Maybe the OP could expand on this counterfactual scenario. For example, in this alternate timeline, when biologists are asked to describe the history of life, how do they answer? Do they know the age of the Earth? Would they still be talking about special creation, with each species appearing, without ancestors, in its present form? Would they believe in some kind of Lamarckian evolution?
Would they say, “We know the Earth is billions of years old. We can see from the fossil record that forms have changed over time, and as we go back in time, they seem to converge to a common ancestor. But for the life of us, we just can’t think what could be driving this constant, and yet strangely adaptive, change.” ?
I think any teaching or other discussion of breeding and how to do it actually IS an articulation of part of the theory of evolution, although obviously a part that Darwin was not the first to articulate.
A recent issue of Scientific American was devoted to Darwin’s articulation of the theory.
I think it depends on what the OP is means by the theory never being articulated. If you just took away the writing of Darwin, and assume that no one every postulates the whole shebang as a single theory, but all the useful parts of the theory are still being used, there would be almost no change. What the OP needs to articulate is what he thinks there is in place of Darwin’s theory. Lamarck’s theory of adaption? Life at steady state? Special creation?
Modern biomedical research would be crippled without the theory of evolution.
The evolutionary linkages between animal models and humans are absolutely critical to modern medical research. Without Darwin, we would have no reason to believe that a compound first identified for anti-angiogenic activity in zebrafish would have a similar effect on mice, much less in humans.
In addition, you’d have to kiss all medically relevant genetics goodbye. Risk factors for diseases ranging from cancer to alcoholism are identified using model organisms as basal as fruit flies and nematode worms. Once we’ve identified genes whose function is associated with those diseases in these basic models, we use sequence and structural homology to identify their counterparts in mammals. Without a solid understanding of how natural selection affects DNA sequence, this would be virtually impossible.
For example, one of the best-understood outcomes of natural selection at the genetic level is that genes with critical functions are more highly conserved (that is, have fewer protein sequence-level mutations) than genes with redundant or non-critical functions. Therefore, a fruit fly gene whose loss of function leads to uncontrolled cell proliferation and subsequently cancer may be expected to be highly conserved. We can take the sequence of this gene and use it as a search input to identify homologous genes in the human genome. This method is absolutely fundamental to modern biomedical research - I would not be surprised if every single major discovery made in the past 10 years involved it in one way or another.
Furthermore, within a single gene, regions of the protein product that are crucial for its function, such as binding sites or membrane-spanning domains, are more highly conserved than regions that aren’t directly involved in its function, such as hydrophilic unstructured loops on the protein surface that don’t bind anything. We can therefore align our novel cancer-associated fly gene with the homologous genes from a variety of animal lineages to identify which regions are conserved (and, presumably, important for gene function).
This allows us to look at sequence data from patients and unaffected individuals and see if any genetic variants associated with the patients feature disabling mutations in this gene. In addition, we can take a biochemical approach and figure out exactly what each conserved region of the gene is doing in the protein product. If, for example, the pro-cancer mutation is actually increasing protein activity, we can try to identify chemicals that bind to one of the conserved regions which could potentially inhibit the protein’s activity, abrogating the mutation’s effect.
This is just the tip of the iceberg. Areas of medically relevant research such as pathogen drug resistance, embryological development, neurobiology, stem cell biology, etc. are all dependent on the insights provided by evolutionary theory. Without Darwin, medicine would look the same today as it did decades ago.
I don’t see it. If I see that a gene does something in a fruitfly and see that humans have that gene (or a version of it), I don’t need evolution to experiment.
Evolution could’ve become like dark matter or dark energy, “something” we can’t quite put our fingers on it. We could see the effects but not the internal workings.
For example, pig organs are used no because they are the closest to us genetically (which would score points on the Darwin card), but because of size, great avalability and the fact that we’ve been around pigs for a long time a whatecer sickness we can share we’ve already shared.
Linnaeus was able to group living creatures into “similarity” groups without the benefit of evolution.
Without evolution, what would we discuss on the SDMB? Augmented chords in Anatolian music?
I’m also trying to understand why understanding natural selection was so crucial here. Is the idea that it’s expensive to check every single gene in a fruit fly to see if it appears in your cancer patients, but if the gene is “crucial”, you figure that your odds of finding it in the humans are good enough to justify looking for it?
While we can never make light the accomplishments of men like Newton, Darwin, et cetera it has very often been the case in the history of science that other men had similar ideas at similar times.
I have a hard time not believing that Darwin’s discoveries were more or less “inevitable.”
Evolution is necessary to explain why both species would carry the same gene, accomplishing the same function. Perhaps more importantly, evolution is required to understand how and why differences between the two homologs exist. Without evolutionary theory, we would not be able to make any inferences about the importance of one domain of a protein versus another. Any variation in conservation would be inexplicable.
That pigs are readily available does not negate the importance of their relative evolutionary closeness to us. If we had instead domesticated monitor lizards 10,000 years ago, pigs would still be a “better” model organism for the study of human organ transplantation.
How model organisms are selected for experiments is a complex issue. Every currently-available model system has its strengths and weaknesses, of which evolutionary similarity to humans is merely one (albeit important) attribute. As you noted, we often use pigs rather than primates for organ transplantation studies. This is because primates are expensive to maintain, grow extremely slowly, have poor fecundity, and working on them requires more stringent ethical standards. However, for some work that doesn’t require killing the animal, or from which significant results can be attained from a small sample size, primates are considered a “gold standard” because of their close evolutionary relation to humans.
