How Charles Darwin Changed The World

Chapters:

01:42 The Intellectual Climate of Darwin's Time
07:10 Darwin's Early Life and Influences
10:47 The Voyage of the Beagle
16:48 Understanding Natural Selection
26:45 Darwin's Contributions to Geology
31:55 Nature vs. Nurture Debate
39:52 The Controversial Reception of Darwin's Theory
42:09 The Descent of Man and Its Implications
47:19 The Church's Acceptance of Evolution
50:05 The Importance of Earthworms
53:40 Darwin's Daily Life and Productivity
56:14 Cultivating Observational Skills
60:13 Setting the Record Straight on Wallace
63:57 Wallace's Contributions to Science
68:05 Advice for Graduate Students

The Intellectual Climate of Darwin's Time

Keith Yap 01:42

Perhaps it might be useful to first understand the dominant intellectual climate pre-Darwin. How did people think about the origins of species back then?

John Van Whye 01:53

It's not like what you usually hear in media or documentaries that before Darwin, everyone thought God just made all species in seven days. The sciences were already quite advanced, especially geology and paleontology. They knew about the fossil record well - that millions of species had appeared and disappeared repeatedly.

Everyone accepted this. They just didn't accept that species had evolved from one another. They thought there had been lots of separate creations. When new islands arose in the ocean, somehow new species were created to live there. People started to think that maybe God creates species through natural means, just like mountains arise and fall naturally, and planets move according to natural laws.

No one doubted God's involvement, but they wondered if it might be indirect, through natural laws like many other phenomena. That was the state of thought just before Darwin. When you look at it this way, it's not that radically shocking. The scientific community already knew living things had come and gone millions of times - they just really didn't like the idea of evolution.

What Darwin did was convince them that evolution was real and ongoing.

Keith Yap 03:47

Why weren't they welcoming to the idea of evolution?

John Van Whye 03:52

There are two main reasons. First, they really wanted God to be actively involved and intervening in nature, creating butterflies and other creatures. Second, and more significantly, in some parts of the world people really hated the idea that humans could have come from animals.

Interestingly, from a global perspective, peoples who lived in regions with apes and monkeys historically had no problem with the idea of human beings coming from apes. Those living in parts of the world without these animals tended to be very offended by it.

Throughout Africa and Asia, traditional communities familiar with these animals often had folklore and traditions connecting humans and primates. Some believed they came from apes, while others believed apes and monkeys were humans who had gone into the forest and degenerated. So the Darwinian idea wasn't as shocking to these cultures.

Keith Yap 05:23

That reminds me of Journey to the West, the classic Chinese tale with the Monkey King who is anthropomorphized. There was already that familiarity with humans and monkeys being similar. If we think about Darwin's Origin of Species and his theory of evolution, what did he specifically posit that fundamentally reshaped how we think about ourselves?

Darwin's Early Life and Influences

Keith Yap 07:10

You're the world's leading expert on Charles Darwin and have this comprehensive web archive online, Darwin Online, collecting all his works. What experiences molded him when he was young that set him on this path of being what we would call a scientist today?

John Van Whye 07:27

He realized he had an innate interest in nature and liked collecting things, whereas his siblings who grew up in the same household weren't interested in these things. When he went to university, he got into what we would call biology, though you couldn't actually study it formally back then - there were no science degrees yet.

There were already people very advanced in studying plants and animals, so he immediately pursued this and became very proficient. Initially, the plan was for him to become either a doctor or a man of the church. But even if he had taken either path, he still would have devoted his life to science, as did his cousin who joined the church but spent his life working on science. That was really common back then.

It was his personal interest and passion. When someone has passion for a subject, they can go really far. If you just have to do it, it's hard to motivate yourself.

Keith Yap 08:37

Do you think there was an obsession?

John Van Whye 08:38

Absolutely, obsession is a fair word to use. For example, when he was a student in Cambridge collecting beetles, he was competing with fellow undergraduates to get the best collection and find the really rare ones. One day he saw an extremely rare beetle and grabbed it. Right next to it was another super rare one, so he got that too. His hands were full when he spotted a third incredibly rare one.

Not wanting to let any go, he popped one in his mouth to free up a hand for the third beetle. The one he put in his mouth had a defense mechanism and shot some kind of acid into his throat. He coughed it out and lost all three beetles in the chaos. That's somebody with passion for collecting and their hobby.

Keith Yap 09:33

What at Cambridge encouraged him to pursue this path? Was it the academic environment that shaped him?

