Understanding through Discussion


Welcome! You are not logged in. [ Login ]
EvC Forum active members: 109 (8802 total)
Current session began: 
Page Loaded: 11-19-2017 2:33 PM
355 online now:
Coyote, halibut, PaulK, Percy (Admin), ringo, Tangle (6 members, 349 visitors)
Chatting now:  Chat room empty
Newest Member: jaufre
Upcoming Birthdays: DC85
Post Volume:
Total: 822,676 Year: 27,282/21,208 Month: 1,195/1,714 Week: 38/365 Day: 38/40 Hour: 1/9

Announcements: Reporting debate problems OR discussing moderation actions/inactions


Thread  Details

Email This Thread
Newer Topic | Older Topic
  
1
23456
...
13NextFF
Author Topic:   How is Natural selection a mechanism?
AndrewPD
Member (Idle past 4 days)
Posts: 133
From: Bristol
Joined: 07-23-2009


Message 1 of 191 (522519)
09-03-2009 7:02 PM


Aren't mutating genes the sole mechanism by which organisms are formed?
Replies to this message:
 Message 3 by Coyote, posted 09-03-2009 10:14 PM AndrewPD has not yet responded
 Message 4 by dwise1, posted 09-04-2009 2:03 AM AndrewPD has not yet responded
 Message 5 by dwise1, posted 09-04-2009 2:47 AM AndrewPD has not yet responded
 Message 9 by Dr Adequate, posted 09-04-2009 5:22 PM AndrewPD has not yet responded
 Message 169 by RAZD, posted 08-05-2017 12:21 PM AndrewPD has responded

    
Adminnemooseus
Director
Posts: 3830
Joined: 09-26-2002


Message 2 of 191 (522545)
09-03-2009 9:46 PM


Thread Copied from Proposed New Topics Forum
Thread copied here from the How is Natural selection a mechanism? thread in the Proposed New Topics forum.
    
Coyote
Member
Posts: 6025
Joined: 01-12-2008
Member Rating: 2.3


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:
 Message 1 by AndrewPD, posted 09-03-2009 7:02 PM AndrewPD has not yet responded

Replies to this message:
 Message 12 by Kevin123, posted 09-22-2009 11:13 PM Coyote has not yet responded

  
dwise1
Member
Posts: 2994
Joined: 05-02-2006
Member Rating: 3.2


Message 4 of 191 (522566)
09-04-2009 2:03 AM
Reply to: Message 1 by AndrewPD
09-03-2009 7:02 PM


I think this was mentioned before, that some creationist classes require its students to join forums and make a set number of posts "challenging" evolution. What was that number? 20?

Where are you attending and which class is this for?

Now, let's try something really bizaare and unexpected. How's about you actually try to learn what evolution is and what evolutionary theory says? That would really throw a wrinkle in your professor's plans, since his goal depends on keeping you ignorant of what evolution really is.

PS
OK, first you apparently revived Darwin's mistaken "pangene" ideas, which were based on his misunderstanding of heredity (since they didn't yet know about Mendel's work -- I'll post about that on that thread). Now you try to claim that mutation is all there is to evolution and natural selection has nothing to do with it -- which seems to harken back to the early 20th century when mutations were thought to be it, but then the Grand Synthesis circa 1940 united genetics with natural selection via the mathematical study of population genetics.

So far, all you're offerring is gross misconceptions which look an awful lot like a troll's flame-bait. Do you really have no idea what evolution is about? OK, it should be a given that a creationist has no idea what evolution really is. But are your opening posts really what you think evolution is?

If so, then you have a lot to learn. Are you here to learn? If you are, then a lot of members here will be more than happen to educate you. Including a lot of former creationists who learned the truth.

Edited by dwise1, : PS


This message is a reply to:
 Message 1 by AndrewPD, posted 09-03-2009 7:02 PM AndrewPD has not yet responded

    
dwise1
Member
Posts: 2994
Joined: 05-02-2006
Member Rating: 3.2


Message 5 of 191 (522567)
09-04-2009 2:47 AM
Reply to: Message 1 by AndrewPD
09-03-2009 7:02 PM


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

No. In the early 20th century, geneticists rejected Darwin, in large part because of his mistaken ideas about heredity, and they had discovered mutations. So they pursued the idea that evolution was all through mutation, an idea that has been perpetuated through popular media, such as the X-Men movies.

