Creationists are fond of asking "What's the use of evolution?" in the mistaken hope that it doesn't have one.
Obviously such a question is no test of the truth of a scientific proposition. Take the astronomy of our solar system as an example: no-one has yet made a single cent out of the proposition that Saturn has rings, or that Mars has two moons, or that Jupiter is the largest planet: yet not even creationists deny that these propositions are true.
For most fans of evolutionary biology, the main benefit of evolution is that it makes sense out of what would by any other hypothesis (including fiat creationism) be a meaningless jumble of facts. To quote Dobzhansy's famous words: "
Nothing in biology makes sense except in the light of evolution".
Such a statement, while true, will, however, cut no ice with creationists, who
want biology to make no sense so that they can ascribe it to God Moving In Mysterious Ways, and who therefore hate and fear any scientific explanation of the things that they want to find mysterious. When they ask for a
use for evolutionary biology, they mean one that can be measured in dollars and cents.
Fortunately, evolutionary biology has many such applications. What follows is a sample of the practical benefits derived from an evolutionary perspective.
===
The Ames Test
This is a standard method of biological assay for measuring the mutagenicity of a substance: it relies crucially on measuring the number of
beneficial mutations caused by the substance being tested, as revealed by the evolution of bacteria that can manufacture their own histidine.
Clearly, anyone who's been duped by the creationist dogma of "no beneficial mutations" could never have thought of this technique and would not believe that it would work.
Phylogenomics
In a recent thread
Tag mentioned phylogenomics. Figuring out the protein function of a gene by comparing it with known functions of similar genes can be done naively by guessing that similar looking genes have similar protein functions; but we can improve on this by applying our knowledge of the evolutionary relationships of the organisms in question.
Obviously, a creationist couldn't apply this method, because a creationist would believe that the phylogenies employed are false: and adding in false data would not improve anything.
Evolutionary algorithms
Suppose that you want to produce a device to perform a certain task. Suppose further that you have a computer program that can calculate how good a given design would be at performing this task, but that your ability to perform this calculation does not allow you to figure out what the best design is. This sort of optimization problem a very common situation.
Then the way to proceed is obvious from an evolutionary point of view. Get your computer to start with any design you like. Make copies of it (simulating reproduction) that vary randomly from their parent (simulating mutation). Select which of these copies "survive" based on how good they are at performing the task in question (simulating natural selection). Use the survivors as the next generation, and repeat the process of reproduction with mutation and selection over and over again, through many "generations".
As this process simulates evolution, it produces designs that are better and better suited to the task for which they are selected. This has been applied successfully to a wide range of problems in science, engineering, computer science, logistics, and mathematics.
A creationist, dogmatically rejecting the ability of evolution to produce good solutions to complex problems, would not think of employing this method; and anyone who tried to simulate what creationists
think the theory of evolution is ("pure random chance" and suchlike idiotic catchphrases) would achieve results no better than chance would dictate.
Automated evolution of functional molecules
A similar method can be employed to produce a molecule with a desired function. However, as it is computationally very difficult to find out what a given protein molecule will do, it is necessary to make the molecules. This task, too, can be automated. The following account is from
an article on Berkeley University's evolution archive:
The term "directed evolution" is a bit misleading since it might suggest that the scientist directs individual steps in the process ("Tweak this...change that...now rotate this end of the molecule a bit..."). Actually, the only thing that Andy "directs" is selecting the job that the final RNA product ought to perform. The rest of the evolutionary process can be automated in fact, Andy's lab has programmed robots to do the tedious, repetitive work.
This process of engineering via evolution is quite different from engineering via design. When Andy sets out to engineer a molecule by evolution, he decides if the molecule ought to bind a particular type of cell, bind a particular protein, or cause a particular chemical reaction. The evolutionary process then tries out more than a million billion (that's 1,000,000,000,000,000!) different molecules and builds the one that does the job the best. Andy doesn't know what the "winning" molecule will look like or exactly how it will get the job done he just knows that it will work.
Machines synthesize billions of DNA sequences, and use them to build the corresponding RNA molecules. The robots then put the RNA to the test to see which molecules can perform the desired task. The RNA sequences that perform best are kept, and most of the rest are weeded out. The selected RNAs are used to build corresponding DNA, which is then copied. These steps are automatically repeated until an almost pure pool of useful RNA is built. Andy's job here is just to tell the machines what procedure to follow and set the works in motion.
Again, this depends crucially on the central idea of evolution: that random variation plus selection will produce good "design" without intelligent intervention: exactly the proposition that creationists have spent the last century-and-a-half denying.
The discovery of tetherins.