John Van Whye 09:48

I think it's really like it is today. There were the required academic studies to graduate, but also many other opportunities if you were interested. For three years in a row, he took Professor Henslow's botany lectures. He really admired Henslow, who seemed to know everything, and Darwin became quite close with him, learning a lot about science.

As a young man, he was aware of all the books and articles being written on science and the things he was passionate about. He knew there was a world he could move into, and now he had his foot in the door at university by meeting some of the major figures. That was really exciting - although he was a beginner, he was welcomed. And that was just the beginning.

The Voyage of the Beagle

Keith Yap 10:47

Following which he went on the voyage of the Beagle. That was where we started to see Darwin come into his own. Could you help us understand how this journey shaped his thinking that would eventually lead to Origin of Species?

John Van Whye 11:11

The Beagle, which was named after a type of dog, was assigned by the Royal Navy to circumnavigate South America and then the world to make more accurate maps than existed already. Their maps were so good they remained in use for over a hundred years. They found every submerged rock and documented everything meticulously.

The captain thought it would be good to take along a naturalist to study the nature of all the remote places they would visit. Darwin turned out to be that person, and he was remarkably well qualified. He had just graduated from university, had studied sea creatures at Edinburgh, and was proficient in botany, insects, shooting, and geology. He had the experience and competence to study everything from microscopic sea creatures to giant fossils.

Over five years, he uncovered extinct fossil creatures in South America and saw bizarre living things around the world. By the time he returned, he had experienced what few people who have ever lived could match in terms of witnessing and examining life on Earth. But among his collections were many puzzling discoveries - things that didn't make sense, like sea creatures living on land in forests, flightless birds with wings, and birds with webbed feet that never touched water.

The fossil bones he discovered in South America were related to animals that only live there today. Why should that be? Is there something about South America that makes armadillo-like creatures appear there? Similar patterns were found with extinct kangaroos in Australia. All these puzzles, including his observations of the Galapagos Islands, led him to question the origin of species.

The Galapagos had erupted from the sea as lava - nothing lived there initially. Yet when he visited, there were many plants and animals. Where did they come from? The earlier theory would have said they were created or somehow formed from nothing. But Darwin realized this couldn't be true - the creatures there looked similar to those in nearby South America, yet they were distinct species.

This led him to conclude they must have descended from South American species and changed over time. This explanation made sense of the whole fossil record - different species through time gradually looking different because they descended from one another, with many extinctions and dead ends along the way.

Understanding Natural Selection

Keith Yap 16:48

Many tangents to explore here, but it might be useful to understand the process we call natural selection. Darwin's theory was that there was a kind of natural selection at play. If we were to dissect the term "natural selection," what does it actually mean?

John Van Whye 17:10

This has been endlessly confusing since Darwin published the phrase "natural selection." It's an analogy with what farmers and breeders do when they select which animals to breed and which to eat. For example, if you keep chickens for egg production, some birds lay six eggs a week while others lay four. You choose to breed from the better egg-layers.

By selecting, farmers and breeders actually change living things. They modify sheep, peas, or whatever they work with by selecting which features continue and which don't - more eggs, more fat in meat, and so on. Darwin's natural selection means the same process happens in nature, but without a farmer or breeder selecting. In nature, it's simply survival versus death.

This is the confusing part for many people - nothing is deciding, and there isn't a force or power in nature called natural selection. Even great biologists make this mistake by referring to natural selection as a force doing something. When explaining to people who don't understand how it works, it's not helpful to perpetuate this myth. Natural selection is Darwin's name for whatever in the world makes a difference between living and dying.

That encompasses many things - drought, starvation, disease, predators, or even being the wrong color. If you're a bug living in a brown environment and you're born too green, you're likely to be seen and eaten. All these factors are called natural selection. It's not really a thing - it's just a convenient label.

Another useful metaphor is a filter. The process of natural selection is like a filter - lots of things are born, like all the pollen in the air, but most never make it through the filter of death. They die without leaving descendants. Every generation, new variations are born, and they either pass through or get blocked by that filter.

When you see organisms staying the same, that's natural selection too. People often think evolution only means dramatic changes, like giraffes' necks getting longer. But maintaining stability is also evolution - if variants that differ from the norm don't survive, the species remains unchanged. It's all about what gets through the filter of death. Are they fast enough? The right color? If so, they survive. If not, they don't.

This constant filtering either maintains stability or allows gradual change in new directions. There's nothing in control - just this filter of survival.

Keith Yap 22:02

How then do we make sense of random mutations that we see in the natural world every day?

