Evolution & cancer.

32


Discussion by: Dsquared

Let me start off by saying that I am an engineer – not a scientist or biologist.  This short article is obviously intended to pose a question rather than be an academic paper; however, I hope that it will encourage a new  thought process into the subject of evolution and the possible links with cancer.

Some years ago, I read Richard Dawkins fascinating book – ‘The Blind Watchmaker’ and have often wondered what key events favourably change the human evolutionary process.  Well known processes are the long term development of bi-pedalism.  In his book, Richard Dawkins also describes the gradual development of the eye as a useful tool in humans and animals.  These examples I guess are triggered by the need to become more efficient or obtain an edge on competitors.

But what if a trigger event (on the cell structure) is too rapid for the biological process to adapt?  I am thinking of the deadly external ‘inputs’ to living things such as chemicals and radiation.  These external influences are also well known triggers for cancer – which if my understanding is correct, cause cells to mutate and grow at alarming rates.  The outcome is certainly not a favourable one.

Normally,  new ‘trigger inputs’ from an animal’s environment are handled very gradually in terms of evolutionary change.

My question: Is the body (primarily the affected cells) trying to ‘cope’ with the new situation and shift into a new evolutionary gear?

Has the DNA in people with low sensitivities to cancer been ‘programmed’ over many generations by similar, but less rapid trigger events that modify the DNA and essentially render the cells immune?  Put another way, in susceptible people, are cancerous cells a failed DNA attempt to deal with a rapidly challenging external environment?

A key point in terms of susceptibility is that humans appear to have different sensitivities to cancer.  The well known example of…..” my Grandfather smoked 30 a day and lived until he was 90” comes to mind.

For some people, examples of ‘modern’ challenging external environments are:

  • Man-made chemicals.
  • Drugs (such as cigarettes).
  • Continued exposure to high & low frequency electro-magnetic radiation (ultra-violet, micro waves, power lines)

Again, people with a developed low sensitivity tend not to suffer ill effects , whilst people with DNA that has not come through the same evolutionary process may develop cancers.

I do not know what research has been performed on the occurrence of cancers within the animal population – especially animals that are close to the human environment (pets, farm animals etc).

However, I reason that in the natural world, the count would be low in relation to humans as the animal would be severely disadvantaged and tend not survive to breed.

Cancer is obviously NOT a modern problem, however, this must be primarily attributed to the lack of accurate records and true understanding a hundred years ago.  It would be extremely interesting to obtain mortality statistics from perhaps 500 years ago.  The results may give a further insight into the multi-causal nature of cancer.

To conclude, is cancer a natural and virtually unstoppable side effect connected with the continuing evolutionary process that all living things need to engage with?

Dave Dudley BA

2013

32 COMMENTS

  1. I’m not sure how helpful I can be in answering either of your questions, but I’d like to correct one thing. ‘The body’ will indeed try to cope with any new situation, but it will do so using the immune system and it will fail many times. Occasionally, an organism will carry a mutated gene that will prove useful in the changed situation, but by that time many other ‘bodies’ will have died. It would be wrong to think that an organism will adapt to a threat in any sort of ‘thinking’ way -”what needs to be done to counter this threat?” The organisms that survive will, over time, become the majority of the species type, but there will never have been because anything ‘tried’ to adapt.

    It is quite likely that some people will have greater or lesser sensitivity to certain cancers. Classically, over time, the descendants of some of those people will share a statistic tendency to live longer and thus reproduce more successfully. Except it won’t happen quite like that any more, because we now have successful interventions for many cancers. This means that natural selection will have little to work on.

  2. Yes, life is carcinogenic. Without mutation none of us would exist. Obviously it is not unstoppable however, same as with death (although I think Richard Dawkins would like to disagree…he seems to think death is the inevitable consequence of living and we shouldn’t complain about the fact that we have had our short time in the sun, just because we have been uncomprehendingly lucky), the holding back of entropy is possible…albeit difficult.

  3. These external influences are also well known triggers for cancer – which if my understanding is correct, cause cells to mutate and grow at alarming rates. The outcome is certainly not a favourable one.

    All present day life is descended from a single celled ancestor. Once life became multicellular, cells had to evolve specialist functions with different organs. All human cells have the same genetic material, but the cells of each organ had to be a particular specialist type, with genes to grow other parts of the body suppressed in those cells. They also had to grow organs in a particular place and to a particular size -and then stop dividing and growing – apart from routine replacement of dying cells.

