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Author Topic:   Mutation
crashfrog
Member (Idle past 398 days)
Posts: 19762
From: Silver Spring, MD
Joined: 03-20-2003


Message 31 of 171 (98268)
04-06-2004 10:59 PM
Reply to: Message 29 by Servus Dei
04-06-2004 10:25 PM


How can one tell that the developed throats and brain are a result of mutations?

Because that's the only observed mechanism for the introduction of genetic material into the gene pool of a population.

The alternative is that humans have always had these genes because humans were created with them, but we've never observed a mechanism that can create an organism wholesale from scratch.

Isn't it true that mutations are rather rare?

No, they're quite common. You probably have between 50 and 500 (rough estimate) mutations of your very own. Obviously they're neutral ones, or else you'd notice. Then again there's the occasional human with a noticable mutation, like a lack of wisdom teeth.

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

Sometimes that happens. But a beneficial mutation is one that allows that organism to leave more progeny than it's competitors. Therefore by definition the mutation will become more common because individuals with the mutation are outcompeting and outreproducing the individuals who lack it.

Remember also that it isn't "muties vs. normals." The individuals without the mutation don't band together against the individual with it. They're competing against each other, too.

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)?

All speciation happens as a result of reproductive isolation. Huh, I'm surprised you missed that; I thought I had been pretty clear about it.

Evolution is when allele frequencies change within a gene pool. Speciation separates gene pools permanently (which can change allele frequencies.) Reproductive isolation interrupts gene flow, which allows speciation to occur.

And please pardon my ignorance, but how is it that the environment determines the outcome of mutations?

By selection. Beneficial mutations are mutations that are selected for. Harmful mutations are mutations that are selected against. Of course, it's not like the environment is picking and choosing, any more than the roulette wheel "chooses" where the ball lands. Selection is just the name we give to the observation that organisms adapted to their environment tend to leave more offspring than the ones that don't.

For instance - what if you had a mutation that gave you thick, insulating fur? Is that a beneficial mutation or a harmful one? Kinda depends on whether you live at the North Pole or in Africa, doesn't it?


This message is a reply to:
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Replies to this message:
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DC85
Member (Idle past 113 days)
Posts: 876
From: Richmond, Virginia USA
Joined: 05-06-2003


Message 32 of 171 (98305)
04-07-2004 1:08 AM
Reply to: Message 27 by Servus Dei
04-06-2004 8:35 PM


Re: Mutations in Paper
Most mutations are harmful

This is false every Creature has some kind of Mutation.. so most are Just not Visable and don't effect the creature either way...

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DC85
Member (Idle past 113 days)
Posts: 876
From: Richmond, Virginia USA
Joined: 05-06-2003


Message 33 of 171 (98306)
04-07-2004 1:08 AM
Reply to: Message 27 by Servus Dei
04-06-2004 8:35 PM


Re: Mutations in Paper
Most mutations are harmful

This is false every Creature has some kind of Mutation.. so most are Just not Visable and don't effect the creature either way...

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SweeneyTodd
Inactive Member


Message 34 of 171 (98345)
04-07-2004 4:47 AM
Reply to: Message 3 by Muhd
04-05-2004 1:27 AM


Re: What!?!
Adaptation occurs within one generation where as evolution, even on its smallest scale, only happens through heredity. I've had creationist friends that played word games where evolution didn't happen but "adaptation" did. Where if they really understood the definitions they would realize they didn't know what adaptation meant.

Most mutations are nuetral. Not helping or harming an organism, and this is one of the ways we trace common ancestors...by identifying these nuetral mutations.

As far as beneficial mutations...sickle cell anemia is sort of beneficial if you happen to live in an area where malaria is prevalent.

[This message has been edited by SweeneyTodd, 04-07-2004]


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Wounded King
Member (Idle past 3026 days)
Posts: 4149
From: Edinburgh, Scotland
Joined: 04-09-2003


Message 35 of 171 (98351)
04-07-2004 5:13 AM
Reply to: Message 34 by SweeneyTodd
04-07-2004 4:47 AM


Re: What!?!
Just to be picky, its sickle cell anaemia.

This message is a reply to:
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SweeneyTodd
Inactive Member


Message 36 of 171 (98356)
04-07-2004 5:20 AM
Reply to: Message 35 by Wounded King
04-07-2004 5:13 AM


Picky...
Just to be picky, its sickle cell anemia.

**Sorry...anaemia/anemia...colour/color...

My bad

[This message has been edited by SweeneyTodd, 04-07-2004]


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Denesha
Inactive Member


Message 37 of 171 (98358)
04-07-2004 5:30 AM
Reply to: Message 34 by SweeneyTodd
04-07-2004 4:47 AM


Re: What!?!
Dear Sweeneytodd,

This seems true for a given environment. If changes occurs, the helpful/harmful ratio will have an other signification.

What was helpful to Early Cretaceous dinosaurs was harmful for uppermost Cretaceous dinosaurs. Their is a nice dictum: "Extinctions: bad genes or bad luck" (David Raup)

I think that the beneficial of mutations is allways positive, even if it is very small. Overwise, our days biodiversity should be very low.

Denesha


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Milagros
Inactive Member


Message 38 of 171 (98443)
04-07-2004 2:52 PM


"Most mutations are harmful"

DC85
"This is false every Creature has some kind of Mutation.. so most are Just not Visable and don't effect the creature either way..."
------------------------------------------------------------------------

With all due respect DC85 but what you've said is not entirely true. Here's a Quote by Edward E.Max on the Talk.origins site, he clearly states that,

"While it is true that most mutations are either harmful, as suggested by the creationists, or neutral, the creationists gloss over a crucial fact: beneficial mutations do occur, though they are very rare."

