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Monday, March 13, 2017

Animals Screw Over Other Animals and Get Away With It

Book cover for "The Selfish Gene" (30th anniversary edition) Image source.
I recently read The Selfish Gene by Richard Dawkins. It's a book about how we should conceptualize natural selection as choosing between rival genes- not choosing between individual animals or groups of animals. And therefore, a gene always "selfishly" influences the animal (or plant, or whatever) to do things that benefit the gene itself.

This book has been criticized for being depressing, and yeah I can see why. The main point is, whatever thing is able to produce more copies of itself is the thing that will increase in number. The world will be full of them. That's the deciding factor. That's it. Even if it succeeds through cruelty and immorality, it still succeeds. If it gets away with it, then it gets away with it. And the world just goes on, but with more and more copies of whatever thing is able to copy itself best. No accountability, no justice. It's the responsibility of every organism to protect itself- if it's bad at that, it dies. And the world just goes on.

But let's start at the beginning. "The Selfish Gene" was published in 1976 and is still important today because of the groundbreaking way it explains natural selection to a lay audience. Here's the basic idea: among many people, including scientists, there is significant misunderstanding about how natural selection works. Natural selection chooses between replicators- the replicators that are best able to create more copies of themselves are the ones whose number increases. And what is a "replicator"? It's anything that is able to create identical copies of itself. Animals are not replicators, because an animal's offspring aren't exactly the same as the parent animal. No, instead, genes are replicators. The same gene can be passed down for hundreds and hundreds of generations. It lives in the bodies of many different individual animals, but the gene itself always stays the same. We can think of animals, plants, and other organisms as the "vehicles" which the replicators build to help them create more copies of themselves.

In this view, we can imagine that genes "want" to create more copies, and they "make decisions" about what kind of characteristics their vehicle (the animal/plant/etc) should have in order to increase the chances of passing on its genes. Obviously, genes aren't actually capable of "wanting" or "making decisions," but it's helpful to conceptualize things in this way. (Because really, the genes that aren't able to successfully create more copies would die off. The genes that exist are the ones that are able to copy themselves. So of course we can assume that, whatever effect a gene has on the organism it is in, it is an effect that helps the gene survive and copy itself. Imagining that a gene "wants" to copy itself makes this simpler to understand.)

In biology, genes are the replicators, and therefore, natural selection is choosing between genes. It is not about choosing between individual animals, or groups of animals. It is just about the genes. Natural selection chooses the genes which are best able to copy themselves. So the successful genes are the ones that are "selfish"- that always do what benefits themselves, even if it's cruel to others.

And how does a gene copy itself successfully? First of all, genes are copied when organisms reproduce- so the most important role of the gene is to help the organism survive and produce offspring. In that sense, the gene and the organism both have the same "goal" (though as I said, it's not literally true that a gene or an organism can have a "goal", with the exception of more complex animals with brains which are capable of that), which is to keep the organism alive. In this sense, the gene's "selfishness" also causes the organism to behave in a "selfish" way- to do what benefits itself, even if it comes at other's expense. For example, a tall tree can "selfishly" access more sunlight and block shorter plants from receiving any. The tree isn't doing this in a conscious way, and neither are its genes, but this is reality because it works. Trees that get more sunlight will be stronger and more able to reproduce. The tall tree screws over the other plants, and it works. It gets away with it. And so that gene- for growing taller- makes more and more copies of itself.

However, there are situations where a gene's "selfishness" will cause an organism to behave in an altruistic way. Specifically, an organism might do something which puts itself at risk but benefits a close relative who is likely to share the same genes. A mother animal will spend so much time and energy caring for her offspring. Her behavior is altruistic- she is helping her offspring at her own expense, but her genes are being selfish. If the offspring grow up healthy so they can reproduce, this means there are more copies of the mother's genes too. So from the gene's point of view, it's a good strategy to have the mother animal put herself at risk because the benefit to the offspring- who share the same genes- is huge.

Dawkins argues that all animal behavior can be explained this way. There must be some benefit to a gene's chances of survival- even if it's not necessarily good for the individual animal's chances of survival.

This book was fascinating for me because, really, it's about the mathematical field of game theory. From a gene's point of view, when is it beneficial to have an animal make a sacrifice to help another- for example, to help a cousin? Well, there is a 1/8 chance that the cousin shares the gene in question, so if the benefit to the cousin is more than 8 times the cost to the first animal, then it's worth it. (In reality, though, it's hard to say what exactly the relation is between members of a family of animals living together, and there are other factors to consider, like an animal's age and how that affects its chances to reproduce in the future- it's better to make sacrifices to help an animal that's more likely to reproduce.) Or, let's consider this question: Is it better for a young animal to leave its parents and have offspring of its own, or to stay and help raise its brothers and sisters? Its siblings and its offspring would both share 50% of its genes, so it's not clear which is a better choice, from a gene's point of view. And indeed, there are many species where its common for animals to help raise their siblings, even though they could go off and have offspring of their own.

(Note: When we use language like "shares 50% of its genes", we're only talking about genes which are rare, not genes shared by the entire species. Scientific research has found that all humans share over 99% of their DNA. We're not talking about that; we're only talking about the genes which are more rare, which you can't expect any random member of the species to have.)

Here's another interesting game-theory problem: Two members of the same species compete for food and other resources. Suppose you and another animal of your species both want the same food. What should you do? Should you fight them, or just give up? If you fight, there's a risk of getting hurt, even if you win. There are many different strategies, and it's an interesting math exercise to pit the strategies against each other. Keep in mind that the successful strategies will allow the genes to create more and more copies of themselves- in other words, if a strategy is successful, it means more and more of the population will use that strategy. So really, it needs to be successful against copies of itself. This is called an "evolutionarily stable strategy", or ESS.

For example, the strategy "the one that found the food first should keep it [and fight to keep it, if necessary], but don't fight if you weren't first" may be an ESS because, if all the animals use this strategy, it would be impossible for another strategy to appear and be successful in that population. Maybe you suddenly have a mutant animal which uses the strategy "always fight." This animal would end up getting in a lot more fights than others, and the cost of fighting so much would mean the animal is less likely to survive and reproduce.

However, the strategy "never fight" is not an ESS, because if everybody used this strategy, and then a mutant animal appeared with the strategy "always fight", the mutant would win every time, and the new "always fight" strategy would spread through the population. However, "always fight" does not do well against copies of itself, so it is not an ESS either. (For example, the strategy "if you are bigger than the other animal, you should fight; if not, you should give up and leave" would be wildly successful in a population where everybody else was using "always fight.")

The concept of an ESS is NOT "if everybody does this, it's beneficial for everybody." Nope. Instead, it's "if everybody does this, it's not possible for a new strategy to show up and successfully take advantage of us." You don't trust other members of your species not to screw you over just out of the goodness of their hearts. The only reason they're going to not screw you over is that it doesn't work.

And then there was the chapter about interactions between males and females. For species that reproduce sexually, the female provides the egg and the male provides the sperm, and eggs are much bigger than sperm. Therefore, at the moment of conception, the female has already invested more into the offspring than the male has. Really, from a gene's point of view, the ideal situation would be if the animal could just abandon its offspring and assume that its mate would care for them, and then it would be free to go off and have other offspring. Since the female has already invested more than the male, it's less of a risk for the male to abandon than for the female to abandon. And yes, we see that there are many species where the female animal does most or all of the work in raising the offspring.

Well, yeah, so that kind of sucks for females. The male can just dump off his sperm and then disappear, and the female has to do all the work. Males who use this strategy will end up having more offspring, and the genes for males abandoning females will spread through the population. It spreads because it works, because the animal gets away with it and there is no justice.

However, there are strategies females can use to deal with this situation. The book discusses two: the "domestic bliss strategy" and the "he-man strategy." In "domestic bliss," the female requires the male to go through a long period of "courtship" before she is willing to mate. She may require him to bring her food, or build a nest, or whatever. This way, at the moment of conception, the male has already invested heavily in the offspring, and would not want to abandon his mate and take the risk that some of the offspring would not survive. If the majority of the females in the population use the "domestic bliss strategy," it will no longer be a "successful strategy" for a male to abandon his mate.

In the "he-man strategy," females are very picky about which male they mate with. They choose a strong and healthy male who, presumably, has good genes. The strongest males in the population will have a big harem of females. The males won't help in caring for the offspring, but at least the females know that their offspring will have genes from a strong, successful father- maybe their sons will go on to have their own harems, and help the mother's genes spread even more. If we look at animal species in the real world, we can find examples of species that use the "domestic bliss strategy" and others that use the "he-man strategy." Even among humans, some cultures have a view of marriage and childbearing that's closer to "domestic bliss" and some closer to "he-man." Both are ESSes, so factors like environment and culture determine which one ends up spreading in a given population.

