[quote]Aragorn wrote: Mattlebee wrote:
The four building blocks of DNA (or RNA) aren’t especially complex and are just variations on a theme anyway. A single strand of DNA will spontaneously form a double-helix with another (complementary) piece of DNA (or RNA) thereby becoming more stable. Stability is a requirement for continued existence. I think someone else posted a link to an experiment where scientists had made some of the building blocks through simple spontaneous chemical processes.
I have to ask whether you hold a degree in a biochemistry[/quote]
Yes I do.
I wasn’t talking about the origin of life per se, just pointing out that in a situation where you have a mixture of molecules, those that are more stable and those that are able to be replicated will increase their presence. DNA’s greater stability than RNA is why it is the storage molecule for our genes and this comes simply from its molecular properties. Likewise, DNA (and RNA) will fold and base-pair to form stable structures all by itself, so there need be no guiding hand.
Ah, well these are different. I was talking about big statements that seem to anyone to be implausible e.g. “How could something as complex as the eye just spring into existence by random chance.”
Such statements are designed to trumpet the obvious implausibility in order to advance an alternative position. They’re not detailed theories that require discipline-specific knowledge to notice they might be implausible in reality.
[quote]Mattlebee wrote:
It’s not evolution if it’s arbitrary. It’s also not a random process if the cutoff number has been CHOSEN. Some sexual selection can appear to be arbitrary in its origins, but ultimately there is choice involved.
Survival is what matters and since the majority of random mutations in genes will produce deficient proteins, the majority of mutations will cause the death of the organism (often before birth). The set of random mutations therefore strongly overlaps the set of fatal mutations, but only slightly overlaps the set of advantageous mutations. It is therefore a biased, not random, process.
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The problem here is that your set is not collectively exhaustive. You simply mention fatal mutations and advantageous mutations. We also have non-fatal, non-advantageous mutations and non-fatal, disadvantagous mutations. Furthermore, a mutation may be fatal, but not to the point where fatality occurs before reproduction. After all, the only requirement of natural selection is that the individual be able to breed and pass on his genome. In other words, it is not an either/or game. So, while natural selection may show bias towards those genetic mutations that do not cause death before reproduction, we still see randomness in evolution.
Let us only consider the subset of non-fatal mutations. We may still see an apparent bias towards advantageous mutations, but we then must ask what makes a mutation advantageous. For example, it is clearly advantageous for a giraffe to be tall because it can reach higher trees than any other herbivore. If this is true, we next must ask whether some trees are randomly taller than others, for the varying heights of trees is the only thing that makes height advantageous for a giraffe. Was there a bias in place that led to trees getting taller? One could argue that some species grew taller because there was too much competition on the ground. Does competition make an event biased? If I have a set of n numbers, and randomly select numbers without replacement until I have selected n-1 numbers, then told a newcomer he could have the last number, is he still getting a random number? Of course, because entirely random events led to the final outcome. If we started over the result would almost assuredly be different. We would still have one animal that was taller than the rest, but would it be a single outlier like the giraffe? Would it have knobs on its head and spots? Likely not, all because the final outcome began with random events, it is simply a question of which species would mutate first.
Let us also consider the subset of non-fatal, non-advantageous mutations. For if there is nothing in the mutation that effects breeding, then the only question one need to ask is whether or not these individuals lack an advantageous mutation that would eventually cause their distinction. I have attached earlobes and I see many people with detached earlobes. This random mutation seems to have no bearing on the ability to reproduce, and therefore the random mutation that caused it has led to a random outcome with no bias.
Finally, to add one more thing, you seem to make the presumption that sexual selection is entirely choice, and not arbitrary. I don’t know about you, but I don’t tend to bother to check if my partner has hair on their middle phalanges. There is no sexual bias for many of these mutation. Since the mutation is clearly random, and there is clearly no bias that would effect the reproduction of those with hair on their middle phalanges, the outcome is every bit as random as the mutation, for now into eternity.
As for BetaBerry, even though she is incredibly beautiful, my little head is forever reserved for my wife. I don’t really care if marriage is between a man and a woman, two men or two women; I do care about the fidelity and commitment part though. A meeting of the minds - sorry you can’t partake - is what we’ll keep enjoying.
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Wow, hold on, exact same view here friend. I was just playing around because I’m obsessed with pandas.
