Usefulness of the theory of evolution

[MonDie]

I don't know a lot about biology yet. I know the theory of evolution applies when one is anticipating antibiotic or pesticide resistance, but what about the larger animals that reproduce less? Archaeology, ecology, physiology, and genetics contribute to our understanding of their evolutionary history, then our understanding of their evolutionary history contributes to what? Arguments against fundamentalism?

 

EDIT: I forgot that we apply artificial selection to our domesticated plants and animals, but that itself still doesn't do much to show how understanding something's evolutionary history might be useful.

Edited July 3, 2012 by Mondays Assignment: Die

[randomc]

there were some muslim med students in the uk not so long ago who won an internal dispute with their univerisity over non-attendance of evolution classes.

[Ringer]

Well, it helps our understanding of how nature works (which, IMO, is the basis of scientific research). To only think of science as a way to get something instead of learn things it can distort the purpose of scientific investigation. Finding evolutionary history can tell us what kinds of things can happen under different selective pressures as well as what different areas of the world were like in the past. Asking what good is it for is like asking why we would want to look into ancient kingdoms.

 

Evolution's utility can be discussed in many ways. As a doctor it can help one understand why common maladies are so common. This understanding helps one learn what might help these maladies. It can also help in that we now know we can infer reactions to medicines, genetic engineering, etc. using other animals that have those types of genes or need of those medicines. Without the underlying knowledge of what we have in common with other animals through evolution those things may not be used at all correctly.

 

 

 

[randomc]

How much physics does a mechanic need to fix a car? EVolution and medicine can't be so different.

[MonDie]

Finding evolutionary history can tell us what kinds of things can happen under different selective pressures as well as what different areas of the world were like in the past.

Maybe that could be applicable to the search for life on other planets, although I'm not familiar with astrobiology. However, even though that might be one clear application of an understanding of evolutionary history, astrobiology only concerns microorganisms. At least that's the case for now, although much of what is beyond this planet is still to be explored.

 

It can also help in that we now know we can infer reactions to medicines, genetic engineering, etc. using other animals that have those types of genes or need of those medicines. Without the underlying knowledge of what we have in common with other animals through evolution those things may not be used at all correctly.

Wouldn't that be applied genetics? Evolution isn't about anything physically part of us.

Edited July 4, 2012 by Mondays Assignment: Die

[Ringer]

Maybe that could be applicable to the search for life on other planets, although I'm not familiar with astrobiology. However, even though that might be one clear application of an understanding of evolutionary history, astrobiology only concerns microorganisms. At least that's the case for now, although much of what is beyond this planet is still to be explored.

 

It could be applied to many different scenarios. If we want to understand changes ecosystems have gone through and how they tend to develop, if ecosystems develop similarly under similar conditions and to what extent, how viruses and parasites can travel and survive, rate at which currently declining populations can be reformed after going through bottlenecks, which species are closely enough related to allow for inbreeding with severely depopulated species, etc.

 

Wouldn't that be applied genetics? Evolution isn't about anything physically part of us.

 

It's using the underlying fact of evolutionary similarities to infer results. If not for evolution we would not be able to comfortably assume that the genetic make-up of a mouse is similar enough to a humans to be able to do those sort of tests. Evolution is largely about what is a part of us, but it goes further than physiology, or something similar, and doesn't just say this is what this part of the body is it also shows why it is there and possible reasons things are going wrong with it. To dissociate just about anything in biology from evolution is doing a discredit to the vast understanding evolution has given the field.

 

More examples are the prevalence of sickle cell anemia in areas with a lot of instances of malaria, lactose intolerance, polydactyly in areas, etc.

[Arete]

"Nothing in Biology Makes Sense Except in the Light of Evolution" - Theodosius Dobzhansky.

 

The theory of evolution is so fundamentally entwined with almost all other aspects of biological science such that most of our current understanding of cellular biology, molecular biology, genetics and ecology is reliant upon evolutionary principles.

 

For example -

- Management of wildlife is reliant on predator-prey cycling, which is based on the theory of natural selection.

- The most broadly accepted concept of species - our fundamental unit of biological diversity relies on each species having an independent evolutionary history.

- Choice of drug targets for diseases are centred around the mode of inheritance and selective conservation of the genes encoding them - the design of the annual flu vaccine is fundamentally dependent on evolutionary theory.

