# Unit of Selection > **Machine-Evolution Nexus:** [[articles/Digital Darwinism and the Invisible World of Machine Evolution|Digital Darwinism and the Invisible World of Machine Evolution]] places this node within the history and governance of substrate-independent evolution. **Domain:** Evolution / Philosophy of Biology **Doc Type:** Canonical Wiki Node **Maturity:** Developed ## Definition A unit of selection is an entity at a level of organization whose heritable differences produce differential reproductive success. ## Nexus Context Genes, cells, organisms and groups can become relevant units under different causal conditions. Major transitions alter which units reproduce as integrated wholes. ## Evidence Boundary The unit cannot be chosen rhetorically; it must be inferred from heredity, fitness effects and conflict structure. A platform containing many agents is not automatically a superorganism. ## Relationships [[wiki/Major Evolutionary Transitions|Major Evolutionary Transitions]], [[wiki/Population|Population]], [[wiki/Differential Reproductive Success|Differential Reproductive Success]], [[wiki/Distributed Intelligence|Distributed Intelligence]] - **Edge source route:** [[collections/Edge|Edge]] connects this topic to exact Annual Question passages promoted into the Simple Reminders archive. ## Sources / Provenance - Lewontin (1970); multilevel-selection literature. ## Simple Reminders, Quotations, and Thoughts > “I think that Darwin's invention of the theory of evolution by natural selection outshines them all. It is perhaps the only truly general theory in Biology, a field much more complex than physics. If we discover life elsewhere in the universe it is likely to be the only biological theory that will carry over from our terrestrial biology. Darwin's theory reduced tremendously the complication of zoological data. Critically, as with the telescope, it has put tremendous pressure on the previous world-view to accommodate man as "merely" a part of a much larger nature. This pressure is still largely being resisted, but the outcome is clear.” > **— Christopher G. Langton**, *1999, Edge Annual Question, “What Is The Most Important Invention In The Past Two Thousand Years?”* [[reminders/Evolution/Darwin's Theory Outshines Every Other Biological Invention by Christopher G. Langton|Darwin's Theory Outshines Every Other Biological Invention by Christopher G. Langton]] > “I navigate through this storm of information using my favorite conceptual compass: Darwin's theory of evolution by natural selection. Application of evolutionary principles often draws attention to paradoxes and flaws in arguments. These problems, if recognized, are often swept under the rug, but they become unavoidably conspicuous when the correct alternative argument is formulated. One of my research strategies is to identify medical conventional wisdom that is inconsistent with evolutionary principles. I then formulate alternative explanations that are consistent and then evaluate all of them with evidence.” > **— Paul W. Ewald**, *2010, Edge Annual Question, “How Is The Internet Changing The Way You Think?”* [[reminders/Evolution/Darwinian Thinking Is a Compass Through Complexity by Paul W. Ewald|Darwinian Thinking Is a Compass Through Complexity by Paul W. Ewald]] > “I believe that all life, all intelligence, all creativity and all 'design' anywhere in the universe, is the direct or indirect product of Darwinian natural selection. It follows that design comes late in the universe, after a period of Darwinian evolution. Design cannot precede evolution and therefore cannot underlie the universe.” > **— Richard Dawkins**, *2005, Edge Annual Question, “What Do You Believe Is True Even Though You Cannot Prove It?”* [[reminders/Evolution/Design Cannot Precede Evolution by Richard Dawkins|Design Cannot Precede Evolution by Richard Dawkins]] > “We humans can, and do, make up our own purposes, but ultimately the universe has none. All the wonderfully complex, and beautifully designed things we see around us were built by the same purposeless process — evolution by natural selection. This includes everything from microbes and elephants to skyscrapers and computers, and even our own inner selves.” > **— Susan Blackmore**, *2006, Edge Annual Question, “What Is Your Dangerous Idea?”* [[reminders/Evolution/Evolution Builds Complex Design Without Purpose by Susan Blackmore|Evolution Builds Complex Design Without Purpose by Susan Blackmore]] > “The hardest choice I had to make in my early scientific life was whether to give up the beautiful puzzles of quantum mechanics, nonlocality, and cosmology for something equally arresting: To work instead on reverse engineering the code that natural selection had built into the programs that made up our species' circuit architecture. In 1970, the surrounding cultural frenzy and geopolitics made first steps toward a nonideological and computational understanding of our evolved design, "human nature", seem urgent; the recent rise of computer science and cybernetics made it seem possible; the almost complete avoidance of and hostility to evolutionary biology by behavioral and social scientists had nearly neutered those fields, and so made it seem necessary.” > **— John Tooby**, *2012, Edge Annual Question, “What Is Your Favorite Deep, Elegant, Or Beautiful Explanation?”