The theory of evolution has evolved over many generations. Understanding its history helps in understanding its application in the present. This is an excerpt from the book Philosophy for Heroes: Continuum and the book Does The Brain Need You? If you want to discuss these subjects, check out the Philosophy Meetup Group or follow me on social media (see the bottom of the page).
It makes one wonder what the evolutionary tree of this idea [the theory of evolution] would look like, were it an organism that could be mapped out by fossil record rather than words. The concept is one that faded nearly into obscurity, only now to be revived with slight mutation. What I personally gather from this is that survival of ideas depends less on the actual quality of the idea, but rather the climate into which it is introduced. Quite literally, survival of the fittest, but not necessarily the best.Aquinas and Evolution [fortunesfool, 2007]
Evolution itself still evolves by adding more abstraction layers to it (for example, DNA, multicellularity, sexual reproduction), by creating conditions for faster evolutionary processes within an organism (immune systems, the mind) and finally by having such an organism recreate new artificial organisms based on these principles (artificial life). Each of those evolutions of evolution leads to more complex organisms on Earth.
Significant steps along this path include:
- 3.8 billion years ago: Earth cools down, meteoroid bombardment ends, first protocells with RNA appear, deep sea hydrothermal vents provide basic metabolism for protocells.
- 2.45 billion years ago: Cells produce oxygen toxic to most other existing bacteria, massive climate shift, photosynthesis begins (Great Oxidation Event).
- 2 billion years ago: Specialized cells appear, genotype / phenotype differentiation begins, cell machinery separates into DNA, RNA, lipids, and proteins.
- 1.5 billion years ago: Multicellular organisms appear.
- 1.2 billion years ago: Sexual reproduction and crossing over of DNA speed up evolution.
- 500 million years ago: Adaptive immune systems based on an evolutionary algorithm appear, first animals appear.
- 220 million years ago: Mammals appear.
- 100 million years ago: Primates appear.
- 65 million years ago: Asteroid collides with Earth (CretaceousPaleogene extinction event), climate shifts, dinosaurs become mostly extinct, rise of the mammals begins.
- 8 million years ago: Last common ancestor of humans, chimpanzees, and gorillas disappears.
- 2.5 million years ago: Humans appear.
- 300,000 years ago: Modern humans with a “Darwin machine” (see Calvin , a high-speed evolutionary algorithm) in the brain appear.
- 70,000 years ago: Writing is invented.
- 2,000 years ago: First mechanical computer for astronomy (Antikythera mechanism) is developed.
- 1,000 years ago: Scientific method is developed.
- 1543: Scientific Revolution begins.
- 1859: Theory of evolution is published.
- about 100 years ago: Theory of relativity and quantum theory are published.
- 1950s: Theory of DNA is published, digital computer is developed, cellular automata, and evolutionary algorithms are used for the first time on the computer.
- 1960s: First human lands on the Moon, development of the Internet starts.
- 1970s: Theory of adaptive immune systems and theory of memes are published.
- 1980s: Theory of neural Darwinism is published.
- 1990s: Artificial life is created on the computer, World Wide Web is launched.
Coming back from this bird’s eye perspective to the ground, when people think about the theory of evolution, it is typically Charles Darwin who comes to mind—he is celebrated as the one who came up with a revolutionary idea. But people tend to remember only the first (or last) participants in a long series of events. For example, take the first humans on the moon: Neil Armstrong and Buzz Aldrin are well known, but who remembers the person staying in orbit, Michael Collins?
Michael Collins was the third person on the Apollo 11 mission, remaining in orbit while Armstrong and Aldrin descended onto the moon. The mission would have been impossible without him, just as the mission would have been impossible without the people building the moon lander, the computers, and the rocket, or the people managing the operation on the ground. “Heroes” would not have been able to land on the moon and successfully return. The operation was too complex to be achieved with a singular heroic effort; thousands of things had to be just right. Sure, the astronauts were risking their lives, but so did the people on the ground, every day they drove to work.
Collins feared that something would happen and that he would be the only one to return, with the spotlight on him, then being “a marked man.” In a recent interview, at the age 78, he said that he is bothered by today’s inflation of heroism and adulation of celebrities, adding that he is no hero and that “heroes abound, but don’t count astronauts among them. We worked very hard, we did our jobs to near perfection, but that is what we had been hired to do.”
Learning about the complexity of the moon landing relativizes the role of the astronauts, just like learning about the centuries-long evolution of the theory that Darwin made famous relativizes his role. Neither the moon landing nor the theory of evolution is the result of magic or a singular heroic effort. Each can be understood by looking at the whole chain of industry, of scientists, and of ideas.
We are often taught only about the last element of a long chain of events. And those not familiar with a subject see this last element as almost supernatural. In science, it is easy to overlook how theories were developed over centuries. This applies to the theory of evolution, which is difficult to understand if one simply jumps over thousands of years of scientific progress and focuses only on the final result.
In ancient times, during Homer’s era (ca. 750 BC), life was understood as the result of the action of whimsical, inconsistent gods. In this world, the rather primitive statement by Thales (626–548 BC), “The first principle and basic nature of all things is water,” launched a dramatic shift in people’s minds. No longer were people discussing the moods and personalities of human-like gods. Instead, these early philosophers looked for patterns in nature to explain natural events. Rather than relying on stories and myths, people were beginning to test truths on a first-hand basis.