But then in the 1930's and 1940's, biologists realized that mutations were only one mechanism for increasing the variability of a population's gene pool, whereas it was natural selection that still drove evolution by working on that variability. Thus was the Grand Synthesis and thus was neo-Darwinism.

AndrewPD, we've known for more than 70 years that it's more than just mutations. Isn't it time that you came up to speed on what's what?

One of the products of that Grand Synthesis (or, more properly, part of what had brought about that Synthesis) was population genetics, the mathematical study of how genes spread through a population. Which is key to answering your other question about new traits getting "diluted" (which harkens back to Darwin's misunderstanding of heredity and which led to his mistaken theory of "pangenes").

May I suggest a book? Blueprints: Solving the Mystery of Evolution by Maitland A. Eddey and Donald C. Johanson, Penguin, 1989. It goes through the history of the development of the ideas about evolution. It even gets into the reasoning and the experiments behind the different ideas and discoveries. If your Christian college is at all honest, then you should be able to find it in your library. If it's not there, then look for it in a local state-run college or university's library.

Now for a really heretical thought: Truth is truth; facts are facts.

If your theology really embodies Truth, then why does it need to lie about the facts? Does the Truth ever need to depend on lies?

Now to get really heretical. Instead of using lies and deceptions to attack evolution, why don't you simply learn everything you can about evolution so that you can use evolution's real problems against it? Not the facile lies that creationists teach you, but rather evolution's real problems. But to learn what those are, you will need to actually learn what evolution actually is. And what the evidence actually is. Are you ready for that challenge?

A word of warning. No creationist has ever been able to do that. So far, every creationist who has actually done all that has, to my knowledge, ended up rejecting creationism for being an outrageous pack of lies and deceptions. And I know of none of them who has not left his religion because of it. Sure, some of them have been able to remain Christian, but not fundamentalist Christians. And many of them have followed the dictates of their fundamentalist training and have become atheists, but that's the fault of their religion, not of evolution.


This message is a reply to:
 Message 1 by AndrewPD, posted 09-03-2009 7:02 PM AndrewPD has not yet responded

    
AndrewPD
Member (Idle past 4 days)
Posts: 133
From: Bristol
Joined: 07-23-2009


Message 6 of 191 (522586)
09-04-2009 7:01 AM


This question arose in a debate I was having on an unrelated forum about morality. The person I was arguing with said that morality was an epiphenomenon from the mechanism of natural selection.

In this characterisation natural selection just happens to conveniently produce the required survival mechanisms as if it willed it.

But I don't see how something could be selcted for if it wasn't already present due to a mutation?

If I was immune to aids then I could have already developed immunity before I caught the disease. If A species was hit by a deadly virus the survivors couldn't survive unless they were already equipped with immunity.

Someone wouldn't develop fire proof skin after having been burnt.

I am not a creationist advocate etc. I am just very skeptical about evo explanations.

I did a google for "How is natural selection a mechanism" and couldn't find an answer adressing the issue except a philosophical essay that you'd have to pay for.

Now my question appears sixth on a google search.


Replies to this message:
 Message 7 by Granny Magda, posted 09-04-2009 7:38 AM AndrewPD has not yet responded
 Message 8 by NosyNed, posted 09-04-2009 10:50 AM AndrewPD has not yet responded
 Message 10 by Dr Adequate, posted 09-04-2009 5:29 PM AndrewPD has not yet responded
 Message 11 by dwise1, posted 09-04-2009 7:27 PM AndrewPD has not yet responded

    
Granny Magda
Member
Posts: 2352
From: UK
Joined: 11-12-2007
Member Rating: 2.6


Message 7 of 191 (522589)
09-04-2009 7:38 AM
Reply to: Message 6 by AndrewPD
09-04-2009 7:01 AM


Hi Andrew,

quote:
But I don't see how something could be selcted for if it wasn't already present due to a mutation?