* [[reminders/Cybernetics/Falling into Place Entropy, Galileo's Frames of Reference, and the Desperate Ingenuity of Life by John Tooby|Falling into Place Entropy, Galileo's Frames of Reference, and the Desperate Ingenuity of Life by John Tooby]] > “There are several causes for concern. To begin with, it is a correct assumption that natural selection is largely agnostic with regard to intelligence. We large-brained hominids like to think that all the information-crunching power in our hypertrophied cortexes will eventually allow us to solve the big problems of modern times, allowing our descendants to persist into the distant future. But it ain't necessarily so. Dinosaurs were a lot smarter than cockroaches, and Australopithecines were Einsteinian by comparison, yet the roaches have had a much longer run, and are widely expected to outlast Homo sapiens.” > **— Douglas T. Kenrick**, *2013, Edge Annual Question, “What *should* We Be Worried About?”* [[reminders/Evolution/Is Idiocracy Looming by Douglas T. Kenrick|Is Idiocracy Looming by Douglas T. Kenrick]] > “The idea sounds fatuous in the extreme…until you remember that objects as big and complex as whales, dinosaurs, and sumo wrestlers got built in a moderately analogous fashion: they began as minute, nanoscale structures that duplicated themselves, and whose successors then differentiated off into specialized organs and other components. Those growing ranks of biological marvels did all this repeatedly until, eventually, they had automatically assembled themselves into complex and functional macroscale entities. And the initial seed structures, the gametes, were not even designed, built, or programmed by scientists: they were just out there in the world, products of natural selection. But if nature can do that all by itself, then why can't machines be intelligently engineered to accomplish relevantly similar feats?” > **— Ed Regis**, *2009, Edge Annual Question, “What Will Change Everything?”* [[reminders/Evolution/Molecular Manufacturing Copies Evolution's Bottom-up Construction by Ed Regis|Molecular Manufacturing Copies Evolution's Bottom-up Construction by Ed Regis]] > “We know that gut-feelings, such as reactions of empathy or disgust, have a major influence on how children and adults reason about morality. And no serious theory of moral development can ignore the role of natural selection in shaping our moral intuitions. But what I like about Macnamara's proposal is that it allows for moral realism. It allows for the existence of moral truths that people come to discover, just as we come to discover truths of mathematics. We can reject the nihilistic position (help by many researchers) that our moral intuitions are nothing more than accidents of biology or culture.” > **— Paul Bloom**, *2005, Edge Annual Question, “What Do You Believe Is True Even Though You Cannot Prove It?”* [[reminders/Evolution/Moral Development Cannot Ignore Natural Selection by Paul Bloom|Moral Development Cannot Ignore Natural Selection by Paul Bloom]] > “Morality is made of meat. It is a collection of biological and cultural solutions to the problems of cooperation recurrent in human social life. Which problems? Caring for families, working in teams, trading favors, resolving conflicts. Which solutions? Love, loyalty, reciprocity, respect. The solutions arose first as instincts, designed by natural selection; later, they were augmented and extended by human ingenuity, and transmitted as culture. These mechanisms motivate social, cooperative, and altruistic behavior; and they provide the criteria by which we evaluate the behavior of others. And why is morality felt to be so important? Because, for a social species like us, the benefits of cooperation (and the opportunity costs of its absence) can hardly be overstated.” > **— Oliver Scott Curry**, *2016, Edge Annual Question, “What Do You Consider The Most Interesting Recent [Scientific] News? What Makes It Important?”* [[reminders/Evolution/Morality Is Made of Meat by Oliver Scott Curry|Morality Is Made of Meat by Oliver Scott Curry]] > “Natural selection shapes systems whose complexity is indescribable in terms satisfying to human minds. Some may feel this is nihilistic. It does discourage hopes for finding simple specific descriptions for all biological systems. However, recognizing a quest as hopeless is often the key to progress. As Haldane put it, "We are thus brought face-to-face with the conclusion which to the biologist is just as significant and fundamental, just as true to the facts observed, as the conclusion of mass persists is to the physicists… the structure of a living organism has no real resemblance in its behavior to that of a machine… In the living organisms…the "structure" is only the appearance given by what seems at first to be a constant flow of specific material, beginning and ending in the environment."” > **— Randolph Nesse**, *2012, Edge Annual Question, “What Is Your Favorite Deep, Elegant, Or Beautiful Explanation?”