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Author | Topic: Lack of random environments | |||||||||||||||||||||||||||||||||||||||||||
AZPaul3 Member Posts: 8513 From: Phoenix Joined: Member Rating: 5.3
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What I find so remarkable is that the pool of available mutations is so useful. That they successfully match up with the environment as often as they do. Which is not all that often. How many species have failed? Did you know that almost half of all human conceptus are spontaneously aborted due to genetic mutation? Another 10% never come to term for the same reason. 60% of all humans ever created never get to live. That's just humans. Multiply by every species that ever lived and every would-have-been species that never made it. Very few mutations are neutral and even fewer are beneficial. But the ones that are beneficial make all the populations. If a species does not have the necessary fitness in some environment it does not last and is usually replaced by something that will. The result is the appearance that mutations have come on the scene in just the right places at just the right times. All the failures are never seen and never considered.
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Dr Adequate Member (Idle past 284 days) Posts: 16113 Joined:
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The observations that we see are virtually organisms getting exactly what they need to survive better, when they need it. Incidentally, if you're going to pretend that all mutations are beneficial, how about you go and argue with the creationists who pretend that all mutations are harmful? Come back when you've sorted out between you which mistake you'd like to make.
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Dogmafood Member (Idle past 348 days) Posts: 1815 From: Ontario Canada Joined: |
Which is not all that often. How many species have failed? Most of them I understand but how many successful gene mutations were required to produce a human? All those extinct species had a long string of successful mutations before they failed. So I wouldn't say that it doesn't happen all that often. As a % of total mutations the number of successful mutations is small but as a quantity the number is immense.
The result is the appearance that mutations have come on the scene in just the right places at just the right times. Yeah I get that. Life has a scatter shot approach to finding the right combinations. Always firing and only occasionally making the target. It is like one of those electronic lock decoders that goes through all of the possible combinations until it hits on the right one. With the added complexity that the combination is changing while the search is running. As life becomes more complex does the pool of all possible mutations increase and thereby increase the potential to hit on the right combination for a new or changed environment? Or are the survival requirements of a more complex phenotype more exacting? Do you think if we were to start firing lichens and bacteria at the moon that we would eventually get one that sticks. If there is an environment for every mutation is there a mutation for every environment?
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Dogmafood Member (Idle past 348 days) Posts: 1815 From: Ontario Canada Joined: |
Take this fish that has started to eat birds from the shore for example. Say the behaviour is successful for an extended period of time or, in other words, that the environment remains stable. Is it only a matter of time before one of these fish mutates some fins that work more like feet or gills that work more like lungs? Given enough time will those mutations always come along?
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AZPaul3 Member Posts: 8513 From: Phoenix Joined: Member Rating: 5.3 |
Lots of questions, and good ones.
As life becomes more complex does the pool of all possible mutations increase and thereby increase the potential to hit on the right combination for a new or changed environment? Or are the survival requirements of a more complex phenotype more exacting? You can have some pretty complex creatures on a relatively small genome and some simpler ones on larger genomes. Human vs amoeba as an example. Obviously the larger the genome the more chance for mutation. I'm not sure how much of the Polychaos dubium 670 billion base pairs represent active coding allels, but I would think it could take on many more mutations than a human (2.9 billion bp) that are in non-coding portions thusneutral. So, no, complexity does not necessarily increase the genome nor increase the chance of a random beneficial hit.
Do you think if we were to start firing lichens and bacteria at the moon that we would eventually get one that sticks. We're pretty good at hitting the moon with anything we throw at it. Given the lack of atmosphere, exposed to the solar winds, I don't think anything organic from this planet could survive up there.
If there is an environment for every mutation is there a mutation for every environment? I assume you mean where a mutation would be beneficial. No. I can imagine there are mutations in "highly conserved" genes that are fatal in just about every environment. And "mutation for every environment" indicates that the environment causes specific mutations? No. That Lamarckian stuff went out many decades ago.
Take this fish that has started to eat birds from the shore for example. Say the behaviour is successful for an extended period of time or, in other words, that the environment remains stable. Is it only a matter of time before one of these fish mutates some fins that work more like feet or gills that work more like lungs? Not at all, unless, I suppose, we're talking an infinity of time in which case everything will happen. No, there is no foretelling any features or mutations.
It is like one of those electronic lock decoders that goes through all of the possible combinations until it hits on the right one. With the added complexity that the combination is changing while the search is running. I like this. Neat analogy. Unfortunately there is a huge number of digits and symbols on the dial and the length of the combination is unknown. And when you hit on a combination and open the door you often find another lock, so you have to open that one before the one you just opened closes you out. Seems hopeless until you remember there are billions upon billions of trials. Something is bound to hit, but there is no way of knowing what it will do. Edited by AZPaul3, : No reason given. Edited by AZPaul3, : usual Edited by AZPaul3, : I am never going to get this right.