So basically that's how it works. If you can screw over other animals and get away with it, then you get away with it and have more offspring which will also cruelly screw over other animals. The only way to put a stop to it is for other animals to develop better strategies to protect themselves. There's no higher authority that judges and punishes cruelty. Nope. If cruelty works, then the cruel animals win, and that's that.

I mean, that just sucks, right? Many people have said this book is depressing, and yeah, it is. (However, Dawkins says that humans should not just be selfish, that we have the power to go against what our genes want us to do. He's not saying this is how morality should be, but that this is how natural selection works. And the second-to-last chapter, about the iterated prisoner's dilemma, is much more optimistic.)

"The Selfish Gene" is about biology, but I see the same depressing reality in recent human history. White Europeans came to America and killed most of the native people, and got away with it. And modern white Americans (including me) benefit from that. And the history books I read in school didn't really emphasize how bad and wrong it was. History is written by the winners, right?

Same thing with the Black Lives Matter movement. Ever since the days of Jim Crow, there have been murders of black people, and the murderers were never brought to justice. They got away with it, and white Americans can ignore it and get away with perpetuating the same racist system. There's no "higher authority" who's completely good and moral, who will listen to the evidence and judge with no bias. No, instead we have flawed people with subconscious biases at all levels of government. Just because you have innocence and truth on your side doesn't mean you're going to win. Power is what wins. (Related: I don't believe God answers prayer. Inequality is built into every part of our society. You think a world where God answers prayer would look like this?)

Man, that sucks.

As a Christian, I believe in resurrection. Someday God will right the wrongs. There will be justice. The world won't be like this forever. But still, there's this question: Why would God create a world where cruelty can succeed like that? Why would God create a world where the heartless process of natural selection is what led to the existence of humans? All of us exist only because our ancestors were good at protecting their own genes and screwing over other people. What good is it to say that innocent victims will be resurrected one day, if those innocent victims only existed in the first place because of the cruelty of natural selection? There can never be resurrection great enough to undo all the evil of natural selection, because our own bodies are the results of that evil. (The wheat and the tares grow up together, impossible to separate, amirite?) All those genes- the genes that are good at surviving, no matter the harm they cause to others- live in our bodies and make us who we are. If humans are made in the image of God, then what does that say about God?

I don't have an answer to that, and honestly, this is the problem that evolution presents for Christians. It really doesn't matter to me if the bible says God made the universe in 6 days but science says that's ridiculous- okay, yeah, then the bible was wrong about that. (Or rather, I believe that the biblical writers didn't actually mean it that way; it was in the genre of creation myths, not something that should be taken as a scientific truth.) I don't see that as a problem at all. I accept evolution as true. But that means that our entire existence and identity is built on the dead bodies of those who were taken advantage of, those who were too weak to protect themselves, the victims. How could God make a world like that? I don't know. It sucks.

One more thing I'd like to say: This book is about natural selection and evolution, but there was nothing in there that would come as a challenge for young-earth creationists (or at least, no challenge for the young-earth creationist who believes what Answers in Genesis has to say, as I did when I was a creationist). All of the examples in "The Selfish Gene" are what creationists would call "microevolution," which means there were some small changes in the species, but come on, those kind of changes could never create a completely new species. When the book does talk about "macroevolution"-type concepts, such as the question of how sexual reproduction came about in the first place, Dawkins presents some possibilites, worded in a very vague and generalized way, and makes it clear that we don't have any definite answers. Young-earth creationists love that.

In fact, young-earth creationists could make this claim: In the Garden of Eden, animals (or genes) did not behave selfishly. They were all nice to each other just because it was the right thing to do. (Indeed, Answers in Genesis claims that, before the Fall, all animals were vegetarians.) But after the Fall, when Adam and Eve sinned and screwed up the entire world, mutant "selfish" genes began to appear, and unfortunately, those genes are successful. That's when male animals began abandoning their offspring and lions began killing their step-children. It wasn't like that originally; no, God created everything good. But those genes spread, and now animals are cruel and selfish and all of nature has been going downhill since then. The "selfish gene" concept fits perfectly with young-earth creationism's belief that we live in a sinful world. No challenge there at all.

"The Selfish Gene" can be said to be depressing, but I don't think it has to be that way. It describes the world of biology as it is, but that doesn't mean we need to agree that it should be that way. We are capable of being more than our genes. We can work together, we can sacrifice to help others. Even though are genes only think its beneficial to help close relatives or those who can pay us back, we know better than that.

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