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Author | Topic: The Dawkins question, new "information" in the genome? | |||||||||||||||||||||||
creationistal Inactive Member |
I'm sure many of you have heard of the question for Richard Dawkins asking for an example or evolutionary process adding new genetic information. There was a small broohaha over it, but I am still unclear on answers to the question, though poorly asked IMHO. I have a similar question/thought.
Given that life started sometime, in its simplest form, at some point, new information must be added for it to "evolve", that is, get from there to where we are today. A single-celled organism is a far cry from a fish, or a dog, etc. How does a single-celled organism become a two-celled organism? I am very unclear on exactly how evolution explains this. Maybe I'm just uneducated on the subject (which I am, I think), but I feel like I'm searching for a needle in a haystack here. How does this process work? Do we have examples of it? -Justin (Topic move efforts have had technical problems. Will now try to spin this message 1 off as the new topic. - Adminnemooseus}
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crashfrog Member (Idle past 1467 days) Posts: 19762 From: Silver Spring, MD Joined: |
I'm sure many of you have heard of the question for Richard Dawkins asking for an example or evolutionary process adding new genetic information. There's a bazillion examples of this, some of which Dawkins supplied; that portion of his response was cut from the interview in which he appears. But the process that addes novel genetic sequences to genomes is random mutation. The process that causes those sequences to come to dominate the genome, or to be extinguished from it, is natural selection.
Given that life started sometime, in its simplest form, at some point, new information must be added for it to "evolve", that is, get from there to where we are today. Why? I will grant you that metazoan life requires additional genetic sequences that a simpler form of life would not have; does that neccessitate additional genetic information? Since I don't know what "information" is supposed to be, you tell me.
A single-celled organism is a far cry from a fish, or a dog, etc. Obviously, and that must be due to genetics, but it's a considerable leap to propose that that difference is due to the "amount" of some kind of hypothetical "genetic information." Usually, there's almost no correlation between the complexity of an organism and the length of its genome.
How does a single-celled organism become a two-celled organism? Generally, as an adaptation against predation, like in this example of colonality arising in a blue-green algae:
quote: (Emphasis added by me.) That's my favorite example, because it shows how multicelluarity can arise spontaneously as an adaptation to predation. The next step from colonality is specialization of cells; there's a great deal of transitional steps that survive in the invertebrate kingdom. For instance, sponges have only three types of cells.
How does this process work? Random mutation and natural selection. The selection pressure is predatory.
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Zhimbo Member (Idle past 6012 days) Posts: 571 From: New Hampshire, USA Joined: |
What you need to ask yourself is...what is information? How do you know when "more" or "less" information is present? This can get pretty technical, but for now let's keep it intuitive, and see where that gets us.
I don't think any creationist denies that a gene can be duplicated. Nor do I think any creationist denies that one of these genes can undergo a mutation. Now you have two genes, one different from the other. By any reasonable definition I know for the word "information", the example I presented is an example of increased information through natural mechanisms.
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creationistal Inactive Member |
Okay I think I get it, for the most part. Except for this "information" thing.
Say that a one-celled organism is sitting here. It is complete, it is all. Now something happens. Suddenly a mutation that happens to not kill it off or do nothing instead lets it have the "information" needed to become something else, two-celled for instance. It seems to me that evolution is sort of like playing yahtzee for a billion years and rolling all good numbers the entire time, blindly and with no purpose. I don't get it. I must be missing something here. -Justin
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Dr Jack Member Posts: 3514 From: Immigrant in the land of Deutsch Joined: Member Rating: 8.7 |
Say that a one-celled organism is sitting here. It is complete, it is all. Now something happens. Suddenly a mutation that happens to not kill it off or do nothing instead lets it have the "information" needed to become something else, two-celled for instance. No-one has yet presented a decent definition for what "information" is, or what a change in it means so let's put the whole concept aside and look at the facts that we know. When a single-celled organism reproduces it does so by doubling it's genetic material and then splitting into two halves (loosely speaking - they're not always equal in size) each containing a full set of genes. Trouble is the copying process by which genes are doubled is not perfect so there are errors in the copy. We call these errors "mutations". Most mutations have little or no effect, some are "harmful" and reduce the ability of that single celled organism to survive and reproduce in it's environment others are "beneficial" and increase that organisms ability to survive and reproduce. (I've put "harmful" and "beneficial" in quotes, because they're very much value judgements rather than absolute qualities - what is harmful in one circumstance may be beneficial in another, and most changes in fact involve a mixture of pros or cons) Now, it doesn't take a genius to figure out that an organism that is better at surviving and reproducing is going to have more descendents that one that is worse at it. This is Natural Selection. Chances are the shift from single-celled to communal organisms was made because of a change in the environment. Just as in the example posted above.