The discovery of tetherins is an interesting story, which you can read
here. Based on the observation that HIV evolved from SIV, on the observation that the Vpu gene in particular had evolved since transmission of the disease from apes to humans, and on the principle that evolution is not a matter of "random chance" but adaptive, scientists naturally asked
why Vpu had evolved, and what it was adapting to. Research into this question led directly to the discovery of tetherins, proteins that form part of the innate immune system.
Creation of live vaccines
If we cultivate a virus that normally affects humans in alternative host cells, the virus will evolve to adapt to the new conditions. This adaptation will, of course, make it less fit to attack a human host. For example, the oral polio vaccine is produced by cultivating the polio virus in monkey kidney cells; once they have evolved to thrive in these conditions, they are no good at attacking human nerve cells. They can then be used as a vaccine, since, administered to a human host, they will trigger the immune system but will not produce the crippling neurological damage usually associated with polio.
Besides polio, similar approaches have been used to produce live vaccines against the measles, mumps, rubella, chicken pox and yellow fever viruses, and against the bacteria that cause typhoid.
Evolutionary biology also tells us how these vaccines should be deployed. Once an attenuated virus has been administered to a patient, it can start evolving back to a form effective in humans. This will not harm the patient, because by the time the virus has evolved back to a form effective in humans, the patient will have acquired immunity. However, there is the possibility of transmitting the evolved form to an unvaccinated person. Therefore, live vaccines should be used in simultaneous mass vaccination programs, where a whole city full of people is vaccinated over a single weekend.
Molecular phylogeny and epidemiology
The methods of molecular phylogeny allow epidemiologists to track and understand the spread and origin of infectious diseases, by allowing them to construct family trees of pathogens. Exactly the same techniques, of course, are used to construct evolutionary trees of higher taxa and to confirm the predictions of evolutionary theory: to demonstrate, for example, that the closest relatives of living archosaurs are birds, and that coelacanths are closer to humans then they are to herrings.
Identifying regulatory gene sequences
It is easy enough to find a protein-coding gene by looking for the promoter and terminator sequences that identify where it starts and finishes. It is harder to find non-coding sequences of DNA that have a useful regulatory function. The theory of evolution provides us with a solution: when species diverge, natural selection should conserve functional non-coding DNA but not non-functional DNA, which will be subject to genetic drift without selection: this difference will show up more strongly the greater the divergence between species. Hence, we can identify these functional sequences by comparison between the genomes of distantly related species such as
humans and puffer fish.
All this, of course, is sheer nonsense to creationists, so if they ever bothered to take their noses out of their little pamphlets and look at some actual science, they would doubtless be irritated to learn how well it works.
Anitbiotic usage
Understanding evolutionary biology is key to the responsible use of antibiotics; ignoring it can be disastrous. Dr Randolph Nesse, physician and evolutionary biologist, has
this chilling tale to tell:
In his talk, Nesse related a tale of a hospital whose medical staff clearly needed to better understand evolutionary medicine. Several hospitals were rotating antibiotics, so they’d use one for six months, then they’d all agree to use another for the next six months, and another one for the next six months. This is the ideal way to create antibiotic resistance as fast as you can.
Creationists combine their purported acceptance of "microevolution" with their denial of beneficial mutations by asserting (wrongly) that all antibiotic resistance is inherited, so that it can only be amplified in the gene pool by natural selection, but cannot evolve
de novo. This is, of course, rubbish, as has been demonstrated time and again in the lab by very simple and unequivocal experiments. Any attempt to model the evolution of antibiotic resistance on the premise of this absurd creationist dogma would be doomed to failure and have catastrophic results for patients. Fortunately, there is no chance of creationist dogma ever having any effect on healthcare.
Biostratigraphy
Geology and evolution are inextricably intertwined: not only does geology help us to understand evolution, but, conversely, evolution helps us to understand geology, as, for example, in the use of biostratigraphic methods.
Of course, these self-same geological methods are universally used commercially to help locate oil, coal, natural gas, and other valuable mineral deposits, and as such are of enormous practical value.
If young-Earthism and "flood geology" had merit, and real geology had none, then obviously God's Own Truth of flood geology would be a better basis for searching for oil then the Wicked Lies Of Evil-utionists. Yet we note that there is no such thing as a creationist oil company. If creationists had the courage of their convictions, they might stop spending their money on "Creation Museums" and instead invest a little of it on a practical demonstration of their superior wisdom. But apparently, dumb though creationists may be, they're not quite dumb enough to risk any of their money on the proposition that their beliefs might be correct.
===
So my question is, does anyone any have stuff to add? I know I've seen more examples, but without remembering the specific details it's hard to track them down.
Edited by Dr Adequate, : No reason given.
™ Version 4.2