John Van Whye 22:08

Mutations happen constantly due to cellular and molecular complexities. They're extremely common - my students are often surprised to learn that most people they know are probably mutants. The X-Men films make a big mistake when they distinguish between mutants and humans. That's nonsense - it doesn't work that way.

A single mutation doesn't create a new species. That process would take hundreds of thousands of years of continuous change. Mutations happen every second worldwide, but most are so tiny they go unnoticed. Usually, they make no difference because they're minimal and random.

Mutations occur in every possible direction. The filter I mentioned either prevents survival if a mutation is too different or unhelpful, or allows survival if the mutation happens to be beneficial. For example, if beetles live on brown rocks, those born with poor camouflage won't survive. But if one is born with better matching coloration, it's more likely to survive.

When we see insects perfectly matching their background, appearing almost invisible, this is how it happened. Because tiny variations, including mutations, happen continuously, there's always variation that could move in different directions if survival allows it.

Keith Yap 24:13

And as long as they survive, these traits propagate?

John Van Whye 24:18

It's all probabilistic and relative. The old phrase "survival of the fittest" isn't a good shorthand for Darwin's theory because sometimes it's survival of the slowest or the stupidest - it's relative to the environment. Sometimes organisms become simpler rather than more complex, like cave fish losing their eyes.

Fish with eyes swimming in the sea are advanced organisms with excellent vision. But when fish end up underground and live there for thousands of years in darkness, occasional eyeless variants have an advantage because eyes are costly organs to maintain. They require significant energy and resources to grow and maintain, yet provide no benefit in darkness.

So when an eyeless fish is born in a cave community, it has an advantage over its eyed companions. It's likely to survive better and have more offspring. This has happened independently many times worldwide - whenever we find fish in caves, they tend to lack eyes. That's how evolution works.

Darwin's Contributions to Geology

Keith Yap 26:45

You noted that he was an excellent geologist as well. What kind of work did he do on his voyages that helped us understand how the world was formed?

John Van Whye 26:59

It's often forgotten today that he was one of the world's leading geologists. Fresh from university on his voyage, he had amazing opportunities. He discovered that southern South America had been repeatedly elevated from the sea over millions of years.

You can see this at the shoreline - there's a beach where waves have rounded stones over thousands of years. Inland, he found plateaus with similar rounded stones - remains of ancient beaches now elevated hundreds of feet up. Step after step showed the land had been repeatedly elevated, with long periods of sea erosion between.

This gave him continental-scale evidence of how Earth's surface gradually changes. In the Pacific, he studied coral atolls - islands made entirely of coral rock. These ring-shaped islands were mysterious - how did they form? Coral can only live in shallow, sunlit water, yet the ocean floor might be a mile deep.

The previous theory suggested underwater volcanoes had erupted and died just below the surface, allowing coral to grow on top. But Darwin thought it implausible that so many volcanoes would stop at exactly the right depth. In Tahiti, seeing an island with its surrounding reef, he realized that if the volcanic island gradually sank over millions of years while the reef grew upward, you'd eventually have just a ring of coral - an atoll.

After World War II, when testing atomic bombs in the Pacific, they drilled through these coral islands and found volcanic rock more than 5,000 feet down - proving Darwin right. The seafloor was gradually sinking while coral growth maintained the reef's position. It's an amazing discovery for someone in their mid-twenties, and eerily similar to his theory of life's evolution - tiny, gradual changes accumulating over vast time periods to create enormous change.

Nature vs. Nurture Debate

Keith Yap 31:55

There's an age-old debate over nature versus nurture, or how much nature impacts the way we evolve or adapt as human beings. Can you help me understand how Darwin approached this nature versus nurture discussion?

John Van Whye 32:13

Three young people from Tierra del Fuego had been taken back to England, taught English, and introduced to Christianity. The plan was to return them home to spread these influences and establish friendly contacts for future shipwrecked sailors. What shocked Darwin was seeing their homeland - so wild and remote, thousands of miles from any cities, where people had lived for thousands of years in simple shelters, walking almost naked with animal grease on their skin.

When they left these westernized individuals behind and returned weeks later, they had reverted to local customs - nearly naked again, their hair unkempt, their polished shoes and clothes gone. This shocked Darwin by showing him that what everyone back home considered civilization was just a thin veneer.

We fool ourselves by surrounding ourselves with civilization, thinking we're so different and have left nature behind. But it hasn't gone anywhere - it's right there. These people had shed the trappings of civilization when necessary to survive in their harsh environment. One way of living works in a city, but something very different is needed when living on frozen, windswept tundra.