It seems to me that evolution is sort of like playing yahtzee for a billion years and rolling all good numbers the entire time, blindly and with no purpose. No. It's not. Mutation is random, and produces a mixture of good and bad rolls. Natural Selection weeds out the bad rolls and keeps the good and, thus, over time will optimise an organism with the best genes for living in the environment it is found in.
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creationistal Inactive Member |
Mutation is random, and produces a mixture of good and bad rolls. Natural Selection weeds out the bad rolls and keeps the good and Yeah, and like you said, most of them don't do anything. Even the most simple lifeform is more complex than any machine we have ever conceived of, and you are telling me that time + luck = the human brain. Time + luck = love, or respect, or pride. I can't buy that. There's gotta be something mroe to it. -Justin
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creationistal Inactive Member |
Mutation is random, and produces a mixture of good and bad rolls. Natural Selection weeds out the bad rolls and keeps the good and Yeah, and like you said, most of them don't do anything. Even the most simple lifeform is more complex than any machine we have ever conceived of, and you are telling me that time + luck = the human brain. Time + luck = love, or respect, or pride. I can't buy that. There's gotta be something more to it. -Justin
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Dr Jack Member Posts: 3514 From: Immigrant in the land of Deutsch Joined: Member Rating: 8.7 |
No, I'm not telling you that time + luck produces these things, I'm telling you that Natural Selection combined with Mutation produces these things.
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Chiroptera Inactive Member |
Yes, there is more to it: natural selection.
If you were to roll 10 dice, how long would it take you to get 10 6's? You would have to roll them about 60 million times before you can expect to get 10 6's. Now roll those 10 dice. Select the ones that come up 6, set them aside, and reroll the rest. Of those, select the ones that come up 6, place them with the other 6's, and reroll the rest. Continue. You will find that in short order you can get 10 6's, much much quicker than relying on pure chance. Now this analogy is not really how evolution works (the most important difference is that I specified the outcome in advance). But the point is that a very unlikely outcome (10 6's) can be produced by a random process (dice rolling) if there is a selection process. In the case of evolution, you have a random process that produces novel variations (genetic mutations), but there is a selection process, namely those less able to survive end up dying, that very quickly drives the evolution of what seems to be fascinatingly complex structures and behaviours.
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creationistal Inactive Member |
Okay. So give me an example of how natural selection can create a need for something like an eye, or skin, or anything complex that serves a function, when those things do not yet exist.
-Justin
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jar Member (Idle past 394 days) Posts: 34026 From: Texas!! Joined: |
Okay. So give me an example of how natural selection can create a need for something like an eye, or skin, or anything complex that serves a function, when those things do not yet exist. Actually, you have the order wrong. Evolution is not directed, does not have a goal. Natural seclection does not create a need. What happens is random changes. Let's use vision as an example. Some critter is born with a mutation that let's it sense lighter or darker areas. For example, it may be able to sense shadows and so can tell when it's close to prey. It has a better change for finding food than the other similar critters that can only stumble on dinner. So it has a better chance of eating well and living long enough to reproduce and pass on that mutation. The change was random. Natural selection filtered out those without the mutation. Aslan is not a Tame Lion
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creationistal Inactive Member |
Before you get too defensive, let it be known that I am conceding that there is much evidence that supports the theory of evolution. What I am getting at is that given what we know now, and more importantly, what we *don't* know (WHICH IS A TREMENDOUS AMOUNT), I do not think *anyone* can definitively say how we got to where we are with certainty.
There remains to be done *much* discovering of fossils before anything is certain, at the very least. -Justin
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creationistal Inactive Member |
So give me an example of a mutation giving something the ability to sense light and dark?
-Justin
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crashfrog Member (Idle past 1467 days) Posts: 19762 From: Silver Spring, MD Joined: |
I do not think *anyone* can definitively say how we got to where we are with certainty. I don't think anyone has. The conclusions of science, and evolution is such a conclusion, are always tentative. We say "we are confident this is the most accurate model at this time, but we're ready to revise it in the light of new data."
There remains to be done *much* discovering of fossils before anything is certain, at the very least. No amount of fossils will make the theory more "certain", because that's not how it works. The theory of evolution, like the germ theory of disease or the theory of gravity, will always stay tentative. But each new fossil we find - and we have a lot of fossils - lends further support to the theory of evolution.
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creationistal Inactive Member |
I mentioned fossils because there is nothing in the record right now showing even the beginnings of transitions. Things appear to be now, aside from adaptations to environment and small mutational changes, to be exactly as they were when they appeared.
-Justin
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