules and keep replicating themselves. In a sense that made them the first predators in the world. But in a much bigger sense, we are still talking about a chemical reaction here.
Now there were several new things that continued stable reactions depended on, but there were some molecules at least that could do all of them.
Molecules that could replicate faster than other molecules had an advantage at replicating themselves, because they could create more of themselves over any given length of time.
Molecules that replicated themselves accurately had an advantage over molecules that couldn’t replicate themselves accurately, because the more often a molecule created a molecule that was different from itself, the more often it would create molecules that couldn’t replicate themselves.
Molecules had to be able to eat other molecules now, because that’s where all the molecule-food was now.
And all the molecules had to be able to defend themselves against getting eaten by other molecules.
Any type of molecule that couldn’t keep its own chemical reaction going died out, and was replaced by molecules that could keep their chemical reactions going.
One of the defenses that the molecules that survived this part of the story had was the ability to cause other chemical reactions that built protective walls around themselves out of other chemicals. So now we have the original cells.
Then some of the gene-molecules started sticking together with other gene-molecules, and improving the success of their chemical reactions that way. That let them combine their abilities, so each could benefit from the other. We aren’t talking about cooperation here, we’re still talking about a chemical reaction that’s becoming ever more stable by a process of elimination.
The cells these original molecules were building now were basically machines they were using to build new replicas of themselves. We could call them genes at this point, but we could just as easily call them organic nano-technology. Not that they had to be designed by anyone, divine or otherwise.
Then some cells started sticking together after they replicated, and improving the success of their chemical reactions by doing things in conjunction that they couldn’t do on their own. Things like making themselves harder for other cells to eat, and making it easier for them to eat other cells.
That’s pretty much all there is to say about that part of the story. Now fast-forward 3 1/2 billion years.
The reason this scientific story of the origins of life is so useful is because you see that story continuing in every living thing you ever look at.
Every organism alive today is made of cells that work the same way the original cells did. We are all machines that our genes built to help replicate themselves.
A lot of people hate this part of the story, because this is where serious questions about the nature of free will begin to arise, and I have to dispel a lot of superstitions.
When you put all the science together in one place, it disproves the existence of free will. What we have instead is something that seems so much like free will that usually we can’t tell the difference. But that’s only because so much of your decision-making happens in your subconsciousness, that you never notice it. I’ve got a lot to say about that over the course of this book.
Our genes created something that seems like free will to us because they needed to be able to make our bodies move. The same is true for any animal. So we’ve evolved a lot of genes for creating sensory organs, brains, nerves, and muscles that we use to move our gene-replication machines around. As usual, these things evolved because the animals that had genes that didn’t build sensory organs and brains and muscles that worked as well as the others, didn’t replicate their genes—natural selection, in other words.
There are two important conclusions that can be drawn here.
First of all, our brains are organs for replicating our genes, in the same way that all of our organs contribute to replicating genes. There isn’t any part of our brain that contains a “replicate genes” center. The replicate genes center is our entire brains. To use computers as a metaphor, we have programs for doing different things like eating, running from tigers, and having sex. But “replicate genes” isn’t a software program, it’s the programming language that all the programs in our brains were written with.
Second, if our entire brains had been created by a single gene, we would be robots. What we have instead are brains created by a lot of genes that each create different parts. Each gene does whatever it does because that’s what keeps its replication reaction happening. That combination has worked better for our genes than any other combination, which is why our brains evolved the way they did, instead of any other way—because every other combination of genes died out. Obviously there is still a lot of variation within our brain gene pool, which is why we’re all unique individuals. But just as obviously, there are limitations on that variation, which is why humans are born with human brains, polar bears are born with polar bear brains, and so on.
The genes don’t control us, all they can do is to build our brains and start them up. Whatever happens next happens as a result of all of those components working together.
Now this is the part where people always ask me if our brains were built to replicate our genes, why don’t we all have as many children as possible?
You’ve answered your own question. Having as many children as possible isn’t always the most effective way to replicate your genes. Replicating your genes effectively also depends on raising some of your children at least to adulthood. The more children you have, the less effort you can devote to raising each of them. That means that replicating your genes depends on striking an optimal balance between quantity and quality of children. That optimal balance depends on your environment, like, how much food is available, but also the chances that each of your children is going to grow up instead of being killed by wars or plagues. We have genes that create parts of our brains for figuring those things out too, even if we don’t realize we’re using those parts of our brains.
Hence the reason people can choose not to have any children, even though their brains were created to make them replicate their genes. For some individuals, the combination of all the things that get put into their brains end up working against each other, and they decide to let their genes die out. The simplest way to explain that is that all the things happening in the person’s brain make them feel like they’re replicating their genes, even though they aren’t. The brain-program can only tell whether it feels like it’s carried out its purpose; but that doesn’t prove anything. Some individuals end up with brains that work that way, but as a species, the combination of genes that create our brains works pretty well for replicating our genes, which is why our population keeps growing.
But now that stable gene-replication reaction has gone out of control. What has been a stable chemical reaction to this point ultimately will run into the physical limitations of the Earth. Now if our population is going to survive, instead of destroying our environment and killing ourselves, we are going to have to figure out how to make everyone’s brains work in ways that will make our population stop growing.
Dr. Dawkins spells his Selfish Gene Theory out a lot more in his book, and you can learn more there if you want. People engage in altruism, sharing, caring for the sick, and everything else they do that seems unselfish as a result of their gene-replication brain-organs perceiving that the benefit to helping someone else is greater than the benefit to not helping them. Altruism is mutual aid, which means aid that will be returned to you in one way or another—even if it’s never repaid directly. Altruism is not voluntary slavery.
Now this brings us back to the outline of all of biology as a chemical reaction. Everything we or any other animal ever do, we do in the attempt to replicate our genes—even if it doesn’t work. Without human genes, there wouldn’t be any human behavior, there wouldn’t be any human impact on the environment, there wouldn’t be any greenhouse effect, and so on. All of those things exist because of human genes replicating themselves.
That’s really all there is to tell about this part of the story. A lot of people always ask when we’re going to stop talking about chemical reactions and go back to talking about people. The answer is, we’re not—and that’s the whole point. Dr. Dawkins made the jump from biology to chemistry so completely that we can talk about all of human behavior as a chemical reaction. It’s so strange to most people that it usually isn’t convenient to talk that way, but it is useful sometimes. Any time it becomes useful, we can make the jump from human behavior to chemistry easily.