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Author Topic:   How is Natural selection a mechanism?
Coyote
Member (Idle past 850 days)
Posts: 6117
Joined: 01-12-2008


Message 3 of 191 (522551)
09-03-2009 10:14 PM
Reply to: Message 1 by AndrewPD
09-03-2009 7:02 PM


Mutating genes
Aren't mutating genes the sole mechanism by which organisms are formed?

No.

Mutations may be harmful, neutral, or beneficial. And, there are many potential mutations that occur at the same time, in varying degrees of harmful, neutral, or beneficial.

Natural selection is the arbiter of which of these mutations, or combination of mutations, are most successful within a particular environment.

And to make matters more complicated, there are changes that occur that don't involve mutations--this field is called epigenetics. Perhaps the biologists here will provide some information on this aspect.

So, the answer to your question is no.


Religious belief does not constitute scientific evidence, nor does it convey scientific knowledge.

This message is a reply to:
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Coyote
Member (Idle past 850 days)
Posts: 6117
Joined: 01-12-2008


Message 23 of 191 (525532)
09-23-2009 5:13 PM
Reply to: Message 19 by Kevin123
09-23-2009 4:09 PM


Biblical creationist zealots
Yet his proposed theory maintains an almost religious following with anybody who even questions them being attacked as a biblical creationist zealot.

That because those are virtually the only folks nowadays who are questioning the theory of evolution.

Science concluded that the theory was the best explanation for the data over a century ago, and there has been no need to revise that conclusion. Rather, the data keep coming in on the side of evolution.

Example: DNA, unknown in Darwin's day, could have shown that Darwin was wrong and that another theory was more accurate. This hasn't happened.

Example: There were almost no hominid fossils recognized when Darwin published in 1859 (the Neanderthal specimen was found only three years earlier, and was not understood at the time). The masses of hominid fossils found since then could have shown that the theory of evolution was incorrect, but instead they have supported it.

And, for the most part, those arguing against the theory of evolution (whether biblical creationist zealots or not) are doing so because of religious, not scientific, reasons. They want the theory to be wrong because they disagree--for religious reasons--with its conclusions.

On natural selection: Here is an experiment. Roll 25 dice in an attempt to get all sixes. If you try to get all 25 dice to show a six on one roll you'll be there for years. However, mutations and natural selection don't work that way. Here is a more accurate way to look at it. Roll those 25 dice, then pick up and reroll any dice that is not a six. You'll have all sixes in just a few minutes. While not a perfect example, that is closer to the way evolution works.


Religious belief does not constitute scientific evidence, nor does it convey scientific knowledge.

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Coyote
Member (Idle past 850 days)
Posts: 6117
Joined: 01-12-2008


Message 27 of 191 (525550)
09-23-2009 5:51 PM
Reply to: Message 25 by Kevin123
09-23-2009 5:42 PM


Re: Mutating genes
This is an incredibly short period of time considering the only evolution we have witnessed is small changes within simple organisms.

Perhaps your view of the time things take is flawed.

How much time would you consider adequate for the evolution of Homo ergaster, Homo erectus, Homo heidelbergensis, and Homo neanderthalensis, the first three of which are most likely in the human line? Paleontologists would put this on the order of two million years.

Would you consider that impossible--just not enough time for it to happen?


Religious belief does not constitute scientific evidence, nor does it convey scientific knowledge.

This message is a reply to:
 Message 25 by Kevin123, posted 09-23-2009 5:42 PM Kevin123 has responded

Replies to this message:
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Coyote
Member (Idle past 850 days)
Posts: 6117
Joined: 01-12-2008


Message 32 of 191 (525562)
09-23-2009 6:53 PM
Reply to: Message 29 by Kevin123
09-23-2009 6:22 PM


Re: Mutating genes
How much time would you consider adequate for the evolution of Homo ergaster, Homo erectus, Homo heidelbergensis, and Homo neanderthalensis, the first three of which are most likely in the human line? Paleontologists would put this on the order of two million years.

So the extremely small (in context) changes from Homo ergaster took 2 million years. They have same basic bone structure and no new organs.

So you consider two million years adequate to accomplish these changes (which amount to speciation)? (The changes may seem to be the "same basic bone structure, etc." but they include a considerable increase in brain size, among other changes.)

Evolution from a multicellular life form to homo ergaster (an exponentially more complex change) took only 300 times as long?

What slowed evolution down?

Perhaps successful adaptation to niches and slower changes in environment. That's not my field so someone else will have to weigh in on that part.


Religious belief does not constitute scientific evidence, nor does it convey scientific knowledge.

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Coyote
Member (Idle past 850 days)
Posts: 6117
Joined: 01-12-2008


Message 39 of 191 (529797)
10-10-2009 3:09 PM
Reply to: Message 37 by Kevin123
10-10-2009 2:35 PM


Re: Mutating genes
...there has never been a mutation observed (in nature, or in a lab) that has not corrected itself.

Please provide a source for this. (And don't bother citing creationist websites; they lie.)


Religious belief does not constitute scientific evidence, nor does it convey scientific knowledge.

This message is a reply to:
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Coyote
Member (Idle past 850 days)
Posts: 6117
Joined: 01-12-2008


Message 41 of 191 (529836)
10-10-2009 7:06 PM
Reply to: Message 40 by Kevin123
10-10-2009 6:41 PM


Re: Mutating genes
...give me a source for a beneficial permanent mutation that's resulted in new genetic information for any animal or insect/

That's easy! Here is a fine example:

Historical contingency and the evolution of a key innovation in an experimental population of Escherichia coli

Zachary D. Blount, Christina Z. Borland, and Richard E. Lenski

Abstract: The role of historical contingency in evolution has been much debated, but rarely tested. Twelve initially identical populations of Escherichia coli were founded in 1988 to investigate this issue. They have since evolved in a glucose-limited medium that also contains citrate, which E. coli cannot use as a carbon source under oxic conditions. No population evolved the capacity to exploit citrate for >30,000 generations, although each population tested billions of mutations. A citrate-using (Cit+) variant finally evolved in one population by 31,500 generations, causing an increase in population size and diversity. The long-delayed and unique evolution of this function might indicate the involvement of some extremely rare mutation. Alternately, it may involve an ordinary mutation, but one whose physical occurrence or phenotypic expression is contingent on prior mutations in that population. We tested these hypotheses in experiments that “replayed” evolution from different points in that population's history. We observed no Cit+ mutants among 8.4 × 1012 ancestral cells, nor among 9 × 1012 cells from 60 clones sampled in the first 15,000 generations. However, we observed a significantly greater tendency for later clones to evolve Cit+, indicating that some potentiating mutation arose by 20,000 generations. This potentiating change increased the mutation rate to Cit+ but did not cause generalized hypermutability. Thus, the evolution of this phenotype was contingent on the particular history of that population. More generally, we suggest that historical contingency is especially important when it facilitates the evolution of key innovations that are not easily evolved by gradual, cumulative selection.

http://www.pnas.org/content/105/23/7899.abstract

Now I know that creationists like to pretend this is not new genetic information, and that it is just adaptation. Unfortunately, that isn't true and repetition won't make it true.


Religious belief does not constitute scientific evidence, nor does it convey scientific knowledge.

This message is a reply to:
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Coyote
Member (Idle past 850 days)
Posts: 6117
Joined: 01-12-2008


Message 50 of 191 (529882)
10-10-2009 10:06 PM
Reply to: Message 45 by Kevin123
10-10-2009 9:32 PM


Re: Mutating genes
The problem is you people always resort to the same three things every time: this bacteria learnt to eat that, became resistant to that, sickle cell this....

These are examples of evolution.

Its not our fault that creationists expect evolution to be something on the order of a crocodile giving birth to a chicken. If we were to find such an occurrence, then much of what we know about evolution would probably be wrong.

And if you think that macro evolution is a result of small mutations then the example he provided is your proof.

Macro-evolution (primarily a creationist term now) is the result of many small mutations, or micro-evolutions. Creationists dispute this, but they have never been able to propose a mechanism that halts micro-evolutions when they add up, lest they become a macro-evolution.

Or do you have better proof for how a new organ or limb could be developed?

That's been observed in the fossil record, which is confirmed by the genetic record.

If not then you need to reconcile the mutations observed with the time allowed by your evolutionary timeline.

That's no problem.

Even many creationists have no problem with the timeline. Woodmorappe and Lubenow, for example, see Homo ergaster, Homo erectus, Homo heidelbergensis, and Homo neanderthalensis as racial variants of modern man descended from Adam and Eve, most likely arising after the separation of people groups after Babel. This puts the rate of evolution several hundred times faster than that proposed by paleontologists (and in reverse). So if you want to dispute the timeline, better start with creationists. (We'll take on the winner--except in religious battles there are no winners, there are only schisms and more denominations).


Religious belief does not constitute scientific evidence, nor does it convey scientific knowledge.

This message is a reply to:
 Message 45 by Kevin123, posted 10-10-2009 9:32 PM Kevin123 has not yet responded

  
Coyote
Member (Idle past 850 days)
Posts: 6117
Joined: 01-12-2008


Message 55 of 191 (529901)
10-11-2009 12:56 AM
Reply to: Message 52 by Kaichos Man
10-11-2009 12:01 AM


Re: Biblical creationist zealots
That because those are virtually the only folks nowadays who are questioning the theory of evolution.

Oh, how you wish that was true.

But you can hear the footsteps, can't you, Coyote?

More and more scientists, with better and better qualifications, questioning the theory. More and more people breathing on your fragile little house of cards. More and more hitherto sacred absurdities being exposed by mathematics and observed data. More and more intricacies of DNA being uncovered by the year, consigning your theory firmly into a place of academic fantasy.

Virtually the only folks worldwide who question the theory of evolution are religious fundamentalists. Scientists, up to about 99.9%, accept the theory; the numbers are higher among biological and genetic scientists and much lower among mathematicians and engineers (who are not actually scientists in most cases).

To the point where an American President would consider it appropriate to promote the principle of ID.

That was not his best moment.

Listen to those footsteps, Coyote. Because as they become louder and more insistent they will drown out your athiest dogma and herald an exciting new dawn for true science.

True science? What a joke!

Creationists are trying to define "true science" as any science which does not contradict their religious beliefs.

Sorry, it doesn't work that way. Any field of study which follows the scientific method is a "true" science whether creationist say yea or nay.

And why should we listen to what creationists or fundamentalists say about science anyway? Creationism and religious fundamentalism are the antithesis (that means the opposite) of science.

If we were to do all that the fundamentalists were promoting we would be back in the Dark Ages. Sorry, that time has passed and its not coming back again. We've experienced the Enlightenment, which showed us that we no longer have to kowtow to the shamans.


Religious belief does not constitute scientific evidence, nor does it convey scientific knowledge.

This message is a reply to:
 Message 52 by Kaichos Man, posted 10-11-2009 12:01 AM Kaichos Man has not yet responded

  
Coyote
Member (Idle past 850 days)
Posts: 6117
Joined: 01-12-2008


Message 119 of 191 (816062)
07-28-2017 2:26 PM
Reply to: Message 118 by AndrewPD
07-28-2017 2:09 PM


Scientific dissent? Bah!
Signatories of the Scientific Dissent From Darwinism...

You do realize, don't you, that "Belief gets in the way of learning."

Those who accept a belief in creationism can easily compartmentalize all of their scientific training and "believe six impossible things before breakfast."

When they are applying the creationist "method" (belief) to things they are no longer doing science. To do science one must follow the scientific method, which is the exact opposite.


Religious belief does not constitute scientific evidence, nor does it convey scientific knowledge.

Belief gets in the way of learning--Robert A. Heinlein

In the name of diversity, college student demands to be kept in ignorance of the culture that made diversity a value--StultisTheFool

It's not what we don't know that hurts, it's what we know that ain't so--Will Rogers

If I am entitled to something, someone else is obliged to pay--Jerry Pournelle

If a religion's teachings are true, then it should have nothing to fear from science...--dwise1

"Multiculturalism" demands that the US be tolerant of everything except its own past, culture, traditions, and identity.

Liberals claim to want to give a hearing to other views, but then are shocked and offended to discover that there are other points of view--William F. Buckley Jr.


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