- Drug breakthrough by diseases is founded in natural selection.

- Cloning relies on evolutionary principles insofar as donor embryos cannot be too genetically distant from the individual being cloned - which depends on limited evolutionary divergence.

- Epidemiological studies are fundamentally founded in the evolutionary histories of hosts, vectors and pathogens. It is impossible to model future disease outbreaks without understanding the evolutionary history of the relevant units.

- Pesticide resistance (e.g. KDR resistance in Anopheles mosquitoes) is understood through selection.

- Endangered species management has to be conducted in the light of evolutionary principles to maximize genetic variation.

- Management of commerically harvested organisms (like fisheries) is conducted using population genetics - which is founded in evolutionary biology.

 

etc.

[MonDie]

It could be applied to many different scenarios. If we want to understand changes ecosystems have gone through and how they tend to develop, if ecosystems develop similarly under similar conditions and to what extent, how viruses and parasites can travel and survive, rate at which currently declining populations can be reformed after going through bottlenecks, which species are closely enough related to allow for inbreeding with severely depopulated species, etc.

The part about viruses and parasites is mostly in the domain of microorganisms. However, I can see how evolution would be applied if someone was anticipating divergent evolution in a certain species. They could also apply evolution to understand the consequences of a bottleneck on a population.

I made this connection between conservation ecology and evolution after reading Arete's post. I imagine that evolution especially applies in conservation ecology because many conservationists would like to promote the survival of a species in the long-term, even if that means ensuring the survival of that species into a time when humans may no longer exist.

 

It's using the underlying fact of evolutionary similarities to infer results. If not for evolution we would not be able to comfortably assume that the genetic make-up of a mouse is similar enough to a humans to be able to do those sort of tests.

That's a good point because we still don't know exactly how genes and alleles make organisms what they are.

 

More examples are the prevalence of sickle cell anemia in areas with a lot of instances of malaria, lactose intolerance, polydactyly in areas, etc.

That still doesn't show why something's evolutionary history is useful. The knowledge that people have genetic diseases because the genes actually confer resistance to other diseases is useful, but it's still in a totally different area of understanding than the knowledge that people evolved from non-human primates, for example.

 

 

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- The most broadly accepted concept of species - our fundamental unit of biological diversity relies on each species having an independent evolutionary history.

I'm not sure how this is an argument for usefulness of understanding evolution, but I think you might have intended to imply something along these lines.

It's using the underlying fact of evolutionary similarities to infer results. If not for evolution we would not be able to comfortably assume that the genetic make-up of a mouse is similar enough to a humans to be able to do those sort of tests.

That's a good point because we still don't know exactly how genes and alleles make organisms what they are.

 

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- Choice of drug targets for diseases are centred around the mode of inheritance and selective conservation of the genes encoding them - the design of the annual flu vaccine is fundamentally dependent on evolutionary theory.

- Drug breakthrough by diseases is founded in natural selection.

It appears like you're saying the diseases are targeting our drugs, which might be why I don't understand the rest of the sentence or the next sentence.

 

- Cloning relies on evolutionary principles insofar as donor embryos cannot be too genetically distant from the individual being cloned - which depends on limited evolutionary divergence.

This sounds more like applied genetics because nothing is actually evolving in this situation.

 

- Epidemiological studies are fundamentally founded in the evolutionary histories of hosts, vectors and pathogens. It is impossible to model future disease outbreaks without understanding the evolutionary history of the relevant units.

Could you elaborate? This isn't familiar territory.

 

- Pesticide resistance (e.g. KDR resistance in Anopheles mosquitoes) is understood through selection.

See the opening post.

 

- Endangered species management has to be conducted in the light of evolutionary principles to maximize genetic variation.

That's a good example that I wasn't aware of.

 

- Management of commerically harvested organisms (like fisheries) is conducted using population genetics - which is founded in evolutionary biology.

Is this like the above example of species conservation?

[Arete]

I'm not sure how this is an argument for usefulness of understanding evolution, but I think you might have intended to imply something along these lines.

 

Not quite - species form the fundamental unit of biological diversity - which in turn forms the basis for a broad range of biological studies. Given that the concept of species is reliant on evolutionary biology, any study based on species is reliant on evolutionary theory - be it an ecological, disease, population, etc. study.

