Evolution: The Bad, the Good, and the Ugly by Mano Singham It is hard to believe that there could be any good news behind this mind-boggling statistic that implies that up to 47 percent of Americans are unwilling to accept a fundamental tenet of evolution and believe that human beings appeared by a special act of creation about 10,000 years ago. But there is a nugget of good news to be found, since this is the first time that even a simple majority of Americans had accepted that statement. But even that small glimmer of hope is buried under more bad news. Even though a majority has come around to the accepted scientific view of the origin of humans, the US still lags far behind other countries. In a New York Times article on February 1, 2005, Dr. Joe Miller, director of the Center for Biomedical Communications at Northwestern University is quoted as saying that in other industrialized countries, 80 percent or more typically accept evolution, while most of the others say they are not sure and very few people reject the idea outright. He goes on to say that in socially conservative, predominantly Catholic countries like Poland, perhaps 75 percent of people surveyed accept evolution, while in Japan it is close to a whopping 96 percent. So what is different about the US? There are some obvious reasons that can be postulated. One is that the US is in the grip of Biblical literalists who indoctrinate young children with young-Earth ideas and frighten them with the flames of hell if they should deviate from that dogma. Another is that evolution is either not being taught at all, or is being taught badly so as to be unconvincing, or its teaching is being deliberately undermined (such as using disclaimer stickers in biology textbooks that evolution is "only a theory," teaching of intelligent design as an alternative) by fraudulent claims that it is not a scientifically acceptable theory. The response to these kinds of explanations is to argue for more and better teaching of evolution in schools. While I am all in favor of better teaching of anything, I am not convinced that inadequate teaching of evolution is the main problem. It may lie in the way the nature of science is taught, and correcting this might require us to pay more close attention to the image we convey of how science itself works and evolves. This may require us to focus, not on more teaching of evolution or any other specific topic, but more generally on the history and philosophy of science. Science is Not a Smorgasbord This is because science is taught pretty much as a set of end results and disconnected facts: The universe is over ten billion years old. The Earth revolves around the Sun. Atoms are made from protons, neutrons, and electrons. Trees take in carbon dioxide and release oxygen. Our genetic information is encoded in our DNA. It is as if scientific facts are arranged on some kind of buffet table and anyone is free to pick and choose items depending on their personal preferences. Something sounds reasonable? Accept it. Something disagrees with your religious or other beliefs? Reject it. But you cannot really do this with science because scientific facts are not disconnected entities. They are linked to each other by their underlying theories and individual results cannot be rejected without consequences. If you reject the age of the universe for whatever reason, then you are also rejecting all the other results associated with the theory of gravity and other physics theories that go into arriving at that age. These theories are not used just for the purpose of addressing cosmological questions but also play an important role in everyday life (the way our cars and airplanes work, the way our building are made, etc.) So people who reject the age of the universe should be very apprehensive about getting into a plane or car or walking into a building because they have effectively said that they have no faith in the theories that were used to construct them. As the philosopher of science Pierre Duhem said back in 1906 in The Aim and Structure of Physical Theory: "To seek to separate each of the hypotheses of theoretical physics from the other assumptions on which this science rests is to pursue a chimera; for the realization and interpretation of no matter what experiment in physics imply adherence to a whole set of theoretical propositions." But what about those people who do not reject specific results but instead reject an entire theoretical structure? For example, those who say that they can accept all the major theories of science (and the old age of the universe) but reject evolutionary theory as a complete unit because it disagrees with their religious beliefs? In other words, they believe that all species came about as special acts of creation. Can that be done? Can a single theoretical scientific structure like evolution be rejected and replaced with another (perhaps Biblically-based) one? Or pushing further, can one reject the findings of an entire modern scientific discipline (like biology) while accepting others (like physics and chemistry)? Scientific Knowledge is an Interconnected
Web ID supporters take great pains to claim that theirs is a scientific theory that has nothing to do with religion or God, and hence belongs in the school science curriculum. (This particular question whether ID can be considered a part of science or of religion will be revisited in a later posting. This is becoming a longer series than I anticipated…) ID advocates say that there are five specific biochemical systems and processes (bacterial flagella and cilia, blood clotting, protein transport within a cell, the immune system, and metabolic pathways) whose existence and/or workings cannot be explained by evolutionary theory and that hence one has to postulate that such phenomena are evidence of design and of the existence of a designer. The substance of their arguments is: "You can claim all the other results for evolutionary theory. What would be the harm in allowing these five small systems to have an alternative explanation?" Leaving aside the many other arguments that can be raised against this position (including those from biologists that these five systems are hardly intractable problems for evolutionary theory), I want to focus on just one feature of the argument. Is it possible to accept that just these five processes were created by a 'designer,' while retaining a belief in all the other theories of science? No you cannot. If some undetectable agent had intervened to create the cilia (say), then in that single act at a microscopic level, you have violated fundamental laws of physics such as the law of conservation of energy, the law of conservation of momentum, and (possibly) the law of conservation of angular momentum. These laws are the bedrock of science and to abandon them is to abandon some of the most fundamental elements of modern science. So rejecting a seemingly small element of evolutionary theory triggers a catastrophe in a seemingly far-removed area of science, a kind of chaotic 'butterfly effect' for scientific theories. Scientific theories are so interconnected that some philosophers of science have taken this to the extreme (as philosophers are wont to do) and argued that we can only think of one big scientific theory that encompasses everything. It is this entire system (and not any single part of it) that should be compared with nature. Pierre Duhem in his The Aim and Structure of Physical Theory (1906) articulated this position when he declared that: "The only experimental check on a physical theory which is not illogical consists in comparing the entire system of the physical theory with the whole group of experimental laws, and in judging whether the latter is represented by the former in a satisfactory manner." (emphasis in original) Of course, in practical terms, we don't do that. Each scientific subfield proceeds along its own path. And we know that there have been revolutions in one area of science that have left other areas seemingly undisturbed. But this interconnectedness is a reality and explains why scientific theories are so resistant to change. Scientists realize that changing one portion requires, at the very least, making some accommodations in theories that are connected to it, and it is this process of adjustments that takes time and effort and prevents trivial events from triggering changes. This is why it usually requires a major crisis in an existing theory for scientists to even consider replacing it with a new one. The five cases raised by ID advocates do not come close to creating that kind of crisis. They are like flies in the path of a lumbering evolutionary theory elephant, minor irritants that can be ignored or swatted away easily.
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