* [[reminders/Evolution/Natural Selection Builds Unimaginably Complex Systems by Randolph Nesse|Natural Selection Builds Unimaginably Complex Systems by Randolph Nesse]] > “My Edge answer this year has to be evolution by natural selection. Not only does it explain how we all got here and how we are and behave as we do, it can even explain (at least to my fairly critical satisfaction) why many people refuse to accept it and why even more people believe in an all-powerful Deity. But since other Edge respondents are likely to have natural selection as their favorite deep, elegant, and beautiful explanation (it has all three attributes, in addition to wide ranging explanatory power), I'll have to hone in on one particular instance: the explanation of how humans acquired language—by which I mean grammatical structure.” > **— Keith Devlin**, *2012, Edge Annual Question, “What Is Your Favorite Deep, Elegant, Or Beautiful Explanation?”* [[reminders/Evolution/Natural Selection Explains How We Got Here by Keith Devlin|Natural Selection Explains How We Got Here by Keith Devlin]] > “Human being have evolved to behave rationally in a given context ‹ to follow the logic of the context. Following the survival logic of the given context is how natural selection works. We cannot change the logic in a context any more than we can change the mathematical fact that 1 + 1 = 2. In the case of terrorism, what we can change is the context. Doing so will inevitably require enormous wisdom, knowledge, and resources. Maybe this is where the true future greatness lies for the most powerful nation on Earth.” > **— Keith Devlin**, *2001, Edge Annual Question, “What Now?”* [[reminders/Evolution/Natural Selection Rewards Survival in Context by Keith Devlin|Natural Selection Rewards Survival in Context by Keith Devlin]] > “When most people think about evolution by selection, they conjure up phrases such as "survival of the fittest" or "nature red in tooth and claw." These focus attention on the Darwinian struggle for survival. Many scientists, but few others, know that evolution by selection occurs through the process of differential reproductive success by virtue of heritable differences in design, not by differential survival success. And differential reproductive success often boils down to differential mating success, the focus of Darwin's 1871 theory of sexual selection.” > **— David M. Buss**, *2011, Edge Annual Question, “What Scientific Concept Would Improve Everybody's Cognitive Toolkit?”* [[reminders/Evolution/Sexual Selection Rewards Mating Success by David M. Buss|Sexual Selection Rewards Mating Success by David M. Buss]] > “Science helps shape how we see ourselves. Words also matter to perception, and perception matters to behavior. Consider what the theory of natural selection did to our view of humans in the biological world. We should be worried about the new era of Anthropocene—not only as a geological phenomenon, but also as a cultural frame.” > **— Jennifer Jacquet**, *2013, Edge Annual Question, “What *should* We Be Worried About?”* [[reminders/Evolution/The Anthropocebo Effect by Jennifer Jacquet|The Anthropocebo Effect by Jennifer Jacquet]] > “We begin with the individual organism as the primary unit of biology and society because the organism is the principal target of natural selection and social evolution. Thus, the survival and flourishing of the individual organism—people in this context—is the basis of establishing values and morals, and so determining the conditions by which humans best flourish ought to be the goal of a science of morality. The constitutions of human societies ought to be built on the constitution of human nature, and science is the best tool we have for understanding our nature.” > **— Michael Shermer**, *2013, Edge Annual Question, “What *should* We Be Worried About?”* [[reminders/Evolution/The Is-ought Fallacy of Science and Morality by Michael Shermer|The Is-ought Fallacy of Science and Morality by Michael Shermer]] > “One of life's most profound questions has been thought to be unanswerable. That question is, "Why is life so full of suffering?" Impatience with centuries of theological and philosophical speculation has led many to give up on the big question, and to ask instead only how brain mechanisms work, and why people differ in their experiences of suffering. But the larger question has an answer, an evolutionary answer. The capacities for suffering — pain, hunger, cough, anxiety, sadness, boredom and all the res — have been shaped by natural selection. They seem to be problems because they are so painful and because they are aroused only in adverse circumstances, but they are, in fact, solutions.” > **— Randolph Nesse**, *2001, Edge Annual Question, “What Questions Have Disappeared?”* [[reminders/Evolution/Why Is Life So Full of Suffering by Randolph Nesse|Why Is Life So Full of Suffering by Randolph Nesse]]