 

It appears like you're saying the diseases are targeting our drugs, which might be why I don't understand the rest of the sentence or the next sentence.

 

Sorry, poor use of language - when you design a drug to combat a disease, be it a pathogen, autoimmune or other disease, you will design it to target a particular component of the disease, be it a developmental stage, a metabolic pathway, motility, etc. If that trait is not conserved across your pathogen/host/patient, the drug will not work in 100% of cases and select heavily for resistant strains. Your drug will rapidly become ineffective if you don't account for evolution.

 

 

This sounds more like applied genetics because nothing is actually evolving in this situation.

 

Applied genetics doesn't actually make any sense without evolutionary theory - the basic principles like HWE, selection, Ne etc are founded in evolution. What I'm discussing in this example is that if your donor and recipient are too evolutionarily distant, your clone/skin graft/organ transplant will not work. Evolutionary distance is important to consider for any medical or research procedure in which biological material will be transferred from one organism to another.

 

 

Could you elaborate? This isn't familiar territory.

 

Understanding how diseases work means understanding how hosts, vectors and pathogens co-evolve. The management of disease in a epidemiological sense - as was undertaken in response to H1N1 is fundamentally based in population genetics, which is a subfield of evolutionary biology. http://en.wikipedia.org/wiki/Population_genetics

 

 

See the opening post.

 

Pesticide resistance isn't restricted to insects (glyphosate resistance in plants), and dividing organisms up based on whether they are vertebrates or not doesn't really make sense in light of the tree of life - most of the biota of the planet is not vertebrate.

 

 

Is this like the above example of species conservation?

 

Nope. In one example you would model genetic diversity in order to maximize it through say, selective breeding of distantly related organisms. In the management of a harvested population you can use changes in allele frequencies to model reductions in effective population sizes, and thus monitor the sustainability of harvesting.

[Ringer]

I think what both Arete and I are getting at is that, like most of science, if you only look at evolutionary theory as a history it may not seem to have direct applications other than furthering our knowledge. The problem is that evolution is the backbone of modern biology, there is virtually no aspect of biology or medicine that has not been, directly or otherwise, largely influence and furthered from the discoveries of evolutionary theory.

[MonDie]

Not quite - species form the fundamental unit of biological diversity - which in turn forms the basis for a broad range of biological studies. Given that the concept of species is reliant on evolutionary biology, any study based on species is reliant on evolutionary theory - be it an ecological, disease, population, etc. study.

How is the concept of species reliant on evolutionary biology? I know that an animal's species is defined by the boundary to producing viable offspring, but I don't know how the species of a bacteria is determined.

 

 

Sorry, poor use of language - when you design a drug to combat a disease, be it a pathogen, autoimmune or other disease, you will design it to target a particular component of the disease, be it a developmental stage, a metabolic pathway, motility, etc. If that trait is not conserved across your pathogen/host/patient, the drug will not work in 100% of cases and select heavily for resistant strains. Your drug will rapidly become ineffective if you don't account for evolution.

This is along the same lines as antibiotic resistance. I think these all might be examples of antibiotic resistance, but I don't know the precise definitions and categorizations. I conceded antibiotic resistance in the OP (opening post).

 

 

Applied genetics doesn't actually make any sense without evolutionary theory - the basic principles like HWE, selection, Ne etc are founded in evolution.

I had to review HWE (Hardy-Weinberg Equilibrium) and learn about Ne (Effective Population Size) for the first time. I see how the genetics of a population is very much intertwined with theories about evolution.

 

After reviewing the HWE, I derived another equation from it using basic concepts in probability. It was fun! I originally explained it here, but I've edited the post to avoid derailing the thread.

 

I see the value of HWE to ecology. HWE relies on the same ideas that form the basis of evolution, but I'm assuming that an understanding of evolutionary history is probably more useful when one is trying to think of explanations for certain shifts in allele prevalence.

 

What I'm discussing in this example is that if your donor and recipient are too evolutionarily distant, your clone/skin graft/organ transplant will not work. Evolutionary distance is important to consider for any medical or research procedure in which biological material will be transferred from one organism to another.

I always thought evolutionary distance was closely correlated with genetic variance because I've heard of people actually using DNA samples to estimate when the blood-lines of different species had split apart. From there, I assumed that we only needed genetics and not evolution because genetics gave more accurate information than evolution without ever getting evolution involved.