    Cancer is when the regulatory mechanism restraining cell growth and keeping cells in their proper locations is broken.

    The cancer cells are like a vehicle with the throttle jammed open or the brakes disabled. Their fuel consumption and growth just runs wild until they jam up or break other mechanisms in the body – basically acting as very competitive primitive cells dividing and growing independently of bodily controls.

    It is not so much that the mutations which cause variation in populations which natural selection can act on, cause cancer per-se, but that those mutations break growth regulation mechanisms.

    Obviously environments with disruptive carcinogenic chemicals or radiation, are more likely to hit regulatory targets as well as causing genetic changes (damaging or otherwise) generally.

  4. The key thing to understand is the body is no way plots to mutate to deal with a new stress. The reproductive process just makes mistakes from time to time as a side effect of reproduction. Any sort of stress, light or heavy, is going to favour some individuals over others. Unless the stress wipes out the entire species (as his happening to all the large fish species unable to deal with man’s machinations), there will always be a few superior individuals (perhaps still woefully inadequate) for the next generation.

    One of the questions I have yet to dig into is the error rate of different species, and does that evolve over time? I know that HIV has a very high error rate, which is what gives it such excellent drug immunity. It is not even using the error-correcting mechanisms that come with DNA. Does a species that has not changed in a long time evolve a low error rate? I have heard both that cockroaches have a very high and very low error rate. I don’t know which is correct.

  5. before the days of medicine humans could hope to live 30 or so years. seems harsh but it’s more than long enough to become a parent and even ensure there’ll on average be a few grandparents in every community. Cancer is on the increase because most of modern humans lifespan these days is un-natural. the body makes dodgy cells, and cleans them up. as it gets older it starts to lose the battle and enough dodgy cells get a foothold.

    here’s an interesting piece however from Paul Davies. I found it looking for another article suggesting cancer as an early life form but couldn’t remember the title

  6. I think it is also productive to illustrate that the number of cancers that the body successfully eradicates BEFORE symptoms or detection is an estimate at best and unknown at worst.

    It is my understanding that in order for a cancer to develop, two mutations must exist (and persist) in the same cell. One of these errors activates the cell and begins it’s conversion into a precancer and then ultimately a cancer. However, for this to actually become a tumor, the tumor suppressor genes (presumably evolved due to the pressures that the OP is hinting about) must also have an error that causes them NOT to fire up and “squash the uprising”.

    Cancer is, IMO, a naturally and virtually unstoppable side effect…etc… but that does not mean that it is untreatable nor not preventable.

    Also, please keep in mind that when you say the word cancer, you are actually speaking about more than 200 different diseases. The underlying biology is different for each different disease, but the catch all word “cancer” describes all of them (inadequately).

  7. I think the OP is confused. Evolution acts over multiple replicator generations, which in animals virtually always means through generations of discrete organisms. The mutations of genes come about either through exposure to mutagens that induce a change in the atomic structure of the nucleotide bases or due to copying errors during the replication process, but all that does for natural selection is provide the variation needed to “select” between one phenotype over another. The fact that mutation can also cause cancer has nothing to do with evolution by natural selection, because not only does the cancer kill off its victims within one generation, but it does not have any effect other than to randomly kill individuals regardless of inclusive fitness. The body does not evolve to deal with cancer, whether to cope or not, because one body does not evolve in the first place. Nor is cancer a side effect of evolution. It’s simply the possible outcome of certain environmental factors on one body.

    • You are dead on correct! The assertion that an individual is the unit of evolution is the logical fallacy in the OP’s handling of cancer and evolution. The sooner a person understands and puts into practice the fact that populations evolve, not individuals, the better their overall understanding of biology will become.

