Evolution News

Evolution: Loss of function mutation helps prevent heart attacks, say researchers

Spread the love

Apparently, heritable loss of a gene that spikes triglyceride levels plays a role in preventing heart attacks.

Experts differ in their estimates of how many Americans might be candidates for a triglyceride-lowering drug. If the eligible group included all adults with triglyceride levels of 200 or more — the normal level is 150 or less — that would mean about 20 percent of adult Americans. If it were just those with the highest levels, above 500, then 2 percent to 3 percent of adults would qualify.

The discovery announced on Wednesday was hinted at in 2008 in a much smaller study of the Amish conducted by researchers from the University of Maryland’s medical school. One in 20 Amish people has a mutation that destroys a gene, involved in triglyceride metabolism, compared with one in 150 Americans generally. The scientists were intrigued but did not have enough data to nail down the gene’s role in heart attacks.

One gene, APOC3, stood out. The scientists found four mutations that destroyed the function of this gene. The Amish study had discovered that people with such a mutation could drink a big, rich milkshake, loaded with fat, and their triglyceride levels did not budge. For everyone else, they spiked. The new studies show what that means for people’s health.

“Those who carry the gene mutations have a 40 percent reduction in triglyceride levels and a 40 percent lower risk of heart disease,” said Dr. Sekar Kathiresan of Massachusetts General Hospital and the Broad Institute. He is the lead researcher on the gene project.

Is this Darwinian evolution in action? No, because loss of function is the opposite of gain in function, which is what Darwin’s theory (natural selection acting on random mutation) proposes to explain.

Loss of function is a form of evolution, but is resources are very limited. The problem is, as Jonathan Bartlett kindly writes to say,

If we destroy enough genes we can make a human! If we burn enough buildings we can make a city, and if I comment out enough code I can write a program. I can build a company if only I can fire enough employees, and I can invent new machines by taking an axe all my prototypes.

Something is wrong with that picture, wonder what?

See also: Edge of Evolution

Follow UD News at Twitter!

29 Replies to “Evolution: Loss of function mutation helps prevent heart attacks, say researchers

  1. 1
    Acartia_bogart says:

    “Is this Darwinian evolution in action? No, because loss of function is the opposite of gain in function, which is what Darwin’s theory (natural selection acting on random mutation) proposes to explain.”

    In fact, this is not likely natural selection at all because whether or not the gene is present, it doesn’t show negative or positive affects until after the individual has passed the peak age for reproduction. At best, this is probably an example of neutral selection or drift.

    But what about the random mutations that have allowed two different bacteria species to break down nylon. Surely this is an example of natural selection working on random mutations to create a function that didn’t previously exist? Or Lenski’s experiments that have demonstrated the appearance and selection of new function?

  2. 2
    ppolish says:

    a_b, how does “breaking down nylon” help in reproduction?

  3. 3
    Acartia_bogart says:

    “how does “breaking down nylon” help in reproduction?”

    It makes an abundant food source available to those that have this function. For bacteria, this results in increased growth (ie, reproduction) rates. If you doubt that an abundant food sources will result in increased reproduction I invite you to conduct a very simple experiment. Fill two bowls with dechlorinated water. Spike each with a couple drops of pond water. Add some phosphorus (phosphate based soap will work) to one and place them both in the window. One if these will quickly turn very green, the one with the extra food (phosphorus).

  4. 4
    ppolish says:

    Nylon is a man made design. Would nylon eaters be considered unguided random Natural Selection or guided nonrandom Artificial Selection?

  5. 5
    Joe says:

    Acartia_bogart:

    But what about the random mutations that have allowed two different bacteria species to break down nylon. Surely this is an example of natural selection working on random mutations to create a function that didn’t previously exist?

    How was it determined that the mutations were random, as in chance, events?

    Or Lenski’s experiments that have demonstrated the appearance and selection of new function?

    What new function? The bacteria already had the function of digesting citrate. So you must be talking about the ability to get the citrate through the membrane in an aerobic environment so that in can be digested.

    How was it determined those mutations were random, as in chance, events?

  6. 6
    Joe says:

    News:

    Is this Darwinian evolution in action? No, because loss of function is the opposite of gain in function, which is what Darwin’s theory (natural selection acting on random mutation) proposes to explain.

    Yes it is/ could be Darwinian evolution in action as Darwinian evolution is OK with the loss or gain in function. As long as it isn’t fatal or severely detrimental it has a chance of getting through the filter.

    As a matter of fact Darwinian evolution is very good at explaining loss of function, deformities and disease. 😎

  7. 7
    ppolish says:

    Nylon was created by design. The nylon eaters very existence depend on that design.

    “Of course our pond is fine tuned for our existence. If it wasn’t we would not he here. Yes, this fine tuning is incredible. Maybe there exists a vast Multipond?”

    Right about the Multipond. Wrong about the creator.

  8. 8
    Piotr says:

    How was it determined that the mutations were random, as in chance, events?

    There is no evidence to the contrary, so the most parsimonious hypothesis is that the mutation was purely accidental, like winning in a lottery. If you think it was guided, it’s up to you to prove it and demonstrate the mechanism (completely unknown to science so far) by which the bacterium might design an appropriate enzyme for a given substrate, and back-translate it into DNA. It’s an extraordinary claim, and extraordinary claims require extraordinarily solid evidence.

  9. 9
    Piotr says:

    Nylon was created by design. The nylon eaters very existence depend on that design.

    This is pathetic. Bacteria don’t care where the stuff comes for, as long as they can break it down and feed on the products.

  10. 10
    Joe says:

    Piotr:

    There is no evidence to the contrary, so the most parsimonious hypothesis is that the mutation was purely accidental, like winning in a lottery.

    Thanks for proving that you don’t have any methodology. And just how is that parsimonious? How many just-so accidents were required?

    If you think it was guided, it’s up to you to prove it…

    And yet you just get to baldly declare they are random.

    demonstrate the mechanism (completely unknown to science so far) by which the bacterium might design an appropriate enzyme for a given substrate, and back-translate it into DNA.

    No, no one has to demonstrate your strawman. Evolutionary and genetic algorithms are known to us and both demonstrate the power of evolution by design.

    Saying that nylonase arose purely by accident is an extraordinary claim and extraordinary claims require extraordinary solid evidence.

  11. 11
    Joe says:

    Piotr:

    Bacteria don’t care where the stuff comes for, as long as they can break it down and feed on the products.

    That is exactly what I have been telling you.

  12. 12
    Joe says:

    correct formatting:

    Piotr:

    There is no evidence to the contrary, so the most parsimonious hypothesis is that the mutation was purely accidental, like winning in a lottery.

    Thanks for proving that you don’t have any methodology. And just how is that parsimonious? How many just-so accidents were required?

    If you think it was guided, it’s up to you to prove it…

    And yet you just get to baldly declare they are random.

    demonstrate the mechanism (completely unknown to science so far) by which the bacterium might design an appropriate enzyme for a given substrate, and back-translate it into DNA.

    No, no one has to demonstrate your strawman. Evolutionary and genetic algorithms are known to us and both demonstrate the power of evolution by design.

    Saying that nylonase arose purely by accident is an extraordinary claim and extraordinary claims require extraordinary solid evidence.

  13. 13
    Piotr says:

    Thanks for proving that you don’t have any methodology. And just how is that parsimonious? How many just-so accidents were required?

    One accident may be enough, like a single indel causing a frameshift mutation thanks to which a new protein is produced — one that happens to break the β-amide bond. Unlikely? Yes, but less unlikely if you run several quadrillion parallel trials every two hours. One of them may succeed. If not, bacteria will go on feeding on their usual favourite substrate, or perhaps accidentally develop another enzyme which happens to degrade some other stuff released by the factory.

    Evolutionary and genetic algorithms are known to us and both demonstrate the power of evolution by design.

    You don’t know much about evolutionary and genetic algorithms if you think they look at the problem and “intelligently design” a solution. They wouldn’t be called “evolutionary” or “genetic” if they did.

  14. 14
    ppolish says:

    Piotr, nylonase owe their existence to the invention of nylon. Nylon never invented, nylonase never exist.

    Natural Selection thriving on Intelligent
    Design. Mountains of evidence actually.

  15. 15
    Joe says:

    One accident may be enough, like a single indel causing a frameshift mutation thanks to which a new protein is produced — one that happens to break the ?-amide bond.

    And you don’t have any justification for calling it an accident.

    Evolutionary and genetic algorithms are known to us and both demonstrate the power of evolution by design.

    Piotr:

    You don’t know much about evolutionary and genetic algorithms if you think they look at the problem and “intelligently design” a solution.

    Non-sequitur. You don’t know anything about evolutionary and genetic algorithms if you think they aren’t designed to solve specific problems and do so by design.

    They wouldn’t be called “evolutionary” or “genetic” if they did.

    They aren’t called unguided or blind watchmaker because they are guided and goal-oriented

  16. 16
    Acartia_bogart says:

    Ppolish: “Piotr, nylonase owe their existence to the invention of nylon. Nylon never invented, nylonase never exist.

    Natural Selection thriving on Intelligent
    Design. Mountains of evidence actually.”

    I certainly hope that you are joking. Otherwise you are saying that any experiment designed to test evolution is actually demonstrating ID because the experiment is designed.

  17. 17
  18. 18
    ppolish says:

    a_b, is the term “Designer Bacteria” a misnomer? Or can man actually design them?

    Darwin intuited Natural Selection from observing “Artificial Selection”. What would Darwin intuit from observing “Artificial
    Design”?

  19. 19
    Acartia_bogart says:

    Ppolish, what artificial design. We are talking about bacteria in a waste pond. What is designed about this? They simply observed the fact that some of the bacteria in the pond developed the ability to eat nylon.

    This is natural selection. Pure and simple. The fact that humans inadvertently created the environment that resulted in the evolution doesn’t mean that it was designed. Any more than the oxygen atmosphere created by the evolution of photosynthesis was designed.

  20. 20
    ppolish says:

    a_b, google “designer bacteria” or read “Synthetic Biology” wiki.

    Why would a pond be different from a lab? Man made bacteria are still man made. Even if he makes them by accident – it was not random. There is design involved.

  21. 21
    Acartia_bogart says:

    Polish: “Why would a pond be different from a lab? Man made bacteria are still man made. Even if he makes them by accident – it was not random. There is design involved.”

    Again, are you serious? Any natural selection observed as the result of human activity is “designed” because humans have intelligence? Are you seriously trying to argue this point? You do know that other “non intelligent” species have had a far greater impact on the environment, and natural selection, than we ever have, or are likely capable of having? We’re those designed as well?

  22. 22
    ppolish says:

    a_b, Synthetic/Designed critters are starting to show up on the vaunted Tree of Life. Man Made popping up way more often than Nature Made these days…

    http://synthetickingdom.wordpr.....e-of-life/

  23. 23
    willh says:

    “… what artificial design. We are talking about bacteria in a waste pond. What is designed about this? They simply observed the fact that some of the bacteria in the pond developed the ability to eat nylon.

    This is natural selection. Pure and simple.”

    No doubt that natural selection could be involved. However the mechanism that has allowed the bacterium’s initial representative the ability to digest nylon, before natural selection gets to work it’s magic, is in question.

    Random mutation seems highly questionable in view of the odd’s suggested by Joe’s #17 reference, and an automatic default to unobserved random events, circumvents what Poitr suggested previous: that “extraordinary claims require extraordinarily solid evidence”.

  24. 24
    Ho-De-Ho says:

    Hello all. Just thought I’d chip in a ha’penny’s worth of observation on this discussion.

    It seems to me that there is some common ground between both camps (ID and NDE)regarding Nylonase. That is, Nylonase has mutated,let us say randomly, and chanced upon the key to turning nylon into a tasty treat. Natural selection then favours the small fellas particularly while there is a nice deep pit of nylon about or a drawer load of stockings.

    The difference in the camps is a question of mechanism for this natty mutation. Is it:

    a) A completely random mutation brought about through a copying error in bacteria replication which so happens to confer an advantage upon the bugs.

    Or is it:

    b) A random mutation brought about through a programmed response mechanism to environmental change. Or (as curious as this may initially sound, a designed random mutation).

    If I may flesh out option B for clarity’s sake.

    Suppose a person wished to use my bank card but did not have my PIN code. Assuming my bank didn’t intervene, imagine that this person placed my card inside a device that generated at random, 4 digit figures at a rate of one per second, never repeating the same combination of digits. When it lands upon my PIN code then it will access my account. There are 10,000 possible codes.

    At that speed, the device is going to get into my account in under 3 hours.

    The actual numbers that the device comes up with are totally random. It has no conscious awareness of what it is doing, nor is it intuitively trying to figure out some cunning way to the correct number. It is merely pulling the lever and watching the dials spin, until one lands on the jackpot.

    In this sense the device has arrived at the solution randomly. But, and this is nub for the ID crowd I think, the system was specifically designed to find a solution through random number generating.

    Is this what is going on in the case of Nylonase? Is it a total fluke of replication in the bacterial genome causing the solution, or is there a section of the genome geared (pre-designed) to randomly mutate in response to environmental needs?

    Something similar, I believe, is found in the immune-system response. There is a definite section of DNA that gets busy producing random variations for T-cells until one with the correct receptor to fit the invading bugs is chanced upon. The entire genome of a person does not start mutating, but rather a particular section, which seems to be set just for this purpose.

    This sets up for some good scientific investigation. Does Nylonase mutate in specific hotspots or is it arbirarily across the whole spectrum.

    I have no idea of the answer to that, but I would suspect that if it has its own ‘random-mutation-generator’ then the ability to digest nylon should be reached quite rapidly once the bacteria are introduced into its environment.

    A feature like this could also serve a very valuable purpose for all life on Earth. It may assist in preventing build up of rubbish. What other creatures cannot eat or use, like plastic for instance, bacteria may be able to slowly eradicate. I have heard that tests were done on bacteria to see if they could consume toxic waste. I don’t know what the results were though. In fact does anybody know if bacteria can use plastic as a food source?

    I write this little ditty, neither to attack nor defend any position. Those who hold to an anti-ID point of view may reject what I have put here, which is fine by me and I respect that stance. But, perhaps this may help them in seeing where those who hold to an ID view are coming from.

    One caveat. I may have totally got the wrong end of the stick for the ID team, in which case they should correct me as I would not wish to misrepresent them. My comments are based upon what I have understood from the discussions on these boards over time.

    Thanks.

  25. 25
    johnnyb says:

    Ho-De-Ho –

    I think you are a little incorrect on your characterization of the ID position. Instead of viewing it as a random search, imagine instead that I know that the person whose card I am using uses relatives’ birthdays as PIN codes. It then cycles through *those* numbers randomly, rearranging them and so forth. That could probably produce the valid PIN code in seconds or minutes. So, rather than a random search, it is a constrained random search. The organism knows something about what it needs, and then proceeds to search *that* space.

    Along those lines, you might be interested in an old paper I wrote on what it means for a mutation to be random, and a newer paper I wrote on not-quite-random mutations. You also might be interested in a short YouTube video I did on the subject.

  26. 26
    Acartia_bogart says:

    “b) A random mutation brought about through a programmed response mechanism to environmental change. Or (as curious as this may initially sound, a designed random mutation).”

    Yes, we call the environmental trigger a mutagen.

    This sounds a little like clutching at straws to try to explain something that you are uncomfortable with. Mutations are a normal fact of life. In truth, they are not completely from a statistical point of view. There are specific sites in the genome that are more prone to mutations. But that is not the same as saying that they are directed. Sometimes the outcome is positive, sometimes it is negative and sometimes it is neutral.

    And to try to suggest that the nylonase mutation was somehow pre-programmed begs the question of how you can pre-program an organism the respond to a compound that is not found in nature.

  27. 27
    Ho-De-Ho says:

    Thank you for your correction johnnyb. You have expressed it far more succinctly than I managed to.

    I did intend to convey they idea of a constrained random search, in that the device was a specific tool designed to happen upon a solution by using random rolls of the dice.
    Does Nylonase possess its own kind of in-built PIN code device specifically for shuffling limited sections of its genome about to find a solution.

    However, you have stated it more accurately. Much appreciated.

    I will look at your paper and video later, I assure you. Right now though, the old homestead is filling up with chums and chumettes all wondering whether the Iranian football team can land a surprise on the Argentinians in the World Cup.

    Thanks

  28. 28
    willh says:

    Ho-De-Ho:
    “Right now though, the old homestead is filling up with chums and chumettes all wondering whether the Iranian football team can land a surprise on the Argentinians in the World Cup.”

    Pity for them as they very nearly did!
    Then there was Lionel Messi.

  29. 29
    johnnyb says:

    Acartia_bogart and Ho-De-Ho –

    The way that you preprogram something for something that doesn’t exist yet is to make it modular, and to have evolution be parameterized.

    This is evidently the case for Nylonase. The mutation rate *within* the Nylonase genes was so high that, if that same mutation rate would have existed in the rest of the genome, the genome would be swiss cheese. Also, there exists in the spot where the frameshift happened, an open reading frame that works in *every* frameshift position. In other words, it is specifically geared to shift frames and do different jobs.

    More examples of modularized genetics are available in my papers referenced above. You might also be interested in two old UD posts I wrote: Cut-and-Paste DNA and Tuning Knobs in the Genome.

Leave a Reply