Here's the site so you can confirm it yourself, I don't want to be accused of taking anyone's statement out of context. However I'm only providing this so you won't take "MY" word for it. http://www.talkorigins.org/faqs/fitness/ Specifically under the heading "1.2.1 Are all mutations harmful?"

But notice he does say that MOST ARE "harmful" or "neutral". I'm not talking about any "beneficial" ones, I am ONLY addressing your response where you claim that "This is false...." to the statement made earlier that "Most mutations are harmful".


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Milagros
Inactive Member


Message 39 of 171 (98449)
04-07-2004 3:31 PM


Also DC85 , what do you mean, "most are not Visable...?" Visible to the naked eye? Microscope? Electron Microscope? The reason that confuses me is because mutations "HAVE" to be, somehow, visible otherwise, how would we even know if one occurred? Right?

[This message has been edited by Milagros, 04-07-2004]


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Coragyps
Member
Posts: 5551
From: Snyder, Texas, USA
Joined: 11-12-2002


Message 40 of 171 (98451)
04-07-2004 3:43 PM
Reply to: Message 39 by Milagros
04-07-2004 3:31 PM


Milagros - mutations can be, and frequently are, changes in DNA that lead to no change in the amino acid that is coded for. Thus, they are "invisible" as far as the organism is concerned: only DNA sequencing can detect them.

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DC85
Member (Idle past 113 days)
Posts: 876
From: Richmond, Virginia USA
Joined: 05-06-2003


Message 41 of 171 (98456)
04-07-2004 4:06 PM


right thats what I mean Coragyps...

I Have some Problems Expressing things... Like Instead of Creature I should have used Organism and Instead of not Visible I should have said almost Undetectable... little mistakes give me problems... I Get yelled at by my Professor all the time.

[This message has been edited by DC85, 04-07-2004]


  
Loudmouth
Inactive Member


Message 42 of 171 (98459)
04-07-2004 4:10 PM
Reply to: Message 39 by Milagros
04-07-2004 3:31 PM


quote:
Also DC85 , what do you mean, "most are not Visable...?" Visible to the naked eye? Microscope? Electron Microscope? The reason that confuses me is because mutations "HAVE" to be, somehow, visible otherwise, how would we even know if one occurred? Right?

Most mutations are neutral. Usually, this refers to mutations of the DNA in areas that do not code for a protein or are not involved with expression of a protein (eg, promoter regions). Also, neutral mutations can change the amino acid sequence of a protein but the activity and specificity of the protein is unaffected. Obviously, without sequencing the DNA or amino acid sequence of the protein these mutations would not be apparent. So yes, they are visible, but not visible with respect to the functioning of the organism, either as an increase in fitness or a decrease in fitness.

Here is a question for the fold. If a mutation causes a change in phenotype, but is neutral with respect to fitness, can this also be considered a neutral mutation? I would assume that this type of mutation would be considered neutral, but was wondering what the uber-experts thought.


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Servus Dei
Inactive Member


Message 43 of 171 (98553)
04-07-2004 8:41 PM
Reply to: Message 31 by crashfrog
04-06-2004 10:59 PM


More Questions...
I have a few more questions:

It seems that it is generally agreed upon that most mutations are neutral, some are harmful, and even fewer are beneficial. It has been said that beneficial simply means that the organism can reproduce faster than its counterparts.

How might one define a mutation? I understand it is the change in allele frequencies, or something like that. What are some common day examples of beneficial mutations in humans? Do we know of any? Do mutations really occur fast enough to lend credibility to the theory of evolution? In other words, are there enough beneficial mutations to explain why humans evolved so quickly into what they are today? Aren't most mutations sterile, or unable to reproduce?

I thought that mutations more often take things away than provide new, helpful things. For example, when mutations take out teeth, that is not exactly beneficial, is it? How would such a thing help faster reproduction (if indeed that is the definition of beneficial)? It seems like when people refer to "beneficial" they mean two things: Helpful to the organism, and able to make reproduction faster and more numerous. Is this equiviating on the term?

And crashfrog, I am sorry I misunderstood. What would you say is the difference between evolution and speciation? Can evolution occur without speciation? If so, what is the organism evolving into that is new? Can there be any significant evolution within a species? Finally, are evolutions and mutations somewhat synomous, or is there no direct relation?


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Servus Dei
Inactive Member


Message 44 of 171 (98557)
04-07-2004 8:47 PM
Reply to: Message 30 by Coragyps
04-06-2004 10:49 PM


Coragyps,

Thanks for the site. Unfortunately, I didn't find any stuff about mutations in it though.


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Coragyps
Member
Posts: 5551
From: Snyder, Texas, USA
Joined: 11-12-2002


Message 45 of 171 (98558)
04-07-2004 8:54 PM
Reply to: Message 43 by Servus Dei
04-07-2004 8:41 PM


Re: More Questions...
What are some common day examples of beneficial mutations in humans?

A few that have shown up on this very forum before:
* two different mutations, one African and one West European, that appear to give near-immunity to AIDS
* a mutation in Italians in a village that make the mutants nearly immune to high-cholesterol problems
* a cluster of mutations which allow adults to continue to digest lactose and thereby drink milk
* the hemoglobin C mutation, which, like sickle-cell, give resistance to malaria, but which usually is otherwise symptomless.

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