You are correct, it couldn't. Initially mutation provides variation and then natural selection gets to work, weeding out the useful mutations from the bad. I think perhaps your problem boils down to the fact that occasionally people use the term "natural selection" to refer to the process of evolution overall, missing out other important factors, such as mutation and genetic drift.

quote:
Now my question appears sixth on a google search.

Don't you just hate it when that happens!

Mutate and Survive


"A curious aspect of the theory of evolution is that everybody thinks he understands it." - Jacques Monod
This message is a reply to:
 Message 6 by AndrewPD, posted 09-04-2009 7:01 AM AndrewPD has not yet responded

    
NosyNed
Member
Posts: 8800
From: Canada
Joined: 04-04-2003
Member Rating: 10.0


Message 8 of 191 (522643)
09-04-2009 10:50 AM
Reply to: Message 6 by AndrewPD
09-04-2009 7:01 AM


Populations
You don't seem to have developed a feel for what goes on let me try please.

There are about 6 billion humans. In a generation each of those reproduces. About half of all reproductions end in failure very early on (maybe many of those failures are due to mutations but we don't know). The other half all carry several (in the 5 to 100 range) brand new mutations. These changes are separate from the new genetics produced by mixing the genes of the parents.

So each generation we get 6 billion new organisms and not all of those will survive and reproduce. That is a lot of chances for selection to work. In only 1,000 years we'll get about 300 billion new genomes.

Humans are a special case of course since a very large percentage do end up reproducing.

How about rats? They reproduce more than once a year and produce litters of (say) 5 (low btw). There are as many of them (or more) than us. They are cranking out perhaps 30 billion new genomes a year and less than 1/4 of them survive. The others are weeded out by bad luck and some are weeded out by natural selection. In 1,000 years we'll get about 30 trillion (30,000,000,000,000) new rats for natural selection to work on.

Natural selection works because nature is very, very, very inefficient. It is utterly wasteful. You see that more with other species where less than 1% of those born survive. There are literally astronomical numbers of new genomes produced each year and almost all of them are cast aside.

You can come up with almost anything if you just keep on trying things with no concern for being efficient. You just keep stirring the pot and seeing what happens.

Natural selection may only have a small effect on survival rates (that depends on the "selection pressure" as compared to just bad or good luck). But with billions and trillions of individuals to try out it can produce changes in the populations with only a small bias to the luck.


This message is a reply to:
 Message 6 by AndrewPD, posted 09-04-2009 7:01 AM AndrewPD has not yet responded

  
Dr Adequate
Member
Posts: 15972
Joined: 07-20-2006
Member Rating: 4.4


Message 9 of 191 (522750)
09-04-2009 5:22 PM
Reply to: Message 1 by AndrewPD
09-03-2009 7:02 PM


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

Try to attain precision of thought.

The sole mechanism by which we can observe organisms being formed is in fact the reproduction of other organisms. "Mutating genes" are possible in this process but not actually necessary.

If you think I am being overly pedantic, you are wrong. Scientific thought requires precision. If someone maintains that E = mc3, they're not nearly right, they've blown the whole thing.

What is it that you wished to say? If you will try to put what you wanted to say in precise terms, you may find that you can see the answer to your own question.

Edited by Dr Adequate, : No reason given.


This message is a reply to:
 Message 1 by AndrewPD, posted 09-03-2009 7:02 PM AndrewPD has not yet responded

  
Dr Adequate
Member
Posts: 15972
Joined: 07-20-2006
Member Rating: 4.4


Message 10 of 191 (522751)
09-04-2009 5:29 PM
Reply to: Message 6 by AndrewPD
09-04-2009 7:01 AM


But I don't see how something could be selcted for if it wasn't already present due to a mutation?

It can't be.

You seem to be exhibiting a typical confusion which I see often in discussions of evolution. It's as though someone were to say: "Cars can't work. How can the steering wheel be a mechanism that directs the car from place to place when it provides no motive power to the car!"