However, I was just reading about a worm called Caenorhabditis elegans. Apparently its genes are very similar to our genes despite it being a worm. Maybe I just don't understand exactly how differences in genomes are measured; maybe similarity and difference can exist simultaneously on different levels. According to sciencedaily, "many of its 20,000 genes perform the same functions as those in humans."

 

 

Understanding how diseases work means understanding how hosts, vectors and pathogens co-evolve. The management of disease in a epidemiological sense - as was undertaken in response to H1N1 is fundamentally based in population genetics, which is a subfield of evolutionary biology. http://en.wikipedia....lation_genetics

That is another example involving microorganisms.

 

 

Pesticide resistance isn't restricted to insects (glyphosate resistance in plants), and dividing organisms up based on whether they are vertebrates or not doesn't really make sense in light of the tree of life - most of the biota of the planet is not vertebrate.

Okay.

 

 

Nope. In one example you would model genetic diversity in order to maximize it through say, selective breeding of distantly related organisms. In the management of a harvested population you can use changes in allele frequencies to model reductions in effective population sizes, and thus monitor the sustainability of harvesting.

Are you saying the end (and therefore the means) is different in species conservation versus the sustainment of harvesting?

Edited July 7, 2012 by Mondays Assignment: Die

[Moontanman]

there were some muslim med students in the uk not so long ago who won an internal dispute with their univerisity over non-attendance of evolution classes.

 

That is truly sad, if your religion taught the flat earth theory (which indeed The Abrahamic religions basically do) should you be allowed to pass if you refuse to study geography? Or that the Earth revolves around the sun? How can you say you have an education with out a basic understanding of reality?

 

 

How much physics does a mechanic need to fix a car? EVolution and medicine can't be so different.

 

Actually quite a bit, if you don't understand the whole action and reaction part, just to name one basic simple aspect of it, you could end up killing yourself while working on a car.

 

There is no excuse for allowing religion to trump reality in school. How can a doctor do something as simple as prescribe antibiotics without understanding the evolution of acquired resistance to the drugs?

 

 

Evolution applies to everything in biology and being a doctor without a basic understanding of biology is unacceptable.

[ydoaPs]

How much physics does a mechanic need to fix a car? EVolution and medicine can't be so different.

 

A LOT, actually.

[randomc]

That is truly sad, if your religion taught the flat earth theory (which indeed The Abrahamic religions basically do) should you be allowed to pass if you refuse to study geography? Or that the Earth revolves around the sun? How can you say you have an education with out a basic understanding of reality?

 

Actually quite a bit, if you don't understand the whole action and reaction part, just to name one basic simple aspect of it, you could end up killing yourself while working on a car.

 

There is no excuse for allowing religion to trump reality in school. How can a doctor do something as simple as prescribe antibiotics without understanding the evolution of acquired resistance to the drugs?

 

 

Evolution applies to everything in biology and being a doctor without a basic understanding of biology is unacceptable.

 

Yes, evolution should be taught.

 

As to the analogy with physics/mechanics, i worked as a fitter for close to a decade and never knew for e.g. kepler's law. Did this affect my competence? i mean, at all? Not really.

 

A LOT, actually.

 

Dammit, i meant in trems of knowledge.

[CharonY]

Just wanted to respond to a point in the OP, evolutionary theories are often less applicable to unicellular organisms as several mechanisms, including horizontal gene transfer but also problems in defining species make it actually harder than for other organisms.

 

That being said, Arete essentially responded to it perfectly, it is the all-encompassing theoretical framework that holds biology together. One may have to dig a bit to appreciate how relevant it really is, but it is necessary as a foundation for almost all areas, from molecular biology (thinking in terms of structure-function relationships, sequence similarities etc), to ecological networks.

[MonDie]

Just wanted to respond to a point in the OP, evolutionary theories are often less applicable to unicellular organisms as several mechanisms, including horizontal gene transfer but also problems in defining species make it actually harder than for other organisms.

 

That's interesting. I asked my Bio teacher how we classify species of bacteria, and he gave an unsatisfactory answer.

 

Maybe I'll understand the significance of evolution soon. I've taken thorough notes on one-fifth of my Biology textbook, and I will continue unimpeded by this forum (note the new avatar).

