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Author Topic:   Mutation
mark24
Member (Idle past 5195 days)
Posts: 3857
From: UK
Joined: 12-01-2001


Message 16 of 171 (97833)
04-05-2004 10:07 AM
Reply to: Message 1 by Muhd
04-05-2004 1:16 AM


Muhd,
Flavobacterial nylon digestion, where a single thymine deletion allowed the metabolism of nylon.
Also, Barry Hall (Hall, 1982) effectively knocked out the lac operon in E.coli, only to see a new enzyme, expression control mechanism, & a new transport molecule that facilitates the movement of lactose into the cell evolve. So, not only have beneficial mutations been observed, but the evolution of complex systems too.
Mark

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RRoman
Inactive Member


Message 17 of 171 (97864)
04-05-2004 12:12 PM
Reply to: Message 1 by Muhd
04-05-2004 1:16 AM


- antibiotic resistance in bacteria
- new strains of the flu
- Multiple new strains of HIV in a person. In fact, the variation among strains of HIV within a single person exceeds the variation of the flu over several years by several order of magnitude!
- pesticide resitance in insects
- fungicide resistance in weeds
- Human bones becoming stronger (High Bone Density Due to a Mutation in LDL-Receptor—Related Protein 5 | NEJM)
- Adaptation to High and Low Temperatures by E. coli.
quote:
A single clone of E. coli was cultured at 37 C (that is 37 degrees Celsius) for 2000 generations. A single clone was then extracted from this population and divided into replicates that were then cultured at either 32 C , 37 C, or 42 C for a total of another 2000 generations. Adaptation of the new lines was periodically measured by competing these selection lines against the ancestor population. By the end of the experiment, the lines cultured at 32 C were shown to be 10% fitter that the ancestor population (at 32 C), and the line cultured at 42 C was shown to be 20% more fit than the ancestor population. The replicate line that was cultured at 37 C showed little improvement over the ancestral line.
Bennett, A.F., Lenski, R.E., & Mittler, J.E. (1992). Evolutionary adaptation to temperature I. Fitness responses of Escherichia coli to changes in its thermal environment. Evolution, 46:16-30.
And my personal favorite, the story of Chlorella Vulagris
quote:
Predation was a powerful selective force promoting increased morphological complexity in a unicellular prey held in constant environmental conditions. The green alga, Chlorella vulgaris, is a well-studied eukaryote, which has retained its normal unicellular form in cultures in our laboratories for thousands of generations. For the experiments reported here, steady-state unicellular C. vulgaris continuous cultures were inoculated with the predator Ochromonas vallescia, a phagotrophic flagellated protist ("flagellate"). Within less than 100 generations of the prey, a multicellular Chlorella growth form became dominant in the culture (subsequently repeated in other cultures). The prey Chlorella first formed globose clusters of tens to hundreds of cells. After about 10-20 generations in the presence of the phagotroph, eight-celled colonies predominated. These colonies retained the eight-celled form indefinitely in continuous culture and when plated onto agar. These self-replicating, stable colonies were virtually immune to predation by the flagellate, but small enough that each Chlorella cell was exposed directly to the nutrient medium. --Changes
quote:
this mutation provided Chlorella with resistance to predation at the cost of growth rate. Neonatal colonies are barely small enough for Ochromonas to engulf. After they have grown slightly they are to big to be eaten. In the presence of the predator, the colonial form of Chlorella displaces the unicellular form and persists. When the predator is not present, the unicellular form displaces the colonial form. This makes sense as the colonial form has less surface area exposed to the environment available for nutrient uptake than the unicellular form has.
quote:
Coloniality in Chlorella vulgaris
Boraas (1983) reported the induction of multicellularity in a strain of Chlorella pyrenoidosa (since reclassified as C. vulgaris) by predation. He was growing the unicellular green alga in the first stage of a two stage continuous culture system as for food for a flagellate predator, Ochromonas sp., that was growing in the second stage. Due to the failure of a pump, flagellates washed back into the first stage. Within five days a colonial form of the Chlorella appeared. It rapidly came to dominate the culture. The colony size ranged from 4 cells to 32 cells. Eventually it stabilized at 8 cells. This colonial form has persisted in culture for about a decade. The new form has been keyed out using a number of algal taxonomic keys. They key out now as being in the genus Coelosphaerium, which is in a different family from Chlorella. "
Boraas, M. E. 1983. Predator induced evolution in chemostat culture. EOS. Transactions of the American Geophysical Union. 64:1102
And I found all this within 10 minutes of surfing the net, and remembering some of my high school biology classes. It astounds me that someone can reject one of the most well supported theories of the last hundred years without doing even 20 minutes of research, or educating oneself about the subject. Here is a nice quote which you would do well to remember:
quote:
Often a non-Christian knows something about the earth, the heavens, and the other parts of the world, about the motions and orbits of the stars and even their sizes and distances,... and this knowledge he holds with certainty from reason and experience. It is thus offensive and disgraceful for an unbeliever to hear a Christian talk nonsense about such things, claiming that what he is saying is based in Scripture. We should do all that we can to avoid such an embarrassing situation, which people see as ignorance in the Christian and laugh to scorn.
--St. Augustine

"Knowledge is Power" - Francis Bacon

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coffee_addict
Member (Idle past 477 days)
Posts: 3645
From: Indianapolis, IN
Joined: 03-29-2004


Message 18 of 171 (97900)
04-05-2004 2:12 PM
Reply to: Message 1 by Muhd
04-05-2004 1:16 AM


This is beginning to look like a hit and run.

This message is a reply to:
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Replies to this message:
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SRO2 
Inactive Member


Message 19 of 171 (97907)
04-05-2004 2:32 PM
Reply to: Message 18 by coffee_addict
04-05-2004 2:12 PM


Hit nad runs
I call them "drive by postings".

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RRoman
Inactive Member


Message 20 of 171 (97934)
04-05-2004 3:59 PM


great, my entire post for nothing.

Replies to this message:
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mark24
Member (Idle past 5195 days)
Posts: 3857
From: UK
Joined: 12-01-2001


Message 21 of 171 (97946)
04-05-2004 4:43 PM
Reply to: Message 20 by RRoman
04-05-2004 3:59 PM


RRoman,
Not for nothing, I enjoyed it.
Mark

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crashfrog
Member (Idle past 1467 days)
Posts: 19762
From: Silver Spring, MD
Joined: 03-20-2003


Message 22 of 171 (97954)
04-05-2004 5:51 PM
Reply to: Message 15 by RAZD
04-05-2004 9:52 AM


let him speak for himself instead of second guessing eh?
If he doesn't know what genetic dominance refers to, he's not going to understand how you misunderstood him. I was just trying to facilitate understanding on both sides.
My point was that the phrase as written was not what a biologist would say.
I think it's safe to say that sometimes we have to make allowances for people who may not be familiar enough with the sciences to get the terms right.
and it doesn't have to become the most common in a population either, it can remain in a varietal subset of the population that eventually accumulates with other changes to cause a speciation separation from the general population.
At which point it's the defining feature of that population, which is what he was saying.
Look, the guy's a crank, I'm sure, but misrepresenting what he was saying doesn't serve anybody.

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Garf
Inactive Member


Message 23 of 171 (97970)
04-05-2004 7:15 PM
Reply to: Message 20 by RRoman
04-05-2004 3:59 PM


great, my entire post for nothing
I liked it, and did learn something, so thanks.

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DC85
Member (Idle past 379 days)
Posts: 876
From: Richmond, Virginia USA
Joined: 05-06-2003


Message 24 of 171 (98002)
04-05-2004 11:55 PM


I do hate hit and run postings.... book mark this topic... Believe this annoying topic will come up again and again and again and again and again and again and again and again and again and again and again and again and again and again.... was I repeating myself?

Replies to this message:
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coffee_addict
Member (Idle past 477 days)
Posts: 3645
From: Indianapolis, IN
Joined: 03-29-2004


Message 25 of 171 (98156)
04-06-2004 4:28 PM
Reply to: Message 24 by DC85
04-05-2004 11:55 PM


What I find hit and run posters so annoying is that they are bound come back some time later and post the exact same rediculous argument all over again and we have to launch our nuclear strike against them again. Since they are immune to new information, they will come back again and again.

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Replies to this message:
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Brad McFall
Member (Idle past 5032 days)
Posts: 3428
From: Ithaca,NY, USA
Joined: 12-20-2001


Message 26 of 171 (98157)
04-06-2004 4:33 PM
Reply to: Message 25 by coffee_addict
04-06-2004 4:28 PM


What is "dominant" or not remains, but 'bit and hit' can not run if the economy of thought we have not had it engender is kept at the broad phylacteris without the legend "up to date." I guess you dismiss this?

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Servus Dei
Inactive Member


Message 27 of 171 (98222)
04-06-2004 8:35 PM
Reply to: Message 1 by Muhd
04-05-2004 1:16 AM


Mutations in Paper
In perusing the board, I came across just what I was looking for: mutations. I am doing a paper on evolution, and I REALLY don't want to misrepresent it. Already, a few reasons have been stated as for how mutations are important and how they work, and I have a basic idea of all of that. I just had a few questions.
1) Assuming that benefits in mutations are helpful traits that increase the organism's (and its offspring's) chances of survival, what are some obvious practical mutations that caused man to evolve into what he is today? Do we know of any?
2) If mutations and natural selection are not the key ways that evolution occurs, what are?
3) How can examples such as finch beaks be used as proof of helpful mutations when no new species is created? (By this, I suppose I am assuming that the helpful mutations create new species - please correct me if I am wrong).
I will probably have more questions later. Also, please try to describe stuff without a lot of the technical jargon that is sometimes used. When it is used, it becomes really boring and hard to understand. I want to write a paper that helps people to understand the issue, not get confused by it. And thanks for any help.
Finally, this last part is the start of my section on the paper. Please point out any areas that seem to be wrong or something. As I said, I am doing this to understand the subject, and to represent evolutionists as they would want to be represented. If you can help out, great, if not, no problem. Thanks for any feedback.
My Paper:
Mutations and natural selection are the key factors that cause evolution. How do mutations and natural selection work? Mutations alter DNA, for the better or for worse. All organisms that are affected by mutations, if they have offspring, future generations are also affected by this mutation. Most mutations are harmful, but there are some that may, in some way, improve the organisms state of being. That is where natural selection plays its role. Natural selection destroys the weak organisms, while the strong ones survive. In a sense, natural selection is like a computer word processor, except in nature. Mutations spit out random letters into the evaluator, and if the letter is one that is going to be used to help construct the sentence the creator of the processor has programed it to create. Evolutionist claim that nature created this word selection processor. Mutations make a split in the line, and this is where the line in ancestors splits to create two or more new species. If the newly mutated form, such as a finch with a larger beak, can survive better because in hardships, it can reach the food source, and others cannot, then the mutated form lives on, and the old form dies out, via natural selection.
How does nature know which creatures to select? Simply whichever species has the advantage, and can survive against the many threats of nature. The word processor does not have a selector in the sense that it has been preprogrammed to accept only the most robust letters. Only those letters survive the journey. Natural selection is close in relation to the survival of the fittest. If an organism can help out nature, and it can survive nature, it will continue to exist.

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Replies to this message:
 Message 28 by crashfrog, posted 04-06-2004 8:58 PM Servus Dei has replied
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crashfrog
Member (Idle past 1467 days)
Posts: 19762
From: Silver Spring, MD
Joined: 03-20-2003


Message 28 of 171 (98232)
04-06-2004 8:58 PM
Reply to: Message 27 by Servus Dei
04-06-2004 8:35 PM


Do we know of any?
Well-developed throats, large areas of the brain devoted to language, upright posture, thin body hair, large male genitals, etc.
If mutations and natural selection are not the key ways that evolution occurs, what are?
Those are the key ways that evolution occurs, yes. Reproductive isolation is the key way that new species form.
How can examples such as finch beaks be used as proof of helpful mutations when no new species is created? (By this, I suppose I am assuming that the helpful mutations create new species - please correct me if I am wrong).
Yeah, you're slightly wrong.
Mutations don't create new species by themselves. It has to be mutation occuring in a situation of reproductive isolation. An isolated subpopulation accumulates mutations that aren't shared with the main population until the subpopulation is no longer able to breed with the main population.
At that point you have a new species. When did it happen? Well, that's about as hard to answer as "when did it start raining?" Speciation is the result of a process, not an event in itself.
Most mutations are harmful
This is wrong. Most mutations have no effect on the organism.
but there are some that may, in some way, improve the organisms state of being.
You might want to keep in mind that it's only the environment that determines whether or not a mutation is harmful, neutral, or beneficial.

This message is a reply to:
 Message 27 by Servus Dei, posted 04-06-2004 8:35 PM Servus Dei has replied

Replies to this message:
 Message 29 by Servus Dei, posted 04-06-2004 10:25 PM crashfrog has replied

  
Servus Dei
Inactive Member


Message 29 of 171 (98256)
04-06-2004 10:25 PM
Reply to: Message 28 by crashfrog
04-06-2004 8:58 PM


Crashfrog: I had a few questions to your response (by the way, thanks for that)
How can one tell that the developed throats and brain are a result of mutations? Also, doesn't that assume right off that evolution is how we came to exist. (i'm not necessarily saying that's wrong, but just wondering) It also seems that it would be hard to tell the timing of these mutations, correct?
Thanks for correcting me on the harmful part of mutations. Isn't it true that mutations are rather rare? How could the evolution of a species occurred if only a few, or a single species got that genetic mutation? Wouldn't the greater population of other (birds for example) make it so that the new mutated form would never get a chance to gain into a majority, unless you have a case of the reproductive isolation that you talked about? Even then, isn't it a bit extreme to say that all evolution happened due to reproductive isolation (maybe you don't say this, but that's what you seemed to imply)?
And please pardon my ignorance, but how is it that the environment determines the outcome of mutations? I just have never heard of that before, and so I am curious.

This message is a reply to:
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Replies to this message:
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 Message 31 by crashfrog, posted 04-06-2004 10:59 PM Servus Dei has replied

  
Coragyps
Member (Idle past 734 days)
Posts: 5553
From: Snyder, Texas, USA
Joined: 11-12-2002


Message 30 of 171 (98264)
04-06-2004 10:49 PM
Reply to: Message 29 by Servus Dei
04-06-2004 10:25 PM


SD, you might want a peek at
Understanding Evolution - Your one-stop source for information on evolution
High-school level stuff, and I'm sure there is plenty there on the role of mutations.

This message is a reply to:
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