The Eye of Nature A Conversation with Richard Dawkins (Episode
Table of contents
- Unlock the secrets of our genes and the future of evolution with Richard Dawkins on the Making Sense podcast!
- Our genes are like a palimpsest, carrying the erased and rewritten stories of our ancestors' lives.
- We can't predict an animal's appearance just from its genes; the best way to see what an animal will look like is through its development process.
- Stretching for higher leaves won't make your kids taller—inheritance doesn't work like that.
- Nature's daily scrutiny perfects even the tiniest details for survival.
- Even the smallest evolutionary advantages can lead to significant changes over time.
- Humans have evolved to rely heavily on culture and technology for survival, making us fundamentally different from other species.
- Genetic engineering will soon let us customize humans just like we've bred dogs, and people will definitely embrace it for extreme aesthetics and performance.
- Our genes are like a colony of symbiotic viruses working together to ensure survival and reproduction.
Unlock the secrets of our genes and the future of evolution with Richard Dawkins on the Making Sense podcast!
Welcome to the Making Sense podcast. This is Sam Harris. Just a note to say that if you're hearing this, you're not currently on our subscriber feed and will only be hearing the first part of this conversation. In order to access full episodes of the Making Sense podcast, you'll need to subscribe at samharris.org. There, you'll also find our scholarship program where we offer free accounts to anyone who can't afford one. We don't run ads on the podcast, and therefore it's made possible entirely through the support of our subscribers. So if you enjoy what we're doing here, please consider becoming one.
Today's guest needs no introduction. Often one says that and then just gives the introduction anyway, but Richard Dawkins actually needs no introduction on this podcast, except to say that he has a new book titled The Genetic Book of the Dead. In the first part of the podcast, we speak about the genome as a kind of palimpsest, what scientists of the future may be able to do with our genetic information, genotypes and phenotypes, embryology, and epigenetics. We discuss why the Lamarckian theory of acquired characteristics just couldn't be true, how environmental selection pressure actually works, and why evolution is so hard to think about. We also cover human dependence on material culture, the future genetic enhancement of human beings, viral DNA, symbiotic bacteria, AI and the future of intellectual life, and the prospect of resurrecting extinct species.
Then we pivot to politics, discussing the problem of free speech in the UK, which has reached surprising proportions, as well as the problem of political Islam and anti-Semitism. We close with some reflections on our friend Dan Dennett. And now, I bring you the one and only Richard Dawkins.
I am here with Richard Dawkins. Richard, thanks for joining me again.
Great pleasure, Sam. Thank you.
So, you have a new book which, I'm sorry to say, I have not read in its entirety because I can only spend so much time reading a PDF that gets sent to me. I do not have the physical book yet, but I have read enough to declare that it is fascinating and that people should go out and buy it. So, we'll talk a little bit about it, but there are a few other things I want to talk to you about as well. But first, how are you and what is your life like these days? I think you and I had lunch about, I don't know, a couple of months ago.
Yes, we did.
Are you traveling or what's happening?
Yes, well, I'm doing a tour of most of North America at the moment, and then it carries on in Britain and Europe. I've said it's my final tour, and it's partly to promote the book. In fact, I suppose it's mostly to promote the book.
And how long are you on the road for?
Five weeks in North America and then an indefinite, well, a couple of weeks in Britain and Europe.
Nice. Well, needless to say, I hope it's not your final tour, or I hope that doesn't say anything about your longevity.
Yeah, I hope so too. My last tour might have been my final tour too, so you never know.
So, let's touch on the book. The title is The Genetic Book of the Dead. It's a reference you disavow early on. It produces an echo to the Egyptian books of the dead and the Tibetan. I would point out there's also Tibetan. It's just a kind of poetic allusion really. It doesn't really discuss those books. There's a kind of vague relevance in that I talk about genes as being immortal in the sense that they go on for generation after generation, whereas bodies are cast aside and die. So, the genes are a kind of set of instructions to the body, not to proceed to the afterlife as it would be in the Egyptian books of the dead, but to hand the genes on to the afterlife, which is the next generation and the next and the next.
Right. So, if we were going to take the analogy literally, and you also draw a similar analogy to a palimpsest, which you might describe what that is, but these are both analogies to books. We'll tell our listeners or remind them, not to be too pedantic, what a palimpsest is.
A palimpsest is a piece of writing which is partially or wholly erased so that you can write again on the same medium. In the days when there wasn't an abundant availability of paper, people would reuse the same parchment. They would erase what was already there and then write over it. I had a dear friend, Bill Hamilton, a very distinguished evolutionist, who wrote postcards where he would economize by writing in blue horizontally and then he would turn it...