To use another example, zebrafish are an increasingly popular model organism because you can do some pretty spectacular genetics with them, and being vertebrates, they are still close enough evolutionarily for discoveries to be useful. This is particularly true in fields such as developmental biology, in which many basic genetic mechanisms were already in place prior to the division between fish and higher vertebrate lineages.
Of course, if we had no idea that evolution occurred, we wouldn’t be able to apply any of the reasoning I described above. There would be no reason to even consider working on zebrafish, because fish and humans are separate kinds and any similarities must be coincidental. It would be laughable to propose that a discovery in fish might be applicable to human medicine.
Medicine is more than gross morphology, which is all Linnaeus had to go on. Modern genetics, particularly in biomedical research, is based on an assumption of descent with modification at the genetic level. As I noted in my previous post, homology searches and alignments would not make any sense without the assumption of shared ancestry followed by evolutionary divergence.
Yes, more or less. Except replace “expensive” with “prohibitively difficult given modern technology.” It can take years to tease out the interactions and biochemistry underlying just one gene’s function, much less the thousands that populate just a single organism. The ability to scan multiple genomes for homologous genes and then infer critical motifs and domains based on conservation is tremendously powerful.
I should also note that the importance of evolutionary distance depends on the nature of the research project. We use primates to study higher brain functions because these structures only evolved in the primate lineage. Conversely, nobody bothers to study cytoskeletal dynamics using monkeys, because the proteins involved (tubulin, actin, etc) are conserved all the way back to yeast.
Again, without an understanding of the evolutionary mechanisms that gave rise to these organisms, this sort of reasoning would be impossible. The fact that yeast and humans both have tubulin genes does not necessarily make it useful to study tubulin in yeast rather than humans. Evolutionary theory bridges that gap, by allowing us to make the educated guess that tubulin arose prior to the split between fungi and higher eukaryotes, and therefore the mechanisms through which tubulin works are likely to be conserved as well. Therefore, any discoveries we make regarding microtubule dynamics in yeast are likely to be applicable to microtubule dynamics in humans.
But even if you are a fully-fledged young-earth-creationist you can still see that those genes do the same and think* “well, the creator instilled similarities in all his creatures” *and from that thought go on and search for more of those. You can also see that the creator made creatures that are strikingly similar, biologically speaking, to humans.
The problem of assuming a creator for those genes is that there is a lot of junk present in those genes and their functions are sometimes not well defined or jury-rigged.
Thanks to modern genetics and evolution this is one of the worst examples for creationists to use when looking for an intelligent designer; however, it is a good place to see how life is really nature’s big ongoing hack.
What about Social Darwinism? I remember from AP US History that somewhere around the Gilded Age that because a popular idea inspired by the theory of evolution and shaped the politics and especially business of the time (I also believe it got us the wonderful buzz-phrase “survival of the fittest”). Without the theory catching on the current political and business landscape may have progressed differently without something like that to cling to and justify certain things.
This is highly overrated, and speculative. A staple of pop psychology, but very little real science exists on the subject.
I agree with Q.E.D. As much as I think Darwin’s theory is brilliant and wonderful, you don’t really need it to do biology. We wouldn’t have any interesting literature or science shows on evolution, but it’s impact on our daily lives would be unnoticeable.
However… it’s inconceivable that a culture as technologically advanced as we are would not have developed the theory, so it’s one of those questions that really doesn’t make sense.
And John Mace, saying that we “don’t really need it to do biology” may have been the case in the past, but that is less likely nowadays.
As for the OP, I agree with the position of the recent Scientific American editorial on Evolution: “Evolution should be taught as a practical tool for understanding drug resistance and the price of fish”.
I so wish I bought it but I recently saw a pamphlet in an antique store, circa late 40s I think that explained to a farmer a variety of breeding algorithms to breed out all variability once you have one or two excellent laying hens. Some were quicker then the other, but statistically you would still get some eggs that were less then ideal. At least you would know how many to expect so you could market properly.
I am guessing this never happened without Darwin. It was too many steps for the average farmer to figure out himself.
And unless killing all human beings that aren’t redheads = evolution, neither is it evolution when only drug-resistant micro-organisms or pests survive the use of said drugs.
Do you have a cite for the drug-resistant phenomenon not being evolution? I gave up when on a search only old creationist cites appeared with the peculiar conclusion that drug-resistance is not evolution.
On a serious note, modern medicine has been using evolution to gain ground on diseases:
Evolution of Drug Resistance in Mycobacterium tuberculosis: Clinical and Molecular Perspective
My WAG is that he mens that the resistance genes were already present in the bacteria population. So, it’s not the the bacteria evolved in order to became resistant, some already were.
AFAIK the problem here is** to assume that this is not evolution**, in some occasions resistance genes are there, but they are off or underutilized and the most important thing to notice: there is no guarantee that a specific gene will give an insect a “get out of [del]jail[/del] the elimination” card.
When, for example, mosquitoes evolve resistance to insecticides it is because the mosquitoes that survived had genes that allowed them to survive and pass the same resistance to their descendants; however,** this is also evolution**: