Evolution: the source of information?

[LetThereBe]

One question: where does new genetic information for the evolutionary process come from? I understand that mutations can result in different traits, but that is not actually a generation of new DNA. I'm sure no one would argue that the first single-celled life form had all of the genetic material necessary to form birds, reptiles, fish, humans, etc.
So, how does the information carried in the cell of a life form actually increase? Its one thing to see changes because of a loss or rearrangement of DNA, but an increase?

I have heard that polyploidy doubles the same information, and I suppose that could conceivably then be mutated, though I'm not sure how much mutation would be necessary to make an exact duplicate DNA code create different traits. That seems to be an unlikely answer regardless, as it is very rare except in some varieties in plants.

[SteveA]

Children inherit traits from the parents, as well as mutations. The inherited traits come from either parent randomly but the mutations are original and a source of new genetic information.

This doesn't explain how DNA sequences have grown in length over time though to create entirely new species though, unless they are due to mutations that affect a large part of the DNA.

[Starboy]

http://www.talkorigins.org/origins/postmonth/jan99.html

Starboy

[LetThereBe]

Quote by: SteveA Children inherit traits from the parents, as well as mutations. The inherited traits come from either parent randomly but the mutations are original and a source of new genetic information. This doesn't explain how DNA sequences have grown in length over time though to create entirely new species though, unless they are due to mutations that affect a large part of the DNA.

That is what I was trying to refer to, the increase in length of the DNA sequences. Thank you for clarifying my question.

[LetThereBe]

Quote by: Starboy http://www.talkorigins.org/origins/postmonth/jan99.html Starboy

Interesting article. However, it acknowledges that polyploidy is common in plants, found in some animals, but not all. Obviously chromosome fusion can't account for an increase in the DNA sequence length, and it says chromosome fission is unlikely to have increased the sequence. It seems (even according to that article) that polyploidy is an insufficient explanation.

[gallo]

Polyploidy is relatively common in plants. Generally, the new plant with double the chromosome numbers is not interfertile with the original species. Thus, a new species can be born in a single generation.

There are also cases where two related species have formed a hybrid that was not interfertile with either parent. Again, this is a new species in a single generation. I believe that wheat is an example of this.

The case in which a segment of a chromosome is doubled during reproduction has also been recorded, sometimes on the same chromosome and sometimes transposed to a different chrosome. In that case, even if the original function of the protein coded in the gene is essential, the second copy is free to mutate.

For example, hemoglobin is made up of two proteins (alpha, beta) and a third that is active in a fetus instead of beta (gamma). Four genes code for the alpha protein, two for the beta protein, and 2 for the gamma protein. These multiple copies of genes probably arose by duplication. Mutations in these genes have caused things like blood types, Rh factors and other differences in the blood. There are hundreds of variant hemoglobins, most of which function normally. They provide genetic diversity in the face of environmental challenges. For example, one of the blood types gives greater resistance to bubonic plague and one of the variant hemoglobins gives resistance to malaria.

The hox gene are controlling genes that control the expression of other genes. There are four hox gene clusters (A, B, C, D) in vertebrates that are organized into 13 homology groups. Other organisms may have fewer holology groups and/or fewer gene clusters. But all organisms have hox genes that have similar functions. They are so similar that replacing a hox gene from a different animal (eg. from fly to mouse) doesn't change the function.

However, if you want to talk about "information" in reference to biology, you need to define what you mean. Creationists have relied on the original Shannon definition in which, by definition, information cannot increase in the transmission. That definition isn't really relevant to genetic information.

[LetThereBe]

Quote by: gallo Polyploidy is relatively common in plants. Generally, the new plant with double the chromosome numbers is not interfertile with the original species. Thus, a new species can be born in a single generation. There are also cases where two related species have formed a hybrid that was not interfertile with either parent. Again, this is a new species in a single generation. I believe that wheat is an example of this. The case in which a segment of a chromosome is doubled during reproduction has also been recorded, sometimes on the same chromosome and sometimes transposed to a different chrosome. In that case, even if the original function of the protein coded in the gene is essential, the second copy is free to mutate. For example, hemoglobin is made up of two proteins (alpha, beta) and a third that is active in a fetus instead of beta (gamma). Four genes code for the alpha protein, two for the beta protein, and 2 for the gamma protein. These multiple copies of genes probably arose by duplication. Mutations in these genes have caused things like blood types, Rh factors and other differences in the blood. There are hundreds of variant hemoglobins, most of which function normally. They provide genetic diversity in the face of environmental challenges. For example, one of the blood types gives greater resistance to bubonic plague and one of the variant hemoglobins gives resistance to malaria. The hox gene are controlling genes that control the expression of other genes. There are four hox gene clusters (A, B, C, D) in vertebrates that are organized into 13 homology groups. Other organisms may have fewer holology groups and/or fewer gene clusters. But all organisms have hox genes that have similar functions. They are so similar that replacing a hox gene from a different animal (eg. from fly to mouse) doesn't change the function. However, if you want to talk about "information" in reference to biology, you need to define what you mean. Creationists have relied on the original Shannon definition in which, by definition, information cannot increase in the transmission. That definition isn't really relevant to genetic information.

By increase in information, lets simply put it as "the increase in length of the DNA sequences" Again, I already knew polyploidy was somewhat common in plants, but it is much rarer in many animals, and completely unknown in others. So how could this be a viable explanation? It drastically increases the requirements for evolution to take place.

[white rice]

The latest theory is that our bodies are conglomerations of several foreign bodies, such as bacteria and parasites, that mold particular functions into our systems. It's been postulated that the brain's increased function through adolecences gets help from parasites. (too lazy to Google).

I mean one of the great advances in cell structure, eukaryotes, was made possible by the incorporation of mitochondia's and chloroplast's (in plant or plantlike organisms) ancestrial bacterial cells. Using that idea, you can say that our DNA made a hull (body) for specialized cells to operate inside (such as bacteria living inside our intestines) AND manipulate (such as viruses).

Then there's communities full of singular celled organisms who clump together and perform multicellular tasks through differentiation even though they have mostly the same genetic information within their species.

So the analogy here is you begin with one thinking mind and make him figure out a timed puzzle. You clone that thinking mind (with some defects), and let them do that timed puzzle cooperatively. Sometimes there's competition within clones, but this experiment has millions of teams. The teams that win, move on. Cooperative teams that eventually focus on one certain tasks could become more efficient at solving the puzzle. But it's not always beneficial because the bigger numbers, the more energy is needed. So each cooperative team also needs better management as well as high productivity....meaning after thousands/millions of cloned ancestrial lines, that original clone's (with some defects) legacy (great-great-great grandchildren times a million) is much different than the original cell's legacy. Even though they originally started off from the same blueprint.

Not one of these possibilities are definitive. Epigenesis is hitting new strides such as the mice study of you are what your mother eats... http://www.newscientist.com/article.ns?id=dn4017

[LetThereBe]

Quote by: white rice The latest theory is that our bodies are conglomerations of several foreign bodies, such as bacteria and parasites, that mold particular functions into our systems. It's been postulated that the brain's increased function through adolecences gets help from parasites. (too lazy to Google). I mean one of the great advances in cell structure, eukaryotes, was made possible by the incorporation of mitochondia's and chloroplast's (in plant or plantlike organisms) ancestrial bacterial cells. Using that idea, you can say that our DNA made a hull (body) for specialized cells to operate inside (such as bacteria living inside our intestines) AND manipulate (such as viruses). Then there's communities full of singular celled organisms who clump together and perform multicellular tasks through differentiation even though they have mostly the same genetic information within their species. So the analogy here is you begin with one thinking mind and make him figure out a timed puzzle. You clone that thinking mind (with some defects), and let them do that timed puzzle cooperatively. Sometimes there's competition within clones, but this experiment has millions of teams. The teams that win, move on. Cooperative teams that eventually focus on one certain tasks could become more efficient at solving the puzzle. But it's not always beneficial because the bigger numbers, the more energy is needed. So each cooperative team also needs better management as well as high productivity....meaning after thousands/millions of cloned ancestrial lines, that original clone's (with some defects) legacy (great-great-great grandchildren times a million) is much different than the original cell's legacy. Even though they originally started off from the same blueprint. Not one of these possibilities are definitive. Epigenesis is hitting new strides such as the mice study of you are what your mother eats... http://www.newscientist.com/article.ns?id=dn4017

All very interesting, but I'm still not sure that could account for an actual increase in the length of the DNA sequence, especially in the higher animals.

[Starboy]

Quote by: LetThereBe Interesting article. However, it acknowledges that polyploidy is common in plants, found in some animals, but not all. Obviously chromosome fusion can't account for an increase in the DNA sequence length, and it says chromosome fission is unlikely to have increased the sequence. It seems (even according to that article) that polyploidy is an insufficient explanation.

Yup, that is the problem with scientific explanations. They are not perfect. They are a work in progress. It was only fifty years ago that the structure of DNA was discovered. There is still much to learn. But the way to find it out is not say "goddidit". That answers nothing.

Starboy

[LetThereBe]

Quote by: Starboy Yup, that is the problem with scientific explanations. They are not perfect. They are a work in progress. It was only fifty years ago that the structure of DNA was discovered. There is still much to learn. But the way to find it out is not say "goddidit". That answers nothing. Starboy

I don't even recall saying the word "God" on this thread. I was merely wondering if there WAS an answer that satisfied my question. Is it wrong to seek information?

[white rice]

Quote by: LetThereBe All very interesting, but I'm still not sure that could account for an actual increase in the length of the DNA sequence, especially in the higher animals.

An example of degradation is the Y male chromosome. It's the only one of it's kind to the 23 human base pairs. Because there's no self repair through redundancy (unlike the X chromosome), it's whittling down as the millenia passes by. It's like the eraser at the end of the pencil after every use.

Most times polyploidy is a genetic defect among mammals. Other defects, such as transcription errors will prevent gene replicators (tRNA) from stopping replication and therefore lengthening the chromosome. Cancer itself is the result of mutations gone wrong (although somatic). Genetic mutations happen in many ways and most of the negative ones terminate early after conception or birth.

Over time, if that redundancy gives the specimen a positive or neutral trait to it's environment, that'll give it room for future generations to mutate.

Keep in mind that life on earth has rumored to come as early as 3 billion years ago and this isn't counting the possibility of xenogenesis (from asteroids/aliens/outerspace...) from a more ancient cell strain. Comparatively, the current human species is no more than 2 million years old and recorded civilization is around 10,000.

I hope this satisfies your initial curiosity to research more on the matter.

[Starboy]

Quote by: LetThereBe I don't even recall saying the word "God" on this thread. I was merely wondering if there WAS an answer that satisfied my question. Is it wrong to seek information?

Not at all. And as long as you do not jump to conclusions because of ignorance then I see nothing wrong.

Starboy

[gallo]

Quote by: LetThereBe By increase in information, lets simply put it as "the increase in length of the DNA sequences" Again, I already knew polyploidy was somewhat common in plants, but it is much rarer in many animals, and completely unknown in others. So how could this be a viable explanation? It drastically increases the requirements for evolution to take place.

But no one claims that polyploidy is the only method for an increase in DNA length. I guess you weren't paying attention to the discussion since I mentioned other methods.

Perhaps you would do better to state your "theory" on the matter and offer evidence to support that theory (hypothesis, prediction, and experimental testing).

We know that information can increase in the genome of any organism. We have seen it happen. In fact, any mutation that is not lethal results in an increase in information in a given genome.

I asked that you define information in a biological context. You seem to pretend that you didn't see the question. I think that you can't actually define information.

[Athena]

Quote by: LetThereBe One question: where does new genetic information for the evolutionary process come from? I understand that mutations can result in different traits, but that is not actually a generation of new DNA. I'm sure no one would argue that the first single-celled life form had all of the genetic material necessary to form birds, reptiles, fish, humans, etc. So, how does the information carried in the cell of a life form actually increase? Its one thing to see changes because of a loss or rearrangement of DNA, but an increase? I have heard that polyploidy doubles the same information, and I suppose that could conceivably then be mutated, though I'm not sure how much mutation would be necessary to make an exact duplicate DNA code create different traits. That seems to be an unlikely answer regardless, as it is very rare except in some varieties in plants.

I suggest you read "The lives of a Cell" by Lewis Thomas. It is a very amusing and easy book to read.

"We carry stores of DNA in our nuclei that may have come in, at one time or another, from the fusion of ancestral cells and the linking of ancestral organisms in symbiosis. Our genones are catalogues of instructions from all kinds of sources in nature, filed for all kinds of contingencies. As for me, I am grateful for differentiation and spectation, but I can not feel as separate an entity as I did a few years ago, before I was told these things, nor, I should think, can anyone else."

The earliest living organisms formed societies and occasional they formed not only symbiotic relationships, but one would begin living inside another. We would die if it were not for other other organisms living inside us helping us digest food. Or we can die if the wrong organism enters our bobies. This is sad for the viruses that cause death, because when the body they occupy deads, so do they.

So the bird virus that is now threatened an epidmic is looking for a human host who will not die so fast. When the host days within hours, or only a few days, this is not enough time for the virus to reproduce and spread to another host body. A really good host body like Typhoid Mary, doesn't even get sick, but just carries the disease. But now I diverge too far from the subject.

Better education would do wonders for our populations don't you think?

[LetThereBe]

Quote by: gallo But no one claims that polyploidy is the only method for an increase in DNA length. I guess you weren't paying attention to the discussion since I mentioned other methods. Perhaps you would do better to state your "theory" on the matter and offer evidence to support that theory (hypothesis, prediction, and experimental testing). We know that information can increase in the genome of any organism. We have seen it happen. In fact, any mutation that is not lethal results in an increase in information in a given genome. I asked that you define information in a biological context. You seem to pretend that you didn't see the question. I think that you can't actually define information.

First: I don't have a theory on the matter. Why do you take offence when I question what is generally accepted?
Second: Not every mutation is an increase in information. Most of the time it is a change or a removal of information. For example albinoism is not the result of an increase, but in the removal or corruption of the genes that create pigment in the skin.
Third: When I said increase in information I meant "increase in the length of the DNA sequence." A single celled organism might have, I don't know, 500,000 DNA "letters" while a human might have ten billion. That is the increase to which I refer. I apologize for my unclear terms.

[gallo]

Quote by: LetThereBe First: I don't have a theory on the matter. Why do you take offence when I question what is generally accepted?

Why take offense when I ask you to support your assertions? I merely pointed out that I had previously, in the very post to which you responded, dealt with the answers to your objection. Weren't you paying attention? Why insist that polyploidy is the only method by which DNA can increase? If you think that is true, then support your assertion with references.

Quote by: LetThereBe Second: Not every mutation is an increase in information. Most of the time it is a change or a removal of information. For example albinoism is not the result of an increase, but in the removal or corruption of the genes that create pigment in the skin.

I asked you to define information in a biological context. Again you babble on about information without telling us what it is. If you simply mean an increase in the number of base pairs in a genome, then no, a mutation that causes albinism is not an increase in information. But on the other hand, it isn't a decrease either since a simple point mutation doesn't change the number of base pairs in the affected gene. So please, before you continue to pontificate about what is or isn't possible in biology, define what you are talking about.

Quote by: LetThereBe Third: When I said increase in information I meant "increase in the length of the DNA sequence." A single celled organism might have, I don't know, 500,000 DNA "letters" while a human might have ten billion. That is the increase to which I refer. I apologize for my unclear terms.

Then you were babbling. Above you gave an example of a point mutation in a gene that causes albinism and claimed that it was a decrease in information. Now you are claiming that because you don't understand all of the ways in which the amount of DNA in an organism can increase, you don't believe that it is sufficient for evolution.

If all you meant just the number of base pairs in the DNA, why didn't you say that. Why call it informatioin. In communications theory the word information has specific meaning. Creationists love to try to apply that meaning, i.e. Shannon information, to genetics because by that definition information can never increase. However, when applied to other fields the definitions of information have multiplied. I all you meant was the number of base pairs in a strand of DNA, then an increase in information is common place.

Here's a hypothetical for you. Suppose that a species of animal exists in which in the entire population there is no gene that causes albinism. Now suppose that such a mutation takes place at a single base at a single locus in a single egg in a single animal, and that the egg is fertilized and a young animal is born and it lives to adulthood and enters the breeding population. There is now an allele of a particular gene, capable of being passed on, in the genome of that animal that never existed before. Please explain how that is not more information in the genome than previously existed.

[LetThereBe]

Quote by: gallo If all you meant just the number of base pairs in the DNA, why didn't you say that. Why call it informatioin. In communications theory the word information has specific meaning. Creationists love to try to apply that meaning, i.e. Shannon information, to genetics because by that definition information can never increase. However, when applied to other fields the definitions of information have multiplied. I all you meant was the number of base pairs in a strand of DNA, then an increase in information is common place. .

Again, I apologize for my poor terminology. My question should have read then "how do we get more base pairs" A standard mutation will not create more. What other explanation is there other than polyploidy to increase base pairs? It is necessary because most lower level organisms have fewer.

[Starboy]

There are genetic disorders that happen all the time where extra chromosomes are produced.

http://library.thinkquest.org/18258/chromosome.htm

Nondisjunction: two chromosomes of a pair fail to separate during meiosis, resulting in a "pair" with an extra chromosome and a "pair" with only one chromosome. Examples are Down's Syndrome, Klinefelter's Syndrome, and Turner's Syndrome.

Starboy

[LetThereBe]

Quote by: Starboy There are genetic disorders that happen all the time where extra chromosomes are produced. http://library.thinkquest.org/18258/chromosome.htm Starboy

Yes, but are there any known that don't have such an obvious negative impact on the organism?