Our genes are like a palimpsest, carrying the erased and rewritten stories of our ancestors' lives.
If we were to take the analogy literally, you also draw a similar analogy to a palimpsest. A palimpsest is a piece of writing that is partially or wholly erased so that you can write again on the same medium. In the days when there wasn't an abundant supply of paper, people would reuse the same parchment, erasing what was already there and then writing over it. I had a dear friend, Bill Hamilton, a very distinguished evolutionist, who economized by writing postcards in blue horizontally and then turning it to a right angle and writing in red, continuing the message. You could read it by deciphering the coding red and blue and the direction it was pointing.
You provide an example in the book, which I found difficult to read. It seemed like a provocation to one's friends to send them letters of that kind. I did manage to decipher it, and it was rather dramatic, involving someone getting his bike rammed. The genetic Book of the Dead is a description in the genes and the body of an animal of all its ancestral worlds. Natural selection has shaped the genes to survive in those worlds. Since its ancestors lived in many different worlds—very old, slightly old, and relatively recent—the genetic Book of the Dead is a palimpsest of writings from all these different ages, partially erased and written over again.
To come at it from another angle, if we could read the genetic Book of the Dead, we would read old writings about the sea when our ancestors lived there before the Devonian era. We would read about the emergence onto the land, subsequent history, and so on. In the case of primates, we would read about going up into the trees. Some animals went back into the water, which is remarkable, having adapted to land and then returning to the water. Turtles and tortoises, for example, came out of the water onto the land, back to the water as sea turtles, and then back to the land again as modern land tortoises.
I have a recurrent fantasy about a scientist of the future—I make her female and call her Sof—who will be able to read the book, which is the animal and its genes, and piece together the entire palimpsest of its ancestral history. This is something we can't do at the moment. Parts of the book are about the preliminary steps we can take towards that end. Given an unspecified genome, we are not very close to being able to predict the phenotype of the animal, which would be a big problem for the genetic Book of the Dead. Much of the book is about using the phenotype of an animal to reconstruct its set of ancestral histories. Sof in the future will be able to do this with the genes, something we can't do now. There is no decoding process whereby you can get a genotype and say what the ancestral worlds of this animal were.
We should probably remind people of the difference between a genotype and a phenotype. A genotype is the set of genes in the animal, while the phenotype is what the genes manifest as—the body, behavior, and everything we actually see of the animal. Given the genome, the series of base pairs in the nucleus of almost every cell in an animal's body, we currently cannot predict what that animal would look like.
We can't predict an animal's appearance just from its genes; the best way to see what an animal will look like is through its development process.
In the future, we may be able to decode ancestral histories using genes, but currently, we lack the capability to do so. There is no existing process that allows us to take a genotype and determine the ancestral world of an animal. A genotype is the set of genes in an animal, while a phenotype is how these genes manifest, encompassing the body, behavior, and everything observable about the animal. Given the genome, which is the series of base pairs in the nucleus of almost every cell in an animal's body, we cannot predict what the animal would look like. We are not close to achieving this capability.
What we can do is determine the exact proteins programmed by an animal's genome. However, the animal itself is produced through embryonic development processes, which are directed by these proteins. Unless we already know a lot about the animal, we can't reconstruct it from a genome alone. For instance, if we find a new genome and have no idea what kind of animal it is, we couldn't reconstruct it. But if we recognize it as a species of kangaroo, we can then work with it. The only way to truly find out what an unknown animal would develop into is to place the genome into a female of the species and let it develop.
Epigenetics is a term often misused and is essentially another word for embryology. Every cell in our bodies has the same genome, yet cells are different because some genes are turned on in certain cells and off in others. This differentiation is due to epigenetics. Recently, it has been suggested that some of these gene activations can be passed on to the next generation. This process has been shown in a few cases and has led to the word epigenetics being associated with this phenomenon, which has caused some confusion and overhype. Some people mistakenly think it resembles Lamarckian inheritance of acquired characteristics, which it does not.
Lamarck, who lived before Darwin, proposed a theory of evolution that was somewhat mystical. He believed that animals strive to change their way of life, such as a giraffe stretching its neck to reach higher leaves. He had two main principles: use and disuse (the more you use a part of your body, the bigger it gets) and inheritance of acquired characteristics (changes that occur during an animal's lifetime are inherited by its offspring). For example, a giraffe's offspring would inherit a slightly longer neck because the parent stretched its neck.