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Taq Member Posts: 9970 Joined: Member Rating: 5.6
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The observations that we see are virtually organisms getting exactly what they need to survive better, when they need it. I'm sure trilobites and dinosaurs would be surprised to hear that.
It mirrors the smaller adaptions we see all around us, like the ability to tan, the occurrence of blisters when our skin needs more protection, muscles that grow stronger when we need them to do hard work, lungs that getting better at breathing when we need to run longer. None of those have anything to do with mutations.
Random mistakes hardly seems an adequate explanation for this being so. And yet that is exactly what we observe: Luria—Delbrck experiment - Wikipedia REPLICA PLATING AND INDIRECT SELECTION OF BACTERIAL MUTANTS - PMC These experiments are over 60 years old. That is how long we have known that beneficial traits are produced by random mutations. Perhaps it is time you caught up to the rest of us?
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caffeine Member (Idle past 1024 days) Posts: 1800 From: Prague, Czech Republic Joined: |
In a sense, I guess. Consider the case where the environment includes people who are breeding for the bizarre trait in question. For example a fruit fly with antennapedia is presumably less fit in the wild than one without, but it is more fit when its environment is rich in geneticists wanting to study HOM-C genes. Or for a more everyday example, look at some of the domesticated animals and plants we've produced. We've produced all manner of beast completely incapable of surviving in the wild - to serve as more effective foodsources, to perform some task for us, or just because we think they look cute. Many carry traits that would be catastrophic in most environments and heavily selected against, but they exist in a very unusual environment where the primary selective factor is human intervention. We've even bred organisms completely incapable of independent reproduction but, in the very specific environment of, for example, a pigeon-fancier's coop, they're the fittest organisms.
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caffeine Member (Idle past 1024 days) Posts: 1800 From: Prague, Czech Republic Joined: |
No. The moggy is foggy. All mutations are random in their formation. All mutations are beneficial, neutral or detrimental in respect to fitness. Alfred's way of putting it was exactly correct - mutations are random in respect to fitness. This is what we mean when we talk about random mutations. The processes which cause mutations may well be deterministic and predictable if we had sufficient knowledge, and we know that they are more likely to happen in certain conditions - being bombarded with radiation or exposed to mutagenic chemicals, for example. The randomness is in the sense that you cannot predict what mutations will occur by knowing what would make the organism more fit - mutations happen randomly with respect to fitness.
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AZPaul3 Member Posts: 8513 From: Phoenix Joined: Member Rating: 5.3 |
The randomness is in the sense that you cannot predict what mutations will occur by knowing what would make the organism more fit - mutations happen randomly with respect to fitness. And so it is. I stand corrected.
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Dogmafood Member (Idle past 348 days) Posts: 1815 From: Ontario Canada Joined: |
And "mutation for every environment" indicates that the environment causes specific mutations? No. That Lamarckian stuff went out many decades ago. Using this definition quote: Is there not plenty of evidence to indicate that the behaviour of the mother will influence the genetic make up of the child? Like alcohol or drug use or exposure to lead. The 'mutation for every environment' thought was more toward the idea that if there is such a thing as infrared light then there is a genetic formula to exploit the fact. Or telepathy for example. Our brains produce electric fields that can be detected. Is it conceivable that there a genetic formula that would enable a creature to detect those fields?
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AZPaul3 Member Posts: 8513 From: Phoenix Joined: Member Rating: 5.3 |
Is there not plenty of evidence to indicate that the behaviour of the mother will influence the genetic make up of the child? Like alcohol or drug use or exposure to lead. The genetic make up of the child is already set in this case. The environment during development, drugs alcohol, disrupt the developmental processes the genome is trying to accomplish. The environment can change the genome in that it can destroy what was there and what would have been developed. Think thalidomide. But if the child survives these effects are not passed on. Usually. Lamarckism is more a blacksmith passing on his developed arm strength acquired from his work to his children. There is no mechanism for the traits acquired during life (strong arms, callused feet, tattoos) to in any way change the genome in your somatic cells. You were born with a set genome and, assuming you don't get your balls too close to a hunk of uranium, portions of that is what will be passed on ... intact, just the way you received them. Usually. Make allowances for cosmic rays and things like copy errors in the somatic cells.
more toward the idea that if there is such a thing as infrared light then there is a genetic formula to exploit the fact. One could say that in the grand set of all possible combinations of phenotypic features using infrared may be advantageous in some environments. So some combination of mutations over time might be found to accomplish this feature. Whether or not it actually develops is a whole other matter. Just because a phenotype (and the mutation stream to make it happen) can be imagined does not make that capability available to this world. It's just a "well maybe if everything worked out just right" kind of thing ... which seldom actually happens.
Is it conceivable that there a genetic formula that would enable a creature to detect those fields? Conceivable? Probably. Viable? Probably not. Genetics works with what is there, not with what might be. Edited by AZPaul3, : No reason given.
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