Edited July 14, 2012 by Mondays Assignment: Die

[Nathan Flinn]

Archaeology, ecology, physiology, and genetics contribute to our understanding of their evolutionary history, then our understanding of their evolutionary history contributes to what?

 

The fields you listed all provide evidence for the theory of evolution and use the understanding of evolution to explain certain observations.

 

Understanding of how anything in the universe works is itself a contribution to what makes humans interesting (to humans). Understanding very fundamental phenomena creates a greater connectivity in the network of knowledge and enables generalizations of the understood principles to phenomena found in other fields of study (even if those fields don't exist yet).

 

I just want to mention two 'cases':

 

1) A method called fMRI has revolutionized not only many basic sciences but also more applied fields such as diagnostics. The method originates from curiosity of minds unconcerned with its potential applications. (These minds were concerned with questions like how atomic nuclei resonate in magnetic field. Understanding of these phenomena had absolutely no obvious contribution to anything practical at the time. We should be glad that such matters were of no concern to the pioneers.)

 

2) Evolutionary algorithms (little programs based on the principles of biological evolution) are used routinely in machine learning, image processing, artificial intelligence, optimization,... Fields such as developmental biology (including "evo-devo") would be baseless without basic understanding of evolutionary principles.

 

This being said, the so called Darwinian evolution is only one manifestation of a more general evolutionary principle (development of brain circuits can be explained by non-Darwinian [or not-so-Darwinian] evolution).

 

Finally, even if winning debates with fundamentalists (wishful thinking) were the only application of understanding of the theory of evolution, it would be worth it.

Edited July 19, 2012 by Nathan Flinn

[too-open-minded]

Personally I believe that evolution applies not only to biological things but is a law of nature that applies to everything.

[Ophiolite]

While many things do indeed change over time and this change is sometimes characterised as a form of evolution, in most contexts evolution refers specifically to some form of biological evolution, involving heritable characteristics mutation, natural selection, adaptation, etc. In this sense then, evolution does not apply to everything and it may be misleading to say that it does.

[too-open-minded]

Well yeah the definition of evolution is the change in allele of a species over a period of time. Although labels can narrow peoples vision and be misleading. Things aren't always as they seem.

 

Personally I think Evolution is the answer to life, nothing special or mystical. I'm just a highly evolved body of matter

 

Just because right now we cant necessarily prove where life comes from, doesn't mean it has an answer "larger than life."

[Ringer]

A paper on using evolution to make semiconductors:

 

http://www.pnas.org/content/109/26/E1705

[Delta1212]

I'd say that it's less a matter of "knowledge of evolutionary theory is an absolute prerequisite to practical advances" and more a case of allowing us to pre-emptively weed out obviously wrong answers and recognize potential issues before they occur.

 

A mechanic with access to a lot of broken cars can learn how to fix them by trying a lot of things and seeing what works. A physicist with one broken car is going to be able to work out what the effect of his changes are before making them and probably figure out roughly where the problem might be based on the effect it has on the operation of the car. It's quite possible they'll both reach the right answer, the theoretical knowledge just makes it a bit quicker and cheaper, and you'll have the added benefit of knowing why your answer worked rather than just knowing that it did.

[Ophiolite]

I would always favour having my car fixed by a mechanic rather than a physicist. I'd be patronisingly sympathetic to anyone who thought otherwise.

[CharonY]

I'd say that it's less a matter of "knowledge of evolutionary theory is an absolute prerequisite to practical advances" and more a case of allowing us to pre-emptively weed out obviously wrong answers and recognize potential issues before they occur.

 

 

 

I feel you may still be missing the point. Let us say, we want to sequence an organism. First of all, we would assume that DNA is the carrier of genetic information. Why? Because evolution.

Then, if we sequence it, we use methods that differentiate the four bases. Why? Because evolution.

The way we then detect open reading frames, deduce protein coding sequences, identify the amino acid sequence thereof and predict functions are all possible under the theoretical framework of evolutionary theories. Without them the approach would have to be radically different. It is therefore not only selector of bullshit (which it sometimes is, but probably not that often in a scientific context) but it is really the foundation of many actual approaches.

[too-open-minded]

Wait did I misunderstand you or did you imply that through the study of DNA and genetics you can use it kind of like physics and make predictictive models to predict the functions of DNA?

 

I probably misunderstood you though lol