Stretching for higher leaves won't make your kids taller—inheritance doesn't work like that.
The giraffe's way of life involves striving to reach higher and higher leaves, which stretches its neck. This concept ties into two main principles: the principle of use and disuse, and the principle of inheritance of acquired characteristics. The principle of use and disuse suggests that the more you use a part of your body, the bigger it gets. For instance, the more you use certain muscles, the bigger they get, which is why people go to training. As the giraffe stretches its neck, everything about the neck stretches, embodying this principle.
The principle of inheritance of acquired characteristics posits that an animal inherits from its parents those changes which occur during the parents' lifetime. For example, the giraffe's babies would inherit a slightly longer neck because the parents stretched their necks. Similarly, if you exercise your muscles with weight lifting, your children would be born with slightly bigger muscles. However, this principle is false. While use and disuse happen, acquired characteristics are not inherited.
Modern science has introduced the concept of epigenetics, where certain genes get turned on during embryology. If this gene activation is passed on to the next generation, it represents a kind of inheritance of an acquired characteristic. However, this is very different from the giraffe's neck scenario and does not have the same adaptive potential. It does not pass on the improved capacity to survive to subsequent generations, making it evolutionarily irrelevant. Epigenetics works only for the next generation, not for the indefinite future, which is necessary for evolutionary relevance.
To clarify, an example of what could be transmitted from generation to generation through epigenetics might involve environmental stresses, such as the near genocide of a population or starvation. These stresses could change the epigenetic settings, altering the physiology of the children in some way. However, these changes would not extend to the grandchildren or great-grandchildren because they do not alter the germ line. They only change which members of the germ line get switched on, making it interesting but not evolutionarily significant.
It's important to understand why the Lamarckian theory doesn't work. Even if acquired characteristics were inherited, it would not be powerful enough to explain almost everything about evolution. For example, the development of an eye, which gets progressively better at focusing and providing more clarity and precision, does not happen through use and disuse. Darwin's principle, which states that nature is daily and hourly scrutinizing every detail, explains this better. Any tiny detail within an animal that improves its chance of survival can be passed on to the next generation and the next, perpetuating the improvement.
An illustrative example of this is camouflage in lizards and moths. The first picture in the book shows a lizard in the desert with patterns on its back that resemble sand, stones, and pebbles, providing camouflage. This daily and hourly scrutiny by the environment ensures that only those animals with the best camouflage survive and pass on their genes, demonstrating the continuous and meticulous process of natural selection.
Nature's daily scrutiny perfects even the tiniest details for survival.
The concept of evolutionary adaptation through natural selection can be illustrated vividly with the example of camouflage in lizards and moths. Darwin's phrase about the "daily and hourly scrutiny of the environment" encapsulates this idea beautifully. The first picture in the book features a lizard in the desert, with its back adorned with patterns resembling sand, stones, and pebbles, as if the desert is painted on its back. This is a classic example of camouflage, where the environment of the ancestors is effectively painted on the animal's back.
However, the thesis of the Genetic Book of the Dead suggests that this attention to detail is not merely skin-deep. It permeates every tiny detail of the animal, assisting in its survival. The daily and hourly scrutiny of the environment not only produces the picture of a desert on the lizard's back but also influences every minute detail inside the animal. Anything that aids in survival and the passing on of genes is subject to natural selection. Unlike the principle of use and disuse or the inheritance of acquired characteristics, Darwinism has the power to adjust to every single detail because if it assists survival, it gets passed on to the next generation and into the future.
To explain the incremental nature of this process, consider a moth that now looks exactly like the bark of a tree it habitually rests on. No moth could have evolved to look this way in a single generation. The process starts from an ancestor that looked hardly anything like the bark of a tree. Similarly, a modern stick caterpillar, which looks uncannily like a stick with little leaf bud scars, evolved from an ancestor that was just a vaguely long-shaped caterpillar.
The incremental process proceeds step by step. The final perfecting stages of resemblance are influenced by predators with full frontal vision in good light, paying full attention to the object. Early stages might have involved predators catching sight of the caterpillar out of the corner of their eye, in poor light, or from a long distance away. Even a crude resemblance to a stick can escape the notice of a predator under these conditions, providing the selection pressure to slightly improve the resemblance.
Just the slightest change in the probability of survival can encourage differential success. The gradient of improvement continues because there are predators observing caterpillars at various distances and under different seeing conditions. The selection pressure produces the initial stages of mimicry improvement, while the final stages are refined by predators looking directly at the caterpillar in good light, still being fooled by the perfect resemblance.