      In reply to #7 by Zeuglodon:

      I think the OP is confused. Evolution acts over multiple replicator generations, which in animals virtually always means through generations of discrete organisms. The mutations of genes come about either through exposure to mutagens that induce a change in the atomic structure of the nucleotide bas…

      • In reply to #8 by crookedshoes:

        You are dead on correct! The assertion that an individual is the unit of evolution is the logical fallacy in the OP’s handling of cancer and evolution. The sooner a person understands and puts into practice the fact that populations evolve, not individuals, the better their overall understanding o…

        taking the gene as the unit of replication, cancer suddenly looks pretty good in an evolutionary sense, it just has a tendency to reach a dead end in its host but then any replicator that’s too fast for its environment to sustain meets a similar end

      • In reply to #8 by crookedshoes:

        The sooner a person understands and puts into practice the fact that populations evolve, not individuals, the better their overall understanding o…

        Evolution requires a mutating population of replicators and a selection mechanism. But inside every human there is a population of mutants with a selection mechanism. Its called the adaptive immune system. I thinks its not normally referred to as evolution because the adaptive mutations are not passed on to human descendants. If the selection mechanism does not work correctly then populations (of for instance B cells) can evolve that result in a type of cancer (Lymphoma). See https://ash.confex.com/ash/2012/webprogram/Paper48740.html
        http://en.wikipedia.org/wiki/Somatic_hypermutation

        • I see and understand your point and your links are cool too. I will still point out that the adaptive immune system can be assessed as a population of cells. So, it does get sticky when an individual is made up of populations of cells. And, even stickier when figuring in Richard’s brilliant selfish gene meme. Realizing that individual cells have populations of genes inside them…

          It, however, still is a population that evolves, not an individual. The beauty of this statement is that typically, the scientist gets to define the population. In your example, you have defined the population as the B cells. In Richard’s example, the population is defined as a set of genes. In mine, I was defining the population as “humans”. The overriding issue, though, is that populations evolve, individuals do not.
          In reply to #23 by Logar:

          In reply to #8 by crookedshoes:

          The sooner a person understands and puts into practice the fact that populations evolve, not individuals, the better their overall understanding o…

          Evolution requires a mutating population of replicators and a selection mechanism. But inside every human there is…

          • In reply to #24 by crookedshoes:

            I see and understand your point and your links are cool too. I will still point out that the adaptive immune system can be assessed as a population of cells. So, it does get sticky when an individual is made up of populations of cells. And, even stickier when figuring in Richard’s brilliant selfi…

            I realize its standard teaching that “individuals do not evolve”. This article http://evolution.berkeley.edu/evolibrary/misconceptions_faq.php#a4

            under the heading “MISCONCEPTION: Individual organisms can evolve during a single lifespan”, says

            who wouldn’t want a gene for malaria resistance to come along with a vacation to Mozambique? — evolution just doesn’t work that way. New gene variants (i.e., alleles) are produced by random mutation, and over the course of many generations

            But it IS possible for an individual to gain Natural Acquired Immunity (NAI) to malaria. If you are exposed to enough of it at an early enough age its likely that you have enough generations of random gene mutations occurring in your population of adaptive immune system cells that something has been selected that provides you with resistance to the local malarial parasite. NAI is a fact, but how it works is not so clear, see http://cmr.asm.org/content/22/1/13.full

            Its clear to me that there is a type of evolution going on in Adaptive Immune Systems. Since a human individual is comprised of a population of cells which include those in the adaptive immune system, it seems to me that each human individual is at least in part evolving. I suspect that most scientists don’t like to use the word evolution to describe what is happening in each Adaptive Immune System, because they don’t want anyone to think they hold some kind of Lamarckism. But the admission that individuals partly evolve would I suspect help to concentrate minds on better ways to treat various diseases including cancers.

          • In reply to #25 by Logar:

            But it IS possible for an individual to gain Natural Acquired Immunity (NAI) to malaria…Since a human individual is comprised of a population of cells which include those in the adaptive immune system, it seems to me that each human individual is at least in part evolving….I suspect that most scientists don’t like to use the word evolution to describe what is happening in each Adaptive Immune System, because they don’t want anyone to think they hold some kind of Lamarckism. But the admission that individuals partly evolve would I suspect help to concentrate minds on better ways to treat various diseases including cancers.

            I don’t think any scientist would say that cell populations within the body don’t change in response to selection pressure. As you say the adaptive immune system (and the innate system while we’re at it) is a marvel of response to environmental presure. The issue with Lamarckism is the suggestion of inheritance of these changes. Whilst there is some suggestion of a ‘soft’ neo-Lamarckian system of inheritance, it doesn’t change that the tendency of an organism to respond to differing pressures in whatever way is in itself regulated by its baseline DNA which is relevant to a population and its offspring down the generations – so the fact that an individual can develop NAI is evolution but it doesn’t mean it’s the proximal cause.

          • I think it keeps coming back to the definition of a population. In my experience, populations are defined by the researcher. If you are going to define your population as a group of immune cells within an individual human, then no SINGLE cell evolves. If you define your population as a group of humans, no individual human evolves.

            I am not sure you are clearly defining your population…. If a single human can evolve because the population of b cells inside the human adapts and respond, is the individual human evolving, or is the population of immune cells evolving inside the human??? I know it seems like splitting hairs, and, you are citing credible sources, but the thing is, the concept maintains it’s integrity when the researcher clearly defines the population.

            If you are exposed to enough of it at an early enough age its likely that you have enough generations of random gene mutations occurring in your population of adaptive immune system cells that something has been selected that provides you with resistance to the local malarial parasite.>>

            Here, in your own words, you illustrate the exact point that I am making. So the human individual evolves because the POPULATION of adaptive immune cells undergoes natural selection. I told you that it gets a little sticky; and it does.

            Not wanting to appear patronizing, but, look up that concept of population: the scientist gets to define it. And, as long as you clearly delineate what you are studying and do not conflate it with the next “level” up, you still arrive at the conclusion that individuals do not evolve, populations do. Your own words clearly show this, even if it gets a little muddled in the overall interpretation.

            In reply to #25 by Logar:

            In reply to #24 by crookedshoes:

            I see and understand your point and your links are cool too. I will still point out that the adaptive immune system can be assessed as a population of cells. So, it does get sticky when an individual is made up of populations of cells. And, even stickier when fig…

          • In reply to #28 by crookedshoes:

            individuals do not evolve, populations do

            Straying a bit, that would be the reason the “Gaia” hypothesis of James Lovelock doesn’t fly well with evolutionary biologists, I suppose? Because there’s only one of it?

          • I do not know much about the gaia hypothesis, however, in reading a bit about it, I will say that the ways that it is employed and the people who it works for are (it seems to me) very much focused on the issue of this interaction through the lens of the abiotic forces. It seems that they study the salinity of the ocean and then look at the living things in the ocean.

            I kind of do the same thing only backwards (or are they doing my paradigm backwards?). I have not devoted much time or thought to this way of looking at the world. It is intriguing. I am going to investigate a bit and then, if this thread is still chugging along, I will try to get back to you. Sorry I am not more useful, here, but this is a topic that truly you put on my plate for the first time.

            BTW, thanks for giving me some cool stuff to do!!!

            In reply to #29 by OHooligan:

            In reply to #28 by crookedshoes:

            individuals do not evolve, populations do

            Straying a bit, that would be the reason the “Gaia” hypothesis of James Lovelock doesn’t fly well with evolutionary biologists, I suppose? Because there’s only one of it?

  8. Gary Taubes wrote a book some years back about the history of nutrition science. He included some references to data collected from about 200 years ago which sheds light on the incidence of cancer.

    From what I remember there isn’t much in the way of conventional statistical data. The data sources were in the form of letters to home. Basically Europe was in a colonial frenzy and Europeans had established outposts all over the globe. Surgeons were typically assigned to these outposts, often staffed by young aristocrats who preferred to avoid conventional military adventure.

    Among the heirs of the wealthy making scientific observations was becoming a very popular and acceptable alternative to military heroism, and the environments they found themselves in were very new and strange.

    A common theme extracted from letters and reports home, all over the globe, is that native populations surrounding colonial outposts typically showed few signs of diseases normally associated with those of western colonial background. There were certainly decimations from contagious illnesses, but relatively little in the way of non-infectious and non-communicable diseases. Notably cancer. However this pattern tended to shift with passing decades. So that some 30 years following colonial establishment and significant integration of native populations into the emerging colonial economies the relative rates of non-communicable diseases tended to equalise.

    From my limited understanding about cancer I think it isn’t really any one thing. Living organisms have multiple and incredibly complex moelcular processing pathways, with redundancy and checks and balances. Like aircraft accidents, tumours would be a consequence of multiple failures in multiple systems. It’s reasonable to assume that environmental damage to DNA is continual and possibly random. And that cellular mechanisms would have evolved to be reasonably effective in mitigating this damage. So you have to look both at direct and indirect causes – i.e. failures of damage mitigation processes.