The Controversial Reception of Darwin's Theory

Keith Yap 39:52

So the thin line between humans and animals was apparent to Darwin. It must have motivated his work in Origin of Species - it would have been more intuitive to him. When he published his work, what was the reception like? I'm sure the blowback was serious in some cases, though we take his work for granted now.

John Van Whye 40:56

The book was hugely controversial when it came out in 1859. Everyone had heard of some kind of evolution before, as many thinkers had proposed changes in plants and animals. But Darwin's version was different -it had a single branching family tree through the process of selection, without any invisible natural law pushing it in a particular direction.

It was very plausible, but people had a long-standing tradition of viewing evolution as unserious science - popular science junk. Some people immediately saw this version was different and had to be taken seriously. Others continued treating it like previous evolutionary theories and mocked it.

Within 15 or 20 years, the fight was over, which surprises my students nowadays. People stopped fighting over evolution, and it's been established scientific fact ever since. How did he convert a world that hated the idea of evolution and thought it couldn't be true? I think it was because he wasn't attacking people's beliefs - he was just explaining how things work. Their religious beliefs, particularly, didn't need to be affected. Most people carried on with their religion while accepting his scientific explanation.

The Descent of Man and Its Implications

Keith Yap 42:09

How did he convert these thinkers bit by bit? What was the narrative that eventually led to this conclusion that we came from a common ancestor?

John Van Whye 42:27

He made his case for evolution in general in Origin of Species. Everyone talked about its implications for human beings, though the first book wasn't about that - it was about the general process of how living things change over time and how they're related.

Twelve years later, he published The Descent of Man, specifically addressing human evolution. The controversy erupted again, and that's when the caricatures of Darwin as an ape-man began appearing. His case was powerful - he showed that anatomically, there is no difference between us and other primates. Given that everything else had gradually changed from similar forms, and there was nothing physically distinct about us from other living things, we clearly had to come from the same family of animals.

It was very shocking and objectionable for some people, but by this time, the evidence was overwhelming.

The Church's Acceptance of Evolution

Keith Yap 47:19

Why did the church come around within a few years?

John Van Whye 47:23

The church came around because of their particular type of Christianity, where the Bible stories had never been something people were sworn to believe literally. The Bible was their source of knowledge, but more importantly, it was a source of faith. Their religion was about faith and belief - whether Noah's ark and the flood really happened made no difference to believing in God and believing you would go to heaven.

When geologists, most of them Christians and many in the church, found there was never a global flood, it wasn't a deal-breaker because that's not how their religion worked. They weren't dedicated to believing Bible stories were literally true. The same happened with astronomy showing Earth wasn't the center of the solar system, and geology showing the world wasn't created 6,000 years ago.

Darwin was the last in a long series of such discoveries. Humans descended from apes? They could still believe God had given people a soul, and the rest of their religion carried on the same. That's why it didn't really matter that some Bible stories weren't literally true - that was never the point of their version of Christianity.

The Importance of Earthworms

Keith Yap 50:05

Charles Darwin spent over 30 years writing a book on earthworms - his last publication. That seems odd. You write about the Origin of Species, talk about the descent of man, and then earthworms. Why were earthworms so important?

John Van Whye 50:24

It took 30 years from first noticing worms' importance in shaping the landscape to publishing the book. This was typical of how Darwin worked - he would notice something and then take time to fully investigate it.

He observed that when material was scattered on a field, it gradually vanished underground. This was due to earthworms - they dig tunnels, take material into their mouths, come to the surface, and deposit it in small coils, like squeezed toothpaste. Multiply this by billions of actions over every hectare, and material is constantly being moved from underground to the surface. Anything too large for a worm's mouth stays put and gets buried as they undermine what's beneath.

This is how many archaeological ruins end up underground. Darwin experimented by placing a stone in his garden and measuring how it slowly sank. Just like his coral reef theory and natural selection theory, tiny actions that seem mundane become significant when multiplied over time.

His book showed that worms weren't pests as people thought - they were essential. They eat rotting leaves and their tunnels prevent soil from becoming too compacted. Without them, growing crops would be impossible. Civilization depends on these mundane little creatures. Showing how small changes can create huge effects - that's pure Darwin.

Darwin's Daily Life and Productivity

Keith Yap 53:40

When you talk about the Darwinian idea that little things add up - in his life he was incredibly productive, but at the same time he was grappling with illness and his day-to-day life seemed quite boring and mundane. What was his daily routine actually like?