[quote]tedro wrote:
Mattlebee wrote:
It’s not evolution if it’s arbitrary. It’s also not a random process if the cutoff number has been CHOSEN. Some sexual selection can appear to be arbitrary in its origins, but ultimately there is choice involved.
Survival is what matters and since the majority of random mutations in genes will produce deficient proteins, the majority of mutations will cause the death of the organism (often before birth). The set of random mutations therefore strongly overlaps the set of fatal mutations, but only slightly overlaps the set of advantageous mutations. It is therefore a biased, not random, process.
The problem here is that your set is not collectively exhaustive.[/quote]
It doesn’t reallly need to be. I was only indicating there is a bias and if there’s a bias it’s not random. Whether there are three sets or ten, random chance would populate them all equally. Mutations may be random in their appearance, but not in their consequence.
Disadvantageous mutations don’t have to be directly fatal to cause their owner’s premature death. Any inefficiency in a competitive environment where food is scarce or predators numerous will ultimately cause those genes to be removed more often than the normal form.
Individuals can’t show evolution though. They’re either genetically identical to others in their species or have a mutation. You can only say evolution has occured if that individual reproduces with greater success than the norm, leading to an increase in the number of organisms with the mutation. It’s a very fuzzy area when that sub-population becomes significant enough to be called a sub-species/breed/strain, but you need a stable population to be able to look back and say it evolved from an existing population.
We don’t need to know. If individuals with it consistently increase in number in the population, and the only difference between them and others is the mutated gene, then it is advantageous.
Of course, when the loser(s) of the competition die(s) and the winner propagates themselves.
Because that’s the biggest driver for survival in this situation. Any small height advantage is immediately rewarded with more food, so it becomes a positive feedback until physiological limitations become a problem.
That would depend entirely on how effective the knobs and spots were in other aspects of survival in the situation where all animals were getting taller.
There are always going to be incidental “hanger-on” features because variation applies to all the genes not just the ones being tested for survival advantage. If a poison-resistant rat happened to have crinkly whiskers then, where food is poisoned, all the rats would end up with crinkly whiskers. Crinkly whiskers had nothing to do with the selection process, but nevertheless became the norm through association with poison-resistance.
It can be entirely arbitrary to begin with, but if a feature makes a male more attractive to females then he will have more offspring. If his male offspring inherit this attractive feature they will also be more successful with the ladies and will all have lots of offspring - and so on, with the number of individuals with that feature increasing dramatically over a few generations. The females are choosing males to mate with, but they are also indirectly choosing his genes. If most females in the population like the feature, or if only the most fertile like the feature, it will be guaranteed to spread.
True, but on a level playing field where survival alone isn’t enough to make you stand out as a good mate choice, something else will. If that “something else” is also related to health, lack of parasites or some other desirable trait (as sexual ornaments often are) then what was an arbitrary selection will become a fitness selection as well. No conscious decision-making involved - it will just work.
[quote] Since the mutation is clearly random, and there is clearly no bias that would effect the reproduction of those with hair on their middle phalanges, the outcome is every bit as random as the mutation, for now into eternity.
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Things are different in the human animal as you can override impulses and make more strategic decisions about who you mate with. In animals they simply have a preference for some feature (or combination of features) and chose the best possessor of that feature they can find to breed with.
Also although you say there is “clearly no bias that would effect the reproduction of those with hair on their middle phalanges” - that’s only true by chance. Change it to “hair on the upper lip” and you’ll quickly find men do have a strong preference.
This preference may be arbitrary, or it may have been selected for if the moustache is due to high testosterone/low oestrogen and such women are less fertile. In the distant past any man who found her moustache attractive (or neutral) and picked her as his mate would have fewer offspring. In contrast, the men who had genes that made moustached women unappealing to them, would be chosing more fertile women as mates and therefore propagating the moustache hating genes.
As for BetaBerry, even though she is incredibly beautiful, my little head is forever reserved for my wife. I don’t really care if marriage is between a man and a woman, two men or two women; I do care about the fidelity and commitment part though. A meeting of the minds - sorry you can’t partake - is what we’ll keep enjoying.
Wow, hold on, exact same view here friend. I was just playing around because I’m obsessed with pandas.
[quote]Mattlebee wrote:
It doesn’t reallly need to be. I was only indicating there is a bias and if there’s a bias it’s not random. Whether there are three sets or ten, random chance would populate them all equally. Mutations may be random in their appearance, but not in their consequence.