This process is an amazingly beautiful demonstration of natural selection. Understanding it intuitively can be challenging, but it reveals the intricate and gradual nature of evolutionary adaptation.
Even the smallest evolutionary advantages can lead to significant changes over time.
A poor resemblance is good enough to fool a predator at 100 yards away. However, at 90 yards away, the resemblance has to be slightly better. Predators observe caterpillars from various distances and under poor seeing conditions. This selection pressure produces the first stages in the gradient of improvement to the mimicry. The last stages are provided by predators that are looking straight at the caterpillar in good light and are still fooled by it because the resemblance is so perfect. This process is amazingly beautiful to think about.
Understanding this intuitively is challenging. One reason is the huge time scale involved in evolution. We are not equipped to deal with millions, let alone hundreds of millions of years. Sometimes, the time scale can be surprisingly compressed and short, especially in the case of the evolution of mimicry, which could be quite fast. However, this presents its own impediment. If the time scale is too short, it seems like there's not enough time to accomplish the changes. If it's too long, it's very hard to conceptualize. There's no sweet spot, although it might vary in different cases, ranging from 100,000 years to a million years.
Another barrier to understanding evolution is that people don't realize that a very slight advantage is enough to exert evolutionary change. For example, consider the function of eyebrows. Suppose eyebrows exist to stop sweat from trickling into our eyes. While it might seem insignificant, if sweat trickling into your eyes affects your ability to see a predator, it could impact survival. The statistical frequencies of genes change over generations, and any gene that tends to make eyebrows stop sweat from trickling into your eyes has a cumulative beneficial effect over many individuals and generations. This slight advantage is enough to drive evolutionary change, even though it might seem counterintuitive.
Human beings seem imperfectly selected to survive without material culture. David Deutsch has pointed out that the Earth is essentially a spaceship for us. Without the benefits of shelter, clothing, or fire, humans are likely to die of hypothermia, even in relatively mild climates like Oxford. We are naked apes that are not great at survival apart from being in tribal bands that produce and pass on material culture. Each representative of the species, devoid of culture, placed on a desert island, is liable to die within a short period because of being fundamentally unable to survive against raw nature.
Humans have evolved to rely heavily on culture and technology for survival, making us fundamentally different from other species.
Essentially, a spaceship for us, right? If you just leave a human exposed, even to an Oxford KN, without the benefit of shelter, clothing, or fire, he is likely to die of hypothermia on many nights of the year. We are these naked apes that are not great at survival apart from being in tribal bands who have produced a monom of material culture and an ability to pass on that culture to subsequent generations. Each representative of the species, devoid of culture, put on a desert island, is liable to die over the course of 72 hours or a week because of being fundamentally unable to survive when slammed up against raw nature.
What do you make of the difference between human beings and basically everything else we see in the living world? If you were to go back to our time when we lived for such a long time in Africa, in the savannah, we would have been a lot better at surviving as individuals. Even then, we would have needed culture, but nothing like so much as we do today. Now, we have supermarkets, we get our food prepared for us, we don't have to go and get it, hunt it, kill it, or gather it. We just go into a shop and buy it. We are mollycoddled by electricity and central heating. If you were to take a modern American or Englishman and expose him to the elements, he might die. However, if you were to do the same with a Kung San from the Kalahari Desert or an Australian native in the Australian Outback, they would do pretty well.
We have co-evolved culturally and genetically, gradually emancipating ourselves. Our genes have moved us into a world surrounded by culture, which has been evolving at a very rapid rate. We have become dependent upon this culture, which includes wearing clothes, taming fire, central heating, and cooperative living. Farmers grow food for us, so we don't have to grow it ourselves. This co-evolution with culture and technology is not difficult to understand.
What are you expecting us to do with our increasing power to engineer changes within our own genomes? If you had a time machine and could glimpse what we're up to on that front 50 or 100 years from now, what would you expect? We have been changing the genomes of domestic animals and plants for thousands of years, very radically. Domestic animals like cattle, horses, pigs, chickens, and pets like dogs are incredibly different from their wild ancestors. This has been achieved by artificial selection, not by direct manipulation of genes. For example, pines and chihuahuas are genetically wolves that have been modified by differential selection by humans.
Now, you're asking about the other part of the Darwinian equation, which is mutation. We have shown we can modify animals by selection, but we've never done that with humans. The Nazis tried, and thank goodness they didn't succeed. One could imagine that in thousands of years, if totalitarian regimes started selecting humans the way we've selected dogs and cabbages, you could produce all sorts of monstrous humans, analogous to producing chihuahuas from wolves.