This analogy is rather a good one. Mutations are the engine, natural selection provides the steering.


This message is a reply to:
 Message 6 by AndrewPD, posted 09-04-2009 7:01 AM AndrewPD has not yet responded

  
dwise1
Member
Posts: 2994
Joined: 05-02-2006
Member Rating: 3.2


Message 11 of 191 (522773)
09-04-2009 7:27 PM
Reply to: Message 6 by AndrewPD
09-04-2009 7:01 AM


Rather than try to think of evolution as something abstract and arbitrary, take the time to observe life and how it works.

In a given area/region, there are populations of plants and animals. Within each population there are individuals who are capable of interbreeding. If we were to examine the collective genomes of a population, which we generally call its "gene pool", we would find a degree of variation between the genomes of the individuals. This we refer to as "genetic diversity" or simply as "variability". When individuals mate a produce offspring, their offspring will be very similar to the parents, yet a bit different. Depending on the species' biology, these differences would be largely due to the different possible combinations of genetic material from each parent (eg, in diploid sexual reproduction, such as humans employ, each parent has 23 pairs of chromosomes and it's a crap shoot which chromosome of each pair each parent contributed to the child). However, some of the genetic differences can also be due to genetic mutations (please note that the only mutations that matter in evolution are heritable ones). Thus, the genetic diversity of the gene pool has been increased.

OK, observor, what do you see happening? A lot of offspring are born, yet a lot also never get born. Not every seed germinates and not every fertilized egg comes to full term. But still, there a an awful lot of offspring out there ... at first. But we observe that in most species of animal that most of the offspring do not survive to sexual maturity; in many species, the vast majority do not make it. As we observe, we can see what some of the individual reasons are, even though we cannot observe them all. We can figure out some of the individual traits that enhance an individual's chances of survival, while others can be more challenging to figure out.

That part is what evolutionary theory deals with as natural selection. Natural selection per se produces nothing new, but rather it tends to filter out the existing traits that diminish one's chances for survival. But note that natural selection is not something that actually exists and exerts force, rather it is how we think about the effects of how individuals survive until they have a chance to reproduce or don't. That "don't" can also apply to sexual selection, which is whether the individual will be chosen to mate, something that is so important in some species that it has profound effects on the appearance and behavior of individuals.

Those offspring who do survive to sexual maturity and who get selected to mate then produce their own offspring. Who are very similar to their parents -- ie, whatever traits the parents had which had enhanced their survival, a number of the children should also have -- and yet are a bit different. And so the cycle starts again.

What we observe is an interplay between reproduction which increases variability and selection which diminishes variability. It takes both for evolution to work.

So then evolution is our description of how life works. Even if we had gotten parts of it wrong, life still works the same way it always has.


This message is a reply to:
 Message 6 by AndrewPD, posted 09-04-2009 7:01 AM AndrewPD has not yet responded

    
Kevin123
Junior Member (Idle past 2659 days)
Posts: 23
From: Texas, USA
Joined: 10-11-2008


Message 12 of 191 (525324)
09-22-2009 11:13 PM
Reply to: Message 3 by Coyote
09-03-2009 10:14 PM


Re: Mutating genes
I need all you smart evolutionists to explain something to me.

Coyote claims that mutations can be harmful or beneficial. I believe evolutionists have been trying for decades to produce beneficial mutations in fruit flies. I was not aware they had ever succeeded in creating a mutation that stuck through more than a few generations. Has a beneficial and permanent mutation ever been observed naturally or in labs by the evolutionary biologists attempting to make it happen?

Assuming that beneficial hereditary mutations do occur, even when evolutionists use that in an argument they say it happens very rarely. What I usually hear that given enough time even rare mutations add up to form new organs and animal species. However, that argument doesnít make sense. If beneficial mutations are rare millions of gradual mutations would be exponentially less likely. A more likely scenario might be a mutation causing a monkey suddenly giving birth to a human.

According to evolutionists the first mammal appeared only hundreds of millions of years ago. Since then we are supposed to believe that small incremental mutations resulted in the thousands of mammals that exist today. That would require millions of mutations for each new organ and millions of bone structure variations for hundreds of thousands, if not millions, of intermediary species (and that these millions of intermediary species somehow disappeared from the fossil record).

So if we figure a mammal breeds on average once a year that only allows 200 - 300 million generations for all those consecutive mutations to occur and propagate. You also have to allow many generations for the mutation to become the dominant trait through natural selection.

If a beneficial mutation occurs say once every million times an animal reproduces (despite evidence to the contrary) then the likelihood of just ten consecutive mutations occurring would be 1 in 10^60, fifty consecutive beneficial mutations would occur 1 in 10^300. Even allowing 300 million generations that is still odds of 3 x 10^6 in 10^300, and that is only 50 beneficial mutations not the millions that would be needed. Thatís also not taking into account the hundreds (at least) of generations it would take for natural selection to make the mutation the dominant trait for each new species.

If you argue that the changes occur faster than that then we should have many changes in humans in the last few thousand years or at the very least a new organ or two. Seems to me that a little math and common sense shows how ridiculously impossible evolution is, but I look forward to somebody pointing out my error.


This message is a reply to:
 Message 3 by Coyote, posted 09-03-2009 10:14 PM Coyote has not yet responded

Replies to this message:
 Message 13 by Dr Adequate, posted 09-22-2009 11:48 PM Kevin123 has not yet responded
 Message 14 by Perdition, posted 09-23-2009 11:51 AM Kevin123 has responded

    
Dr Adequate
Member
Posts: 15972
Joined: 07-20-2006
Member Rating: 4.4


Message 13 of 191 (525328)
09-22-2009 11:48 PM
Reply to: Message 12 by Kevin123
09-22-2009 11:13 PM


Re: Mutating genes
I need all you smart evolutionists to explain something to me.

Sure.

Coyote claims that mutations can be harmful or beneficial. I believe evolutionists have been trying for decades to produce beneficial mutations in fruit flies.

You believe wrongly.

I was not aware they had ever succeeded in creating a mutation that stuck through more than a few generations.

What a bizarre statement. Germ-line mutations are by definition heritable, they can't just melt away like the dew in the morning. The only thing that can get rid of a germ-line mutation is another germ-line mutation.

Has a beneficial and permanent mutation ever been observed naturally or in labs by the evolutionary biologists attempting to make it happen?

Yes, of course. Though "observe it happen" would be more accurate than "make it happen". Obviously when one is studying evolution one does not induce the mutations!

Assuming that beneficial hereditary mutations do occur, even when evolutionists use that in an argument they say it happens very rarely. What I usually hear that given enough time even rare mutations add up to form new organs and animal species. However, that argument doesnít make sense. If beneficial mutations are rare millions of gradual mutations would be exponentially less likely.

You have failed to show your working. As a mathematician, I can assure you that you are wrong, but unless you show your working I can't point out your specific error.

A more likely scenario might be a mutation causing a monkey suddenly giving birth to a human.

No, that is fantastically unlikely, but again, unless you show your working, I can't point out your specific error.

According to evolutionists the first mammal appeared only hundreds of millions of years ago. Since then we are supposed to believe that small incremental mutations resulted in the thousands of mammals that exist today. That would require millions of mutations for each new organ and millions of bone structure variations for hundreds of thousands, if not millions, of intermediary species (and that these millions of intermediary species somehow disappeared from the fossil record).

So if we figure a mammal breeds on average once a year that only allows 200 - 300 million generations for all those consecutive mutations to occur and propagate. You also have to allow many generations for the mutation to become the dominant trait through natural selection.

Natural selection or genetic drift, since not all of the mutations tolerated by natural selection are necessarily adaptive.

We can, of course, measure the rate of mutation, and show that it is just what is required to fit the time-frame derived from geology, thus confirming the correctness of evolution.

If a beneficial mutation occurs say once every million times an animal reproduces (despite evidence to the contrary) ...

Which evidence would that be?