John Van Whye 54:00

As a wealthy man and father of a large family, he had the freedom to choose his routine. He moved from smoky, polluted London to a quiet, beautiful village in Kent. His daily schedule was precise - early rising, tea, a walk in the woods, work in his study, family time by the fire, reading letters, having novels read to him, and napping after lunch.

Every day followed exactly the same rhythm. Without normal job commitments, the family worked according to this routine. That's what he was comfortable with. Even other people at the time thought his life seemed boring, like clockwork - but some people find comfort in such consistency.

Cultivating Observational Skills

Keith Yap 56:14

What about his observational skills? How does one cultivate that kind of observational ability?

John Van Whye 56:27

Darwin once said about himself, "I don't think I'm more intelligent than the average person. If there's one thing I have, it's the ability to notice things that other people don't." That's pretty accurate. He noticed things others missed, like the relationship between fossils and living animals in South America.

Part of this ability is innate - some people just notice things others would never see. But you can cultivate it through inspiration and guidance. I've taken Singaporean students from urban backgrounds into Southeast Asian forests. By repeatedly showing them what to look for - under leaves, away from the trail - you start to open their eyes to things they're missing.

I've seen people walk past tree snakes and even cobras without noticing them. You need to be shown, or inspired, to look closer because there are all kinds of things we're not seeing. When we do see them, it's amazing.

Setting the Record Straight on Wallace

Keith Yap 60:13

There was a contemporary of Darwin - Wallace. There's been this idea that he was a rival or somehow overlooked. Can you help us set the record straight?

John Van Whye 60:23

I've spent a lot of time setting the record straight. As a historian of science, I've done more research and published more books and articles on Wallace than any other historian. Although people think of me as a Darwin person, I'm more of a Wallace person than any other historian.

Wallace is a fantastic person with an interesting story. Unfortunately, in the middle of the 20th century, his story began to be retold and progressively depart from historical reality. If you read a book about Wallace from before 1960, everything in it will be accurate. After that, it's almost certain to have myths emphasizing how he was forgotten, mistreated, or cheated.

These stories about feeling sorry for Wallace sell better than the truth. Nothing nefarious happened between Wallace and Darwin in their lifetimes or for a generation after. Their parallel discovery of evolution was considered a remarkable coincidence and a happy ending until the middle of the 20th century. Since then, it's been portrayed as something sinister.

Wallace's Contributions to Science

Keith Yap 63:57

What were Wallace's scientific contributions in understanding our world? He was immersed in Southeast Asia at one point in his career and did so much. He even had Ali Wallace assisting him. Help us understand how Wallace pushed the envelope of science.

John Van Whye 64:21

Wallace came to Southeast Asia as a collector. With few science jobs available and no family money, he needed to earn a living. He loved nature and science, so becoming a self-employed collector was perfect. He traveled throughout Southeast Asia for eight years, employing many local people, with Ali being his most important and longest-serving assistant.

Wallace and his assistants collected an enormous number of specimens - beetles, butterflies, birds, and small mammals. This vastly increased scientific knowledge about life in this huge region. We don't even know how many species he discovered - probably hundreds of things known to science came from Wallace's work.

He paid particular attention to species distribution - which creatures lived where. Every island had different combinations of species. He documented all this because it helped reconstruct life's past. His biggest discovery was what we now call the Wallace Line - an invisible boundary running through the region, most notably between Bali and Lombok. In Bali, you find Asian types of animals, while Lombok has Australian families of birds and other animals.

This dramatic difference in animal types, despite the islands looking similar, suggested these species weren't created there but had come from somewhere else. In the midst of this work, he developed his own version of evolution by natural selection. By the time he returned home, his collecting had earned him enough to live as a Victorian gentleman.

His association with Darwin was beneficial - Darwin's book had come out while Wallace was still in Southeast Asia. Darwin's twenty years of work had convinced the world that evolution was true. Wallace had discovered the same filtering process, though there were many other parts of Darwin's theory he hadn't yet considered. When Wallace returned, he was already associated with this scientific revolution.

Advice for Graduate Students

Keith Yap 68:05

My last question for you: What is that one piece of advice that you always give to your graduate students?

John Van Whye 68:11

I think I give lots of pieces of advice. One would be to pursue your passion and interest, even if it's not fashionable. It may not be what everyone else thinks is hot and interesting right now, but if you follow what really interests you, you might go really far.

Keith Yap 68:35

With that, thank you, Prof, for coming on.

John Van Whye 68:37

You're welcome. Thanks for having me.