This blog post explores the relationship between evolution and progress through Darwin’s Confidence. Based on the debate between Dawkins and Gould, it takes an in-depth look at whether evolution truly signifies progress.
The book Darwin’s Confidence takes the form of a fictional debate between two world-renowned biologists, Dawkins and Gould. Before discussing the fifth story in this book, ‘Can We Call the Evolution of Organisms Progress?’, it seems necessary to first address the terms ‘evolution’ and ‘progress’.
Evolution refers to the gradual changes that living organisms undergo over tens of millions of years as they pass down through generations on Earth. Darwin’s theory of evolution has long been accepted among scientists. Evolutionary theory presents fossils found in geological strata as evidence, stating that organisms have changed through this process. I believe this is a point agreed upon not only by Gould and Dawkins but by many others.
Evolutionary theory has become a foundational theory in biology, enabling us to explain biological diversity and the complexity of ecosystems. The process by which species adapt and change through natural selection, driven by the combination of various environmental factors and genetic variation, is widely accepted among biologists. In this process, mechanisms such as natural selection, mutation, gene flow, and genetic drift act to determine the evolutionary paths of living organisms.
So, what exactly is the “progress” that Gould and Dawkins discuss in this book? Gould and Dawkins appear to have slightly different perspectives, but they seem to agree that an increase in biological complexity constitutes progress. Gould viewed the rise in complexity during evolution as one form of progress, while Dawkins added to this, seeing improvements in organisms’ adaptive capacity and functional efficiency as another aspect of progress.
Let us summarize Gould and Dawkins’ discussion on whether organisms have progressed. Dawkins argues that organisms have increased in complexity. He also presents the idea that organisms’ adaptability to their environment has gradually accumulated over generations. Based on these two reasons, Dawkins asserts that organisms have progressed over time. He particularly emphasizes the functional efficiency and ecological adaptability of organisms, viewing these traits as having been improved through evolution.
However, Gould counters that “while some organisms have increased in complexity, the vast majority of organisms—bacteria—have not.” He argues that one cannot claim overall biological complexity has increased. He stresses that biological evolution does not always lead to increased complexity, and that simpler organisms can also successfully survive and thrive.
He also addresses Dawkins’ second claim that organisms’ adaptability to their environment has progressively developed. Citing the extinction of all dinosaurs due to an asteroid impact, he argues that one cannot claim adaptation to the environment is progressive. Gould stresses that environmental changes and mass extinction events are not necessarily linked to progress, asserting that evolution is often governed by random and unpredictable events.
Dawkins then discusses eight evolutionary turning points. These turning points are irreversible, and because new evolution could emerge from them, organisms have progressed. Dawkins uses these turning points to criticize the Drunkard’s Model. Since organisms cannot retrace these evolutionary turning points, he argues that the wall in the Drunkard’s Model must be seen as shifting in the direction of increasing complexity. He emphasizes that specific branching points in the evolutionary process played a crucial role in determining the complexity and diversity of organisms.
The book concludes with Dawkins making this final argument, without presenting Gould’s rebuttal. Dawkins’ argument is clear and consistent, and his logical approach is persuasive to many readers. However, the lack of Gould’s rebuttal leaves readers feeling somewhat unsatisfied.
Personally, I agree with Dawkins’ assertion about evolutionary turning points and therefore believe organisms have evolved and progressed. The fact that complex organisms have steadily increased is self-evident. The emergence of eukaryotes and multicellular organisms from a time when only prokaryotes existed represents an enormous change. I believe the difference between organisms before evolution and those that became complex through evolution lies in their methods of adapting to the environment. Simply put, for organisms like bacteria, adapting to the environment is all they can do. They adapt within a given environment to increase their population and expand their range by moving, driven by external factors rather than their own power. However, multicellular organisms can actively seek out and move to environments more favorable for their survival. Comparing the passive adaptation of bacteria with the proactive environment-seeking ability of multicellular organisms, can we not argue that organisms have progressed?
There is one aspect of Gould’s argument I find difficult to grasp: the insistence that bacteria, as the most common species, must be chosen as the representative of life. There are multiple methods for establishing representative values in statistical data. The median, mean, and mode readily come to mind. Contrary to Gould’s argument, the other two representative values besides the mode could both serve as data supporting the notion that organisms have progressed. I couldn’t understand why he dismissed these two indicators as meaningless and claimed only the mode could represent organisms. Both Gould and Dawkins agreed that all life began with the simplest prokaryotes. On Gould’s graph, everything started at the leftmost wall, the simplest point. It is only natural that the most frequent value coincides with the starting point, since evolutionary speeds are not uniform. For example, if you drop a drop of ink into one corner of a water cup, before the ink spreads evenly throughout, the area where the ink was first dropped will naturally have the highest ink concentration compared to areas where no ink was dropped.
This does not imply that the frequency of appearance for the simplest organisms and the most complex organisms will eventually become equal. In the case of the water cup, the ink can spread only within the limited space available, so eventually, the ink will spread evenly throughout. However, the graph we are discussing for organisms has no such limit. Think of it as dropping ink into the ocean. Because there is no limit, the frequency of complex organisms appearing will be lower than that of the simplest organisms. Thus, it is only natural that the simplest organisms become the most frequent. However, it was difficult to understand the claim that only this most frequent value is meaningful.
According to Gould’s argument, the reason simple organisms can survive and thrive over long periods lies in their simplicity and efficiency. Simple organisms like bacteria possess superior adaptability compared to complex organisms and the ability to survive in diverse environments. They have very short generation times, enabling rapid evolution, and respond swiftly to environmental changes. From this perspective, Gould views simple organisms as playing a crucial role in the evolutionary process.
Furthermore, Gould argues that biological evolution does not always lead to increased complexity; sometimes, simplicity can be more advantageous for survival. For example, organisms like parasites maintain simple forms to efficiently utilize their host’s resources, which is a crucial element in their survival strategy. From this perspective, evolution is not merely a process of increasing complexity, but rather a process by which organisms find the optimal survival strategy within their given environment.
This book explores the complexity and multifaceted nature of evolutionary theory through the debate between Dawkins and Gould, providing readers with a deep understanding of evolution. Evolutionary theory is not merely a theory explaining how past life forms changed; it also plays a vital role in predicting how present and future life forms will change. Through this, we can better understand the diversity and complexity of life forms and become more aware of the importance of ecosystem conservation and biodiversity.