    If the early colonial data Gary Taubes referred to is relevant then you’d be looking for a sudden environmental overload that overwhelms normal human physiological responses. Taubes view is that this overload is probably associated with colonial practises introduced as a consequence of imported food during an outpost’s establishment in an era when refrigeration was not yet established. The high cost of logistics in establishing colonial outposts implies large quantities of imports like flour and sugar and other forms of highly compact and self-preserving foods, in exchange for the timber and other resources initially obtainable from colonial economies. Nutrition was very much an emerging science. E.g. the cure for scurvy was established by the British navy in colonial times owing to the high death rates among ships crew. Solution being lime juice – hence the term ‘limey’ for British sailors of that era.

    The imported foods then became cultural staples in those former colonial areas. Parts of the world that are less impacted by colonialism and less culturally locked into relatively high levels of consumption of highly processed foods are believed to suffer significantly less from non-communicable disease. Though that all changed in the 20th century owing to global warfare followed by the invention of McDonalds etc.

    There’s some promising research now underway involving dietary changes which negatively impact the fuel sources many tumours require, and which may also have a positive impact on the immune processes that would otherwise be impaired from effectively mitigating tumour growth.

    There’s also anthropology research shows that pre-civilisation humans had very high death rates. But mainly from infant mortality or violence and not from accumulating disease. It is now believed that humans living as hunter gathers who survived childhood and the violence of adulthood tended to live to a ripe old age, without the aid of modern medicine. Which might explain a few things about human culture – assuming it’s the most successfully violent adults that tend to reach old age, and therefore who tend to be the ones providing the bulk of the grand-parenting of subsequent generations.

    • In reply to #9 by Pete H:

      There’s some promising research now underway involving dietary changes which negatively impact the fuel sources many tumours require, and which may also have a positive impact on the immune processes that would otherwise be impaired from effectively mitigating tumour growth.

      Somebody close to me has lung cancer and I’ve been sent ‘helpful’ dietary advice along these lines – so far, all I can find are papers on using a ketogenic diet (basically the Atkins diet) to slow disease in mice who have been bred to have brain tumours. Some add a dash of Omega-3 or hyperbaric oxygen if they want to be different. I’ve not found anything specifically claiming to improve the immune response to cancers although it’s been known for a while that cancers evade immune surveillance.

      Unfortunately, most of the stuff put my way has sailed off the deep end (e.g. “Milk causes the body to produce mucus, especially in the gastro-intestinal tract. Cancer feeds on mucus. By cutting off milk and substituting with unsweetened soy milk, cancer cells are being starved”), been distinctly unlikely (“Cancer cell walls have a tough protein covering. By refraining from or eating less meat it frees more enzymes to attack the protein walls of cancer cells…” – ok, I’m being generous there), or merely pseudoscientific (“Cancer cells cannot thrive in an oxygenated environment. Exercising daily, and deep breathing help to get more oxygen down to the cellular level. Oxygen therapy is another means employed to destroy cancer cells” – see my mention of hyperbaric oxygen above)

      The other thing none of them seem to think about is how to get ill people to eat this sort of diet they advocate. – The simple fact is people with cancer need more calories, not less – not easy to achieve with a restrictive and unpalatable diet.

      • The work I heard about involved eating pretty much nothing for an extended period. Probably only relevant to specific kinds and stages of cancer. Presumably people who are severely affected won’t have the bodily reserves to endure any kind of treatment that shocks the body.

        I heard about it last year sometime. A guy in Western USA. Next step was to move beyond mice. Something might already be underway with human experiments. This wasn’t pseudoscience. It was an article on the Australian National Radio health report or science show. It had the potential to double the effectiveness of chemical and radiation treatments. They had another item more recently about intermittent fasting – which seems to have become an infectious virus in itself. Some of the radio station staff found the idea so convincing they’re trying having a go themselves.

        Re the colonial reports mentioned by Gary Taubes. Cancer was just one of many conditions that were regarded as extremely rare in native hunter gatherer populations. Plus pretty much every non-infectious disease from alzheimers through to the end of the alphabet. Which is where the idea that cancer and many other diseases may have a common cause. Yes, anecdotal and not even a mathematically quantified correlation.
        But a significant clue.

        And since metabolic syndrome has become generally accepted it’s known that many of these things really are related. A common cause seems very likely.