... then the likelihood of just ten consecutive mutations occurring would be 1 in 10^60, fifty consecutive beneficial mutations would occur 1 in 10^300. Even allowing 300 million generations that is still odds of 3 x 10^6 in 10^300, and that is only 50 beneficial mutations not the millions that would be needed.

But your calculation of odds applies to your fantasy of "a monkey suddenly giving birth to a human", not to consecutive mutations being fixed by selection or drift.

If you argue that the changes occur faster than that then we should have many changes in humans in the last few thousand years or at the very least a new organ or two. Seems to me that a little math and common sense shows how ridiculously impossible evolution is, but I look forward to somebody pointing out my error.

Your error? Too little math and too little common sense.

Has it ever occurred to you that geneticists know at least as much math as you, have at least as much common sense, and know a darn sight more about genetics? That would be a fact for you to think over.

Edited by Dr Adequate, : No reason given.


This message is a reply to:
 Message 12 by Kevin123, posted 09-22-2009 11:13 PM Kevin123 has not yet responded

Replies to this message:
 Message 51 by Kaichos Man, posted 10-10-2009 11:06 PM Dr Adequate has responded

  
Perdition
Member (Idle past 826 days)
Posts: 1593
From: Wisconsin
Joined: 05-15-2003


Message 14 of 191 (525440)
09-23-2009 11:51 AM
Reply to: Message 12 by Kevin123
09-22-2009 11:13 PM


Re: Mutating genes
With due respect to Dr. Adequate, I think I can point out where your math went wrong. It's right around here:

So if we figure a mammal breeds on average once a year that only allows 200 - 300 million generations for all those consecutive mutations to occur and propagate.

And again:

If a beneficial mutation occurs say once every million times an animal reproduces

You seem to be neglecting to include the fact that every pairing (mating) of genetic material results in at least a few mutations or errors. There may also be some errors that occur during the early stages of gestation, leading to changes within most of the cells of the subsequent animal. Also, many animals give birth to more than one child at a time, increasing the number of mutations occurring. Add to that the fact that every species has more than one breeding pair, in fact, quite possibly millions of breeding pairs, meaning that millions or billions of mutations occur in every breeding/birthing season, per species, and any really bad mutations will never make it to term, or will die shortly thereafter, making the beneficial mutations much more likely to rise to the top, as it were.

So, every child born has some mutations, some help, some hurt, many do nothing overt at the moment. These mutants (every animal ever born is a mutant) then breed with other mutants, adding more mutations. In species that are not monogamous, this mutational spread (or genetic drift) increases, and if a mutation helps an animal breed, even a little bit, that mutation gets spread even farther.

You're not taking into account the sheer number of mutations that occur nor population size considerations. I think you're missing out natural selection as a way of weeding out mutations as well, but I'm not quite sure of this since you didn't explain enough.


This message is a reply to:
 Message 12 by Kevin123, posted 09-22-2009 11:13 PM Kevin123 has responded

Replies to this message:
 Message 15 by Wounded King, posted 09-23-2009 11:57 AM Perdition has responded
 Message 19 by Kevin123, posted 09-23-2009 4:09 PM Perdition has responded

    
Wounded King
Member (Idle past 1683 days)
Posts: 4149
From: Edinburgh, Scotland
Joined: 04-09-2003


Message 15 of 191 (525443)
09-23-2009 11:57 AM
Reply to: Message 14 by Perdition
09-23-2009 11:51 AM


Re: Mutating genes
In species that are not monogamous, this mutational spread (or genetic drift) increases

In population genetics 'genetic drift' is something quite specific, I think the way you are using it here is confusing especially when you go on to essentially conflate selection with 'genetic drift'.

TTFN,

WK


This message is a reply to:
 Message 14 by Perdition, posted 09-23-2009 11:51 AM Perdition has responded

Replies to this message:
 Message 16 by Perdition, posted 09-23-2009 2:01 PM Wounded King has responded

    
1
23456
...
13NextFF
Newer Topic | Older Topic
Jump to:


Copyright 2001-2015 by EvC Forum, All Rights Reserved

™ Version 4.0 Beta
Innovative software from Qwixotic © 2017