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Of course it needs to be exhaustive. It is easy to show that nature biasedly favors non-fatal mutations. It is self-evident. However, that does not mean that a subset of a set of all mutations within a population expresses themselves randomly.
Like extra bright, shiny feathers? That is an extremely disadvantageous mutation where predators are numerous, yet one that has seemed to thrive despite no known competitive advantage for survival.
We do indeed need to know. If the bias itself came about randomly, then the result is still random.
Let me get this straight. You accept then that crinkly whiskers came about because of a random mutation, and further acknowledge that they had nothing to do with the selection process, yet you reject that the preponderance of crinkly whiskers is a random occurence? Explainable, yes, but it is still random. Curly whiskers may have had just as much a probability as occuring along side the poison-resistance as the crinkly whiskers.
And again, if you go back to the step where the food became poisoned and found it to be non-toxic but undigestible, the rat that had the mutation to digest the once undigestable food will now pass on his genome most often. The burden is then to show that the food wasn’t randomly poisoned.
Unless of course this feature (mutation) proves fatal before the male can reproduce.
The only thing relevant about this is what makes the feature desireable to the females. Is it a random desire?
Why would humans be different? We all evolved by the same mechanisms, correct? If you exclude humans from a debate on the randomness of evolution then you yourself are introducing bias.
Isn’t that the point?
I disagree. Survival of the fittest (or is it prettiest?) doesn’t tend to affect the females of most species. The preference for hairless upper lips is not near enough to prevent a male from mating with a female. If this is indeed caused by high testosterone, and is an inheritable trait, we can assume that the first generation progeny also have high testosterone. While the number of offspring in the first generation may be lower than average, they will quickly increase. Generation 1 females will be in the same situation as their mother and their respective female offspring. Generation 1 males will also have higher testosterone, which is a desirable trait to the ultimate chooser of natural selection, the female. High testosterone has now-become a non-fatal, advantageous trait.
[quote]Mattlebee wrote:
Aragorn wrote: Mattlebee wrote:
The four building blocks of DNA (or RNA) aren’t especially complex and are just variations on a theme anyway. A single strand of DNA will spontaneously form a double-helix with another (complementary) piece of DNA (or RNA) thereby becoming more stable. Stability is a requirement for continued existence. I think someone else posted a link to an experiment where scientists had made some of the building blocks through simple spontaneous chemical processes.
I have to ask whether you hold a degree in a biochemistry
Yes I do.
because you have attempted to solve in 4-5 sentences something that baffles PhD’s regarding the origin of life.
I wasn’t talking about the origin of life per se, just pointing out that in a situation where you have a mixture of molecules, those that are more stable and those that are able to be replicated will increase their presence. DNA’s greater stability than RNA is why it is the storage molecule for our genes and this comes simply from its molecular properties. Likewise, DNA (and RNA) will fold and base-pair to form stable structures all by itself, so there need be no guiding hand.
The stability of DNA is a major issue in primordial earth, and furthermore the chemical reactions leading to the synthesis of a chain of amino acids is extremely prohibitive without a catalyst.
Yes, the fundamental need for enzymes is the big problem and no-one as yet has all the links in the chain worked out. That doesn’t change the principle that molecules that replicate are like animals that reproduce in the sense that they will increase in number relative to non-replicative molecules.
I’m not going to touch the “it’s tot a random process” thing because it’s obvious we are using two different definitions of random process.
There can only be one definition of random, surely (current teen misuse aside).
In my mind everything starts at the DNA level. mutations at this level ARE random and occur in all “directions”,
Not strictly true. Some mutation types are more common than others and parts of the genome are more exposed to mutagens than others so are more likely to be hit. The Y chromosome appears to mutate more slowly than other chromosomes, though this may be simply because mutations there are more likely to be lethal so are instantly removed from the gene pool. On a naked strand of DNA mutations will occur at random positions, but in DNA in a nucleus in a cell, bound to various proteins (and subject to repair) it’s not so random.
Suffice to say that every time one of my professors’ grant proposals gets turned down it generally contains a statement of implausibility on the idea contained inside.
There are others that occur between competing theories in the literature. “It is improbable this can be explained by x in theory Y” or something similar.
Ah, well these are different. I was talking about big statements that seem to anyone to be implausible e.g. “How could something as complex as the eye just spring into existence by random chance.”