        Doesn’t rule out infections either. The common cause may be some kind of impact on immune systems that allows more viral invasions. There’s other clues like the very widespread experience of people on prolonged ketogenic diets not experiencing minor viral infections as frequently as otherwise. I don’t think there’s been any research into that phenomenon yet. I’ve noticed this effect personally. Though it still could be imaginary, or if it’s true it could be some effect on the immune system. Either weakening so that infections occur but without the symptoms (which are mostly the immune response anyway) or the immune system is somehow better optimised.

        In reply to #12 by Docjitters:

        In reply to #9 by Pete H:

        There’s some promising research now underway involving dietary changes which negatively impact the fuel sources many tumours require, and which may also have a positive impact on the immune processes that would otherwise be impaired from effectively mitigating tumour growt…

      • In reply to #12 by Docjitters:

        Didn’t Steve Jobs at Apple piss away most of the last year of his life rejecting mainstream medicine and trying to diet his way back to health?

        And did he not admit at the end that he’d made a f***ing enormous mistake?

        We rationalists need to stamp on woo cancer “cures” as hard as we do anti-vax nutjobs. If not moreso. If you miss a vaccination there’s at least a chance you’ll live, and won’t accidentally kill someone else.

        • In reply to #20 by Stevehill:

          Didn’t Steve Jobs at Apple piss away most of the last year of his life rejecting mainstream medicine and trying to diet his way back to health?

          Jobs had a rare variant of rare cancer – an operable pancreatic tumour. He might have died nonetheless but you can’t waste time with these things…

          We rationalists need to stamp on woo cancer “cures” as hard as we do anti-vax nutjobs. If not moreso…

          Agreed. I’ve known at least 2 kids who were taken to to the USA for “treatment you can’t get in Europe”. Alterantive cancer treatments offer false hope and (unlike most anti-vaxxing) takes away from time left to actually live.

  9. In reply to #6 by crookedshoes:

    It is my understanding that in order for a cancer to develop, two mutations must exist (and persist) in the same cell. One of these errors activates the cell…the tumor suppressor genes…must also have an error that causes them NOT to fire up

    You don’t usually need both – An oncogene acting (dominantly) to prevent apoptosis is enough on its own. Likewise, recessive loss of a tumour suppressor, especially if you are genetically missing a copy already e.g. retinoblastoma.

    That said, having both intuitively sounds like it would speed up tumour gorwth.

    …The underlying biology is different for each different disease, but the catch all word “cancer” describes all of them (inadequately)

    Very true. I’d also mention that ‘cancer’ means a tumour with the ability to metastasise around the body. Many tumours are benign – though they can do plenty of damage and be near-impossible to remove if somewhere inconvenient e.g. the brainstem.

  10. In reply to #9 by Pete H:

    …native populations surrounding colonial outposts typically showed few signs of diseases normally associated with those of western colonial background…

    Not really surprising is it? Different genetics, different environment and selection pressures (for the infectious agents and for the people).

    Parts of the world that are less impacted by colonialism and less culturally locked into relatively high levels of consumption of highly processed foods are believed to suffer significantly less from non-communicable disease.

    Beware the correlation Pete H! Is it not more likely that having been absorbed into a western society, somebody stopped and actually noticed all the cancer going around? Also, certain infectious diseases (which may have been imported) can trigger cancer.

  11. Off on a bit of a tangent: the environment around Chernobyl is unhealthy for humans, but wildlife thrives, I have read. The wildlife doesn’t live long enough to get cancer. A higher mutation rate may accelerate evolution in the vicinity.

    Since developing cancer in later life – after breeding – isn’t something that hinders the passing on of genes, genetic susceptibility to cancer hasn’t got much selection pressure against it. If I’ve phrased that right.

    • The opposite might apply, but only in humans, because of language and larger brains combined with cultural learning and innovation, cancer after reproduction can have a detrimental impact on subsequent generations. Reasoning might be that child-rearing, beyond infancy and with very prolonged childhood dependency (up to age 30+ during massive global recessions), often falls to grand-parents. Take away the grand-parents and the entire social system collapses.

      It may be that there is selection pressure that favours individuals who can tap into cultural memories and skills that reside in the minds of very much older generations, at least as long as they tend to survive to advanced old age in reasonable numbers.

      On the other hand, Popper’s concept of the ‘third world’ of documents and objective theories implies that cultures with libraries might no longer need the original authors physical presence for their knowledge to still be effective.