However, to go into the genome of a hedgehog, for example, and change the genes to make it a high jumper is in principle possible but would take much more knowledge than we have at present. Selective breeding could gradually improve the jumping ability of a hedgehog, just as dogs have been bred from wolves into various breeds. But to directly manipulate the genome for such a trait requires a level of understanding we currently do not possess.
Genetic engineering will soon let us customize humans just like we've bred dogs, and people will definitely embrace it for extreme aesthetics and performance.
If you wanted to produce an animal, not just as a human, say you wanted to produce a hedgehog that could do the high jump and jump impressively high fences, in principle, you could do it. You could achieve this through selective breeding, although it would take a while. There's no reason you shouldn't gradually improve the jumping ability of a hedgehog until it could jump a foot, then two feet, and so on, just the way dogs have been bred to change from wolves into Pomeranians and Spaniels. However, to go into the genome of a hedgehog and change the genes to make it a high jumper is in principle possible but would require much more knowledge than we currently have.
The same applies to humans. If we keep making progress, we will eventually understand the relevant genomes and the technology to intrude into our own genomes. We already have CRISPR, and presumably, it will only get better and better understood in terms of its implications for making genetic changes. There is already an appetite for body modification and general strangeness among humans. We see people who tattoo their entire bodies and bodybuilders who develop their musculature to the absolute maximum capacity, often with the aid of pharmacology that compromises their physical health. This also happens among athletes, indicating a clear appetite for extreme performance and aesthetics, even if it degrades performance.
Once we have the ability to modify tendons, ligaments, and muscles to make a person as strong as a gorilla or a chimpanzee, there is little doubt that people will start doing that as soon as the technology becomes democratized. People do the most extraordinary things, and I believe they would take advantage of such opportunities. Although we haven't changed humans by selection the way we've changed dogs, genetic manipulation could achieve similar results much quicker. Bodybuilders already show what can be done through various forms of manipulation, and genetic manipulation could be even more powerful.
It's possible to imagine producing musical geniuses like another Mozart or Beethoven through genetic means, which is a tantalizing thought. However, I spend much more time thinking about the implications of artificial intelligence with respect to this kind of time horizon. When considering genetic engineering, it's hard to imagine what would prevent us from going some significant distance down this path. There are concerns about synthetic biology, engineered pandemics, and ethical concerns related to eugenics and totalitarian control of populations. Yet, as the technology becomes more available to individual users, similar to how drugs are available now, it's hard to imagine us avoiding extreme outcomes on a global level.
Is there anything else in the book that you want to draw attention to in terms of your purpose in writing it or what was most interesting to you in researching?
Our genes are like a colony of symbiotic viruses working together to ensure survival and reproduction.
Eugenics and totalitarian control of populations are concerning topics. However, when we consider the increasing availability of technology to individual users, much like how drugs—both legal and otherwise—are accessible today, it becomes challenging to envision a scenario where we can culturally collaborate to avoid extreme outcomes on a global level. For instance, anabolic steroids in bodybuilding serve as an example of this accessibility. It’s very hard to imagine us avoiding these issues perfectly.
In discussing his book, the author highlights a significant point in the last chapter, suggesting that we should view our genes as a gigantic colony of symbiotic viruses. This idea is not as radical as it sounds. It doesn’t imply that independent viruses like the flu or COVID-19 came together in us. Instead, it makes a distinction between parasites or symbiotic organisms, like viruses or bacteria, that pass through the gametes—sperms and eggs—of the host.
Consider a bacterium or virus that transmits from human to human via eggs or sperms. Such organisms share the same interests as the host’s genes: they want the host to survive, reproduce, be sexually attractive, and be a good parent. This cooperation is essential because it ensures their passage into the future. Natural selection favors selfish genes that can secure their future. Similarly, a virus that transmits through sneezing, coughing, or other means does not share these interests. These viruses might only need the host to survive long enough to spread to the next victim.
The provocative analogy here is that our genes can be thought of as viruses with the same interests at heart. All our genes cooperate to ensure their passage through sperms or eggs into the future. Thus, distinguishing between viruses that transmit this way and our own genes becomes unnecessary. They might as well all be called viruses or genes.
This analogy is further supported by the fact that 8% of our genome is believed to have come from separate viral origins. To continue listening to this conversation, you can subscribe at samharris.org. The Making Sense podcast is ad-free and relies entirely on listener support. If you can't afford a subscription, you can request a free account through their scholarship program.