Such statements are designed to trumpet the obvious implausibility in order to advance an alternative position. They’re not detailed theories that require discipline-specific knowledge to notice they might be implausible in reality.
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I really don’t disagree with anything you wrote here regarding the science. All very true. I think we are simply having a “disagreement of degrees”, so to speak, along with a slight misunderstanding of what kind of “implausibility” you were talking about. Some kinds of mutations are definitely more prevalent due to environment and mutagen exposure, but they still happen as you know. Of course molecules that replicate will increase in numbers, providing the molecules are not destroyed by environmental conditions. Once again, a disagreement of degrees.
Yep, I’m definitely familiar with Miller landmark experiment way back when, and Sutherlands work, and others. Sutherlands work is remarkable, and I’m looking for the whole paper since I have very recently lost my academic subscription (graduation) to the journal database we have before I could remember to pull the thing off the online archive. I remain much less hopeful than you do however. The statistical probabilities worked out by Yockey and other prominent information theorists and biologists just don’t lie. They can be modified depending on your starting premises of course, and have been over the years, but not even the most optimistic outcomes are enough to encourage me.
As for BetaBerry, even though she is incredibly beautiful, my little head is forever reserved for my wife. I don’t really care if marriage is between a man and a woman, two men or two women; I do care about the fidelity and commitment part though. A meeting of the minds - sorry you can’t partake - is what we’ll keep enjoying.
Wow, hold on, exact same view here friend. I was just playing around because I’m obsessed with pandas.
We don’t need to know. If individuals with it consistently increase in number in the population, and the only difference between them and others is the mutated gene, then it is advantageous.
We do indeed need to know. If the bias itself came about randomly, then the result is still random.
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Here’s the crux I think. This is what I subscribe to and why I was having difficulty with you saying evolution is non-random. There’s a clear bias shown, but the bias is a result of random forces (earth’s changing environment, which animals, save industrialized humans, cannot alter on any meaningful level)
As for BetaBerry, even though she is incredibly beautiful, my little head is forever reserved for my wife. I don’t really care if marriage is between a man and a woman, two men or two women; I do care about the fidelity and commitment part though. A meeting of the minds - sorry you can’t partake - is what we’ll keep enjoying.
Wow, hold on, exact same view here friend. I was just playing around because I’m obsessed with pandas.
Oh he knows. He was talkin’ to cap’n push.[/quote]
Sure was. Sorry BetaBerry if you thought I was addressing you, I was replying to push’s odd fantasies.
As for Pandas, good call. They’re delicious on the barbecue.
…
There is translation, then meaning, then understanding.
Yes.
…
Now when you have worked out the question of Methuseleh, you will have the meaning of The Flood. Give it a try. It is so much more rewarding than calculating the speed of postdeluvian continental drift.
…
There is translation, then meaning, then understanding.
Yes.
…
Now when you have worked out the question of Methuseleh, you will have the meaning of The Flood. Give it a try. It is so much more rewarding than calculating the speed of postdeluvian continental drift.
What is it you are looking for out of Meth?
…
OK. I will offer a hint:
187+182+600 = 969.
This is better than sudoku!
I honestly couldn’t remember what you were looking for out of me in regards to good ol’ Meth. I knew his age at time of death. Was that all you needed?[/quote]
…
There is translation, then meaning, then understanding.
Yes.
…
Now when you have worked out the question of Methuseleh, you will have the meaning of The Flood. Give it a try. It is so much more rewarding than calculating the speed of postdeluvian continental drift.
What is it you are looking for out of Meth?
…
OK. I will offer a hint:
187 + 182 + 600 = 969.
This is better than sudoku!
I honestly couldn’t remember what you were looking for out of me in regards to good ol’ Meth. I knew his age at time of death. Was that all you needed?
…
There is translation, then meaning, then understanding.
Yes.
…
Now when you have worked out the question of Methuseleh, you will have the meaning of The Flood. Give it a try. It is so much more rewarding than calculating the speed of postdeluvian continental drift.
What is it you are looking for out of Meth?
…
OK. I will offer a hint:
187 + 182 + 600 = 969.
This is better than sudoku!
I honestly couldn’t remember what you were looking for out of me in regards to good ol’ Meth. I knew his age at time of death. Was that all you needed?
Nope. Guess again!
Is 167 + 188 + 600 involved?
[/quote]
Gee, I don’t think so, but I bet I am about to be educated!