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Chapter 2
Themes
Key
LitCharts assigns a color and icon to each theme in The Selfish Gene, which you can use to track the themes throughout the work.
The Gene’s Eye View of Evolution
Selfishness, Altruism, and Cooperation
Culture and Memes
The Unit of Evolution
Summary
Analysis
Dawkins thinks that humans are survival machines, and so are all other living entities on the planet as well, including “animals, plants, bacteria, and viruses.” On the outside, it seems like these organisms are all very different. But on the inside, the base chemistry of every living thing is the same: they all contain replicators (genes, or DNA) that are more or less the same type of molecule. This molecule is shaped like a double helix (or coil), and is made up of four kinds of building blocks (called A, T, G, and C). The only thing that’s different, between a man, another man, a snail, an octopus, an oak tree, and a fish is the order (or “sequence”) of their genetic building blocks.
Dawkins wants to replace the traditional scientific view of dividing living beings into different species. He focuses on what all living beings have in common: they’re all built by DNA (genes, or replicators). The only difference among species is the ordering of DNA building blocks. Species may look different, but they all function the same way: as “machines” built by replicators in order to survive.
Themes
Every cell of a body contains a copy of its DNA. DNA is a set of instructions (or “architect’s plans”) for how to build a body. Dawkins thinks it’s similar to imagining a building with a bookcase in each room containing the architect’s plans for that building. The bookcase is a “cell,” and it contains lots of binders full of loose pages. The binders are “chromosomes.” A human bookcase has 46 binders, and each page in each binder is a “gene.” The only difference with the metaphor is that there is no actual “architect” in the case of DNA. The DNA instructions wound up that way because of natural selection.
Dawkins uses the analogy of an architect’s plans to explain two facts about genes. First, architect’s plans contain instructions for making buildings, just as DNA contains instructions for synthesizing protein into organisms. If one imagines that a building (body) contains a copy of its own blueprints organized into binders (chromosomes) on a bookcase (cell) in each of its rooms, one understands that every cell in a body contains the full DNA for building a new body. Second, genes aren’t conscious. There’s no intent, foresight, or “architect” behind the “plan” for building an organism.
Themes
Architect’s plans have binders full of pages that come from people’s mothers and fathers. One’s mother’s sixth page of her third binder might say “build blue eyes,” and one’s father’s might say “build brown eyes.” One of those pages will end up in one’s own binder. Each sperm from one’s father contains 23 “binders.” When the sperm meets the egg (which also contains 23 binders), the pages from both sets of “binders” will be all mixed up and reorganized to create the set of binders that become the blueprints for oneself. They’ll be so mixed up, in fact, that it’s nearly impossible to figure out which exact page came from which parent. Genes are essentially shuffling around from body to body this way forever.
If an architect were to design a new building by taking half the blueprints (plans) from one building, and half from another building, and re-organizing their pages into a new set of binders, they would essentially be doing what nature does when the chromosomes of sperm and egg cells create embryos. A gene can pass from generation to generation intact, much like the way a page of instructions could be copied into a binder for a new building from an old one.
Themes
The actual picture is more complicated. Technically, a gene isn’t an exact “page” but a bit of information that might be a sentence long, half a page long, or three pages long. It might even be split up across several pages out of order. Dawkins thinks it’s unnecessary to worry about this though, as he’s just using “gene” to mean any bit of chromosome that contains instructions that can be passed on intact (however long, short, or mixed-up the instructions are).
Although genes are more complex than Dawkins’s metaphor allows, he’s not concerned. Dawkins uses the word “gene” to capture the function of DNA (and not its exact structure). A gene is any portion of DNA that replicates itself (is copied, more or less intact, into a new body through reproduction).
Themes
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Dawkins now explains how natural selection comes into the picture. Remember that genes are all copies of each other. Sometimes, there’ll be a copying mistake, say, one letter on one page is copied incorrectly. This is called a “point mutation.” Sometimes, the order will be wrong (it will be spelled backwards, for example). This is called an “inversion.” Sometimes, by accident, the different order connects bits of genetic material that actually work better together. Externally, this means the body that’s built will be slightly different. Internally, it means the new sequence will stick together more tightly and pass on in that new order instead.
Dawkins shows that the DNA replication process sets up the perfect conditions for natural selection to take place. All DNA has the capacity to replicate itself. If miscopies create slightly different replicators, they are technically competing for room on a chromosome in a sperm or egg cell. As noted, differential entities competing over finite resources trigger evolution by natural selection. Since this results in both external and internal (genetic) changes over time, Dawkins thinks it makes perfect sense to consider the gene the evolving entity.