One of the first documented thinkers who promoted this idea—that the phenomena of nature cannot be explained by supernatural gods or magic, but by observable facts—was Anaximander (610–547 BC). Starting with Thales’ idea that water is the origin of all things, and the observation of humidification and cloud formation, Anaximander concluded that in earlier times, the Earth must have been covered by water. The existence of fossils further strengthened his view, which led to the conclusion that humans also had to have emerged from water.
Not long after, Empedocles (490–430 BC) offered an explanation of why organisms in nature look as if someone had designed them for a specific purpose. Those organisms happened to have properties that allowed them to survive in their environment. Those that did not have such properties died and hence, were not part of nature anymore. He also held the view that life could have developed without an underlying purpose or a godly creator.
Further support of this idea was provided by Aristotle (384–322 BC). Like Charles Darwin 2,000 years later, he was an explorer of nature, analyzing and classifying more than 500 different animal species. He recognized that animals’ properties were specifically adapted to their environment. He disagreed with Empedocles, though, as to whether or not they had a higher purpose.
Later, in the Roman empire, Lucretius (97–55 BC) took interest in the subject and based his work De Rerum Natura (“On the Nature of Things,” published by Cicero [106–43 BC] after Lucretius’ death) on the writings of Epicurus. The book describes the universe as a purely mechanistic entity, without supernatural influence. This idea thrived within an environment of the then-popular Stoicism, the view that to attain happiness, you need to understand nature. Contrary to the theory of evolution, people still believed that everything happened for a reason, that the world was designed for a purpose (teleology).
With the deterioration of the Roman Empire came the attempt to keep the empire together by raising Christianity to the state religion. Augustin of Hippo (354–430)—one of the so-called “Church Fathers” with a strong influence on the philosophy and theology of Christianity—argued against the idea of literal interpretation of the Bible, claiming that new species can develop.
The Roman Empire fell in 476, and it took until the 9th century for learning centers in the Middle East to be rediscovered and to translate old Greek and Latin books. Similarly to Aristoteles, Al-Biruni (776–868) categorized in his Book of Animals over 350 different animal species, their environments, and their places on the food chain. One of his notable discoveries was that animals are constantly in a fight for survival, and that successful properties of the animals are inherited to the next generation, resulting in adaptations and even new species.
The zenith of Arabic scholarship was with Nasr al-Dn Ts, a Persian polymath (1201–1274). He stated that “The organisms that can gain the new features faster are more variable. As a result, they gain advantages over other creatures. […] The bodies are changing as a result of the internal and external interactions.” He even theorized that humans are but a middle step of an evolutionary stairway, with animals as the precursors, and humans with spiritual perfection as the successors.
As climatic conditions in Europe improved during the High Middle Ages, scientific progress returned. From the Middle East, translations from Arabic books, old Greek and Latin writings, and even scientists returned to Europe, creating the foundation for people like Thomas Aquinas (1225–1274). His view was that God provided an objective world with cause and event in an endless loop, and that animals had a god-created potential to develop into new species. Besides the initial potential of nature to create this diversity, there would be no further godly interventions in this progress.
The Crusades and the Mongol Invasion in the Middle East, and the subsequent destruction of libraries and the fabric of society, left Europe as the keeper of knowledge. It took until René Descartes (1596–1650) for a revival of a mechanical view of the universe. Partly to blame for this delay in scientific discovery were the Little Ice Age (1300–1750), a strengthening of the Catholic Church, the persecution of heresy by religious inquisition, and illiteracy in the general population.
Benot de Maillet (1656–1738) was a student of geology. Starting from a theory by Descartes, namely that the Earth had originally been entirely covered by water, and by studying fossilized shells embedded in sedimentary rocks on mountains high above sea level, he concluded that the Earth must have been created not by a singular act, but by a slow, natural process. He estimated the true age of the Earth at around 2 billion years and assumed that humans must have been developed from animals that came out of the water.
Finally, in the following two centuries, the idea of evolution took off.
- First, while fossils were found and considered the remains of life forms from ancient times, the fossil record was very sparse. This gap began to close thanks to industrialization, which increased the need for professional geologists, and coal mining uncovered new fossils.
- Second, the comparison of specimens from different geographical areas provided evidence for a relationship between the species: the greater the distance between two species, the more they differed from each other.
- Third, the ancient writings became known and available to more and more people. Book printing grew from a few hundred titles per year in the 17th century to thousands of titles per year in the 18th century.
- Fourth, the general science of categorizing the natural world created the foundation for further scientific theories including the theory of evolution by filling gaps, focusing the research on questions that remained open.
Theory of Evolution The theory of evolution states that the process of evolution tends to create systems in each new generation that are better adapted to the environment than the parent generation.
With this background in mind, Charles Darwin’s (1809–1882) Theory of Evolution in his book Origin of Species looks like a much smaller step than when taken on its own. It did not come out of the void and we have to remember those who paved the way. Charles Darwin’s research certainly was a heroic act, given the resistance he faced (and his work still faces). His integration of all the pieces that were available to him, including his own research that he conducted when taking part in the voyages of the HMS Beagle around the world, was revolutionary—despite having an evolutionary record.
Likewise, the history of the theory of evolution did not end with Darwin. There were (and still are) many gaps being filled. Advances in other fields of technology opened the door for genetic research and we are only now slowly beginning to understand the code in which life is written.
Science is a collaborative enterprise spanning the generations. We remember those who prepared the way, seeing for them also.Carl Sagan, Cosmos: Blues for a Red Planet [Carl Sagan, Cosmos: Blues for a red planet, 2002]