      In reply to #14 by OHooligan:

      Off on a bit of a tangent: the environment around Chernobyl is unhealthy for humans, but wildlife thrives, I have read. The wildlife doesn’t live long enough to get cancer. A higher mutation rate may accelerate evolution in the vicinity.

      Since developing cancer in later life – after breeding – i…

    • In reply to #14 by OHooligan:

      Off on a bit of a tangent: the environment around Chernobyl is unhealthy for humans, but wildlife thrives, I have read. The wildlife doesn’t live long enough to get cancer. A higher mutation rate may accelerate evolution in the vicinity.

      Since developing cancer in later life – after breeding – i…

      is it unhealthy for humans? the difference between humans and other wildlife is other wildlife failed to abide by the evacuation order.

      some stats…

      • In reply to #18 by SaganTheCat:

        Interesting link, thanks for the info. So, the evacuated area is probably as safe as anywhere, other factors considered? I like the bit about the animals ignoring the evacuation order. Maybe a good place for cats?

  12. This is interesting, and relevant to me, mildly, as two weeks ago I was informed I had bone cancer. Then, after a more thorough look, I was told I didn’t. So for a couple of days I started thinking of when I would go to Montana for my medical marijuana. I told my religious, yet wondeful, wife that I had planned on hoarding pain pills for one eternal nap. That rocked her world, because in her religious sphere, my body belongs to God, it is his gift to me, regardless of how miserable I might become. I did tell her it was my broken down, 1988, Yugo of a body and I would decide when it would be donated to charity.

    That aside, I guess the question of errant cells being a jump start to evolutionary change is relevant. Although cancer is a historical problem, I think it becomes more of a modern issue because people generally live longer. Any possible study of comparison between cancer in 1513 and 2013 might be irrelevant due to questions of longevity and life expectancy. Notice I said might. I would imagine some cancers in 1513 may have formed due to inadequate nutrition and…sanitary conditions. We are told fruits and vegetables help fend off cancerous growth and many of us have more access to these.. I also suspect because of sheer squalor, the people in the middle ages lived in, might have been a carcinogenic in and of itself. Yes, I believe filth can kill in the longterm as well as the short term.

    Where does Evolution fit in? I am not trained in science, but in History. However the Scientific Method and the Historical Method are not dissimilar. Recognize a problem, research, find other research to substantiate, and use that information, in the case of science, to solve a problem. (When used right History can be used to solve problems, or create them.)

    A cancer cell, in and of itself, is a microcosm of evolution. One cell, in a body system changes. It becomes different from the rest. In this case, if the immune system does not destroy the cell and its mutated “offspring” continue to proliferate (we all have cancer cells in us…), then the mutation becomes a hinderance to that system, and other systems through metastasis.

    The benefit of this, if you can call it that, would be the Super Mouse phenomena in which our immune systems evolve and become efficient in stopping all cancer cells before they evolve into tumors. Is this possible? Will we eventually breed out cancer? I can’t even begin to discuss that.

    Overall I think.this whole discussin is interesting, but in my opinion, cancer is not a benefit of evolution.

    On a side note, the pain medication Vioxx was found to be a very potent anti-cancer drug. It worked on a variety o f cancers, even brain tumors and pancreatic cancer. It’s key? It stopped vascular growth in tumors. I’m not a conspiracy theorist, although I do dig the X-Files, but I do find it interesting, just as doctors were prolonging patients lives, some indefinitely, Vioxx gets yanked. Something to think about I guess. If you want a citation for the above: Dr. Judah Volkman, Boston Children’s Hospital.

  13. During your life your body has to cope with disease with the immune system you were born with. If some new disease pops up that you happen to already have a mutation that protects you then you may end up passing on this mutation to more kids than the dead people who don’t have it: evolution. DNA is generally only modified during conception (this is a gross simplification).

    Things that mainly kill you after having your kids, like cancer or senility, don’t cause strong evolutionary changes.

    Cancer, is of course, a natural thing. It is a side effect of our ability to grow and heal throughout our lives.

  14. In reply to #15 by JonZ:

    …The benefit of this, if you can call it that, would be the Super Mouse phenomena in which our immune systems evolve and become efficient in stopping all cancer cells before they evolve into tumors. Is this possible? Will we eventually breed out cancer? I can’t even begin to discuss that.

    Hi JonZ, sorry about your situation – as you allude to, the body has evolved to become very good at stopping tumour growth – alas, never perfect. And since the body is not a closed system (regarding environmental triggers), I suspect Super Mouse will never be…

    …cancer is not a benefit of evolution.