Themes
Dawkins thinks that, because this is how natural selection works, the “thing” that is evolving must exist in lots of copies that can stay intact for long periods of evolutionary time. Genes have these characteristics. But individuals and species don’t. This also means that, technically, the gene is immortal. It lives on in copies or clones of itself, potentially forever (if it’s not miscopied). Genes are immortal coils of DNA. Individuals, then, are like temporary colonies or federations of genes that wind up living in the same body before they build a new one to move into.
Dawkins fleshes out his criteria for evolution to claim that replicators, by definition, stay the same over generations. They survive natural selection and therefore don’t get replaced. Genes fit this description since they clone themselves, whereas individuals or groups don’t. For example, a gene for blue eyes today is the identical clone of a thousand-year-old gene for blue eyes. But neither individuals nor species are identical to their ancestors, so it’s a poor fit to consider them the evolving entities.
Themes
A “good” gene will live longer if it makes a better survival machine to live in. For example, a gene that instructs its survival machine to have longer legs (to escape fast predators more quickly) will live longer in an environment where there are fast predators. This means that at the genetic level, the gene is always “selfish,” because genes that act in ways that preserve their existence win out in natural selection.
An organism is designed to allow the genes it contains to keep being passed on. Survival machines have one function: to keep genes in the gene pool. Dawkins reiterates that there is no altruism at the genetic level because genes won’t win out in processes of natural selection if they act against the interests of their own survival.
Themes
Of course, genes also cooperate since they share survival machines. Dawkins uses another metaphor to explain this phenomenon: oarsmen in a rowboat. An oarsman cannot win a race by himself. He needs several colleagues to fill up the boat, each in a different position on the boat, and each with a slightly different skill set. The coach decides which people to put together by shuffling the potential oarsmen into teams and seeing which combination performs better together. The oarsmen are the genes, and they are competing for seats on the boat. Each oarsman is selfish: he wants to win the race. But he also needs to work well with his teammates to do so. So, an oarsman who’s good at what he does and works well with other oarsmen will tend to be picked for the team.
Even though there is evidence of genetic cooperation, Dawkins still believes that all genetic behavior is fundamentally selfish. His metaphor shows that every oarsman (gene) selfishly wants to win the race. Winning a race stands for being successful in processes of natural selection. The oarsmen that do win races tend to row well together as a team. Similarly, genes that work well together build well-functioning survival machines, which makes them more likely to survive processes of natural selection.
Themes
Dawkins wonders why genes build survival machines that reproduce instead of just building bodies that last forever. He thinks that this is because evolution isn’t perfect. Some “bad” genes slip through the cracks. There are likely late onset “lethal” genes that become activated in old age (say, a gene for “senile decay”). Because they don’t cause the death of their survival machines before reproduction, they’ll be more successful at slipping through undetected, which explains why they still exist, and why humans die.
The phenomenon of death appears to counteract Dawkins’s claim that genes (and not species) survive. It would make much more evolutionary sense for genes to build survival machines that don’t kill a whole lot of genes by dying. Dawkins needs to explain why death happens, so he argues that death is an imperfect outcome of natural selection. A gene that tells protein to start breaking down in old age will have already successfully passed on its clones through reproduction. It survives natural selection at the expense of other genes (and survival machines), whether ones likes it or not.
Themes
There’s also another puzzle to think about. If genes are the things evolving, why do they build survival machines that reproduce and only pass on half their genes to the next generation? Dawkins thinks that’s because colonies of genes don’t care about staying together. There must be some evolutionary advantage to building a new body through reproduction, and likely the gene responsible isn’t concerned with the survival of other genes. It’s only concerned with its own survival. So, the gene cooperates with whichever other genes are necessary for it to keep replicating, regardless of which survival machine they come from.
Reproduction looks like it doesn’t make sense from the genetic perspective either, because it appears inefficient as a form of gene transfer, which makes it an unlikely candidate for natural selection. Dawkins doesn’t explain the evolutionary advantage of reproduction here (though he will later). Instead he emphasizes that clones of genes can easily coexist with compatible clones from other bodies. There is no evolutionary need for a level of genetic cooperation that keeps genes stuck together from survival machine to survival machine—that would imply a form of altruism among genes beyond what’s needed for an individual gene to stay alive, which Dawkins doesn’t believe in.
Themes
