266 | Christoph Adami on How Information Makes Sense of Biology
Feb 19, 2024
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Christoph Adami, a professor at Michigan State University and an expert in information theory, delves into how information is essential for understanding biology and evolution. He discusses the concept of 'survival of the fittest' and how information transmission shapes it. The conversation covers the significance of genomes, epigenetics, and cultural evolution in passing down information. Adami also elaborates on the relationship between information theory and biological complexity, including the nuances of genomic data and its implications for understanding life.
Information is crucial in biology for survival and evolution.
Information theory aids in understanding genetics and complexity.
Information plays a vital role in the origin and growth of biological systems.
Deep dives
The Darwin Demon and the Law of Increasing Information in Evolution
The Darwin Demon analogy is used to explain how evolution operates by selecting beneficial mutations and discarding deleterious ones. This natural demon acts as a measurement device, distinguishing between mutations that increase fitness and those that decrease fitness. By retaining beneficial mutations, organisms increase their information about the environment, leading to greater fitness and adaptation. This concept aligns with the law of increasing information in evolution, which predicts that over time, the amount of information stored in a population's genomes should steadily rise. Complexity in organisms is synonymous with the amount of information they possess, and understanding the role of information sheds light on the origin and growth of complexity in biological systems.
Maxwell's Demon and the Relationship between Measurements and Information
Maxwell's Demon is a thought experiment involving a demon that selectively allows different gas molecules to pass through a door based on their speed. This has the potential to decrease entropy and seemingly violate the second law of thermodynamics. However, Rudolf Landauer's proof demonstrates that no actual violation occurs. Similarly, in biology, measurements made by organisms act as a type of demon, selecting mutations (measurements) that increase fitness and discarding those that decrease fitness. This process extracts information about the environment, aiding in adaptation and increasing information in genomes. Measurements have the ability to reduce entropy and provide critical insights into the relationship between measurements, information, and biology.
Applying Information Theory to Genetics and Evolution
Information theory finds limited use in the field of biology, though there are notable researchers exploring its application. Information theory provides a valuable framework for understanding genetics, evolution, and complexity. The correlation between genomes and environmental predictions is a significant aspect of biological information. The genomes of organisms make predictions about their environment, leading to fitness and adaptation. Understanding the role of information in biology allows for a deeper exploration and explanation of the complexity observed in biological systems. By utilizing information theory, researchers can gain insights into the relationship between genomes, environment, and evolution.
The Nature of Information and Evolutionary Processes
Information is closely tied to evolutionary processes, acting as the basis for fitness and adaptation. In biology, information is contextual and defined as that which allows for accurate predictions about a particular system. Biological systems gather information through mutation and selection, retaining advantageous mutations while discarding deleterious ones. The concept of information in biology can help explain the growth and complexity of organisms over time. The Law of Increasing Information in Evolution posits that the amount of information in genomes should steadily rise as organisms adapt to their environment and increase their fitness. Understanding the connection between information and evolution provides valuable insights into the biological world.
The role of information in the origin of life
The podcast discusses the concept of the origin of life and how information plays a crucial role in it. The speaker introduces the idea of the RNA world, where RNA molecules can store information and also serve as machinery for replication. The replication process gradually transfers information from the hardware (the RNA molecule) to the software (the sequence), allowing for Darwinian evolution to take hold. The seeping of information into the sequence is facilitated by a mechanism of faster replication through complementary bases and the attachment of broken-off pieces. The origin of life is seen as a transition from a high-entropy state to a lower-entropy state, where information gradually accumulates.
The human capacity for manipulating information
The podcast explores the unique capabilities of human beings in manipulating and replicating information. Unlike other species, humans have the ability to write down and store information, allowing for knowledge to be passed on from generation to generation. This ability to make predictions and transmit knowledge through books and other media is considered a form of intelligence. It enables humans to make accurate predictions over longer timescales, such as understanding and responding to global warming. The combination of the human brain's storage of information during a lifetime and the permanence of written records is seen as a key factor in the success of the human species.
Evolution is sometimes described -- not precisely, but with some justification -- as being about the "survival of the fittest." But that idea doesn't work unless there is some way for one generation to pass down information about how best to survive. We now know that such information is passed down in a variety of ways: through our inherited genome, through epigenetic factors, and of course through cultural transmission. Chris Adami suggests that we update Dobzhansky's maxim "Nothing in biology makes sense except in the light of evolution" to "... except in the light of information." We talk about information theory as a subject in its own right, and how it helps us to understand organisms, evolution, and the origin of life.
Christoph Adami received his Ph.D. in physics from Stony Brook University. He is currently professor of Microbiology and Molecular Genetics as well as Physics and Astronomy at Michigan State University. Among his awards are the NASA Exceptional Achievement Medal and the Lifetime Achievement Award from the International Society for Artificial Life. His new book is The Evolution of Biological Information: How Evolution Creates Complexity, from Viruses to Brains.