    I think cancer is an unfortunate consequence of having a set of genes that work to preserve and propagate themselves. They don’t ‘think’ about the good of the organism. In fact, I always wondered how comic book mutants with the ‘healing factor’ (like Wolverine and Deadpool) didn’t succumb to cancer given how rapidly their cells must turn over to regenerate. All it would take is one futher mutation and a ‘perfectly’ regenerating cancer cell must be supremely resistant to outside effects – including those from within the same body trying to kill it…

    …the pain medication Vioxx was found to be a very potent anti-cancer drug…It’s key? It stopped vascular growth in tumors. I’m not a conspiracy theorist, although I do dig the X-Files, but I do find it interesting, just as doctors were prolonging patients lives, some indefinitely, Vioxx gets yanked…

    COX-2 inhibitors like Vioxx weren’t being used for primary chemoprevention of cancers – it was an effect noticed in case-control studies. It doesn’t prove that it was the Vioxx that stopped them getting cancer (even if there is a plausible mechanism was to why it might work). It’s being looked into in trials but meanwhile, Vioxx was withdrawn generally because they noticed that those patients on it has a greater chance of heart attack and stroke. The drug licence was for inflammatory pain and the trade-off wasn’t thought to be acceptable.

    Are you saying Judah Folkman found the anti-angiogenic properties or that he hinted at the conspiracy? Would love to see the citation
    if the latter!

  15. You can probably find the answers you are looking for in the special edition of ‘Evolutionary Applications’ journal ‘Evolution and Cancer’ available online here http://onlinelibrary.wiley.com/doi/10.1111/eva.2013.6.issue-1/issuetoc

    Example quotes from the articles:

    tumors can be viewed as collections of individuals (cells) that accumulate
    genetic and epigenetic changes, and through their interactions
    with the environment (selection), adaptively evolve.


    >
    cancers should be viewed both as genetically and phenotypically heterogeneous
    populations within individuals (Marusyk and Polyak
    2010) and as different ‘species’ between individuals (Merlo
    and Maley 2010; Gatenby 2011).

    While individual cells may evolve a probability of symmetric division value of 1, they are not expected to remain there. New mutations arise that introduce smaller values.

  16. Cells have many proteins which work as controlling systems, some of which are the p53 and Rb genes. Remember that rapid replication isn’t the only characteristics a cancerous cell has. The other five characteristics of cancer cells are important write down for the sake of the debate and your questions.

    1) They resist inhibitory signals which may stop their growth
    2) They resist apoptosis (programmed cell death)
    3) They stimulate vessel growth which gives these cells nutrients and oxygen
    4) They can multiply forever
    5) They invade local tissue and can create metastases
    and
    6) They stimulate their own growth (which you already brought up in your post)

    Now here are the six hallmarks for cancer cells. As you may or may not know a cancer cell must have all these six hallmarks to be able to call itself for a cancer cell. If it lacks one or two of the hallmarks/characteristics it is called a tumourcell.

    If we say that in the beginning of life there were only replicators we can assume that this replicators could replicate in different rate. The ones who replicated slowly would get outnumbered from the ones who could replicate in an enormous rate. But the ones who replicated fast had a shorter lifespan and therefore more “sore” to environmental factors. In the beginning these replicators replicated randomly but when a random mutation occurred these replicators could now replicate by transcription signal which means that a replicator could begin to replicate only if another subunit bind to it. These new types of replicators survived by natural selection and were much better than the randomly replicating replicators. This was the first type of controlling system and with time as the replicator accumulated into more complex “replicators” such as DNA and RNA more complex controlling systems had to be made.

    In cancer wether it is cause by environmental factors or if it is sporadic there is always a problem with these controlling systems. The replicator who in the beginning of life did replicate fast has now also evolved and therefore a cancer cell can resemble very well a rapid replicator in the beginning of life but the difference is that as life became more complex and more controlling systems were “introduced” the more unlikely it became to develop cancer, which means that cancer was much easier to get billions of years before than what it is today. Evolution has made it more difficult for a replicator (the molecular functional unit of a cell is a replicator, the DNA) to turn into a rapid replicator.

    The word replicator which I am using here is used in Richard Dawkins book “The selfish gene”. I decided to use that word because it fits cancer so well.

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