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Author Topic:   Arguments against evolution: are they valid?
Tamara
Inactive Member


Message 1 of 23 (85752)
02-12-2004 11:07 AM


I have looked into the claims of animal speciation, and the evidence of actual observed occurence is surprisingly thin. But it does exist. There is a black rat on Mauritius that has a different number of chromosomes from all the other rats in the world, which developed from ship escapees over several hundred years. There are obvious or less obvious morphological changes in various animals such as the finches and other island birds, as well as in insects and fishes. Speciation seems most persuasive in plants. In Drosophila, there have been various claims that seem to do more with "incipient speciation" rather than actual speciation. And an instance of infection by mites actually prevents co-mating between members of the same species.
Speciation, I think, is not a problem per se for the evolutionary theory. It is a clear and observed fact that groups of organisms do diverge when the opportunity presents itself, and this results in groups that are different from the parent group. They may even develop physiological incompatibility in breeding (I have seen it argued that the Mauritius rats would be unable to mate with other rats because their chromosome number is different. But other rat groups also vary in chromosome number, and in any case, sometimes creatures with different chromosomes do mate successfully: the Przewalski's horse produces fertile offspring with Arabian horses. So I am not sure if that claim is valid or not.) In any case, since the concept of species remains fuzzy and plastic, and since organisms clearly do diverge significantly, it seems to me to be a non-issue.
However, the crux of the matter is this. Can such instances of divergence exemplify large scale evolution (the kind that can produce a gorilla from a small shrew-snouted ur-mammal? And how come that in all the long term breeding of Drosophila, where 2+ generations are produced in a month, no clear cut new species has been reported? In laboratory situations, where mutations can be induced with ease, we should have examples of the rare beneficial mutation as well as emergence of clear cut new and better adapted organisms. Yet, there is no super fruit fly at all. There have been various groups of freak and pathetic mutants which make my heart sore, like the flies with extra wings that are non-functional and about as useful as a hole in the head. Or legs growing out of their foreheads, etc. So... it seems to me that if the argument should hold, that natural (or in this case artificial) selection plus mutation can create novel and better creatures, we should have some evidence for it by now from the labs.
Creationists have argued the following:
1) That selection and mutation cannot explain the emergence of novel organisms because beneficial novel mutations is so excruciatingly rare as to be almost non-existent, and selection can only give us more of the same within that genome.
2) That there is a barrier to organisms diverging past a certain point -- called "genetic homeostasis" by Mayr. What this means is that any efforts to cultivate an organism past a certain point will result in non-viability or reverting to original stock. As observed by breeders for centuries, critters bred for milk or meat or speed or other characteristics end up developing disadvantages that balance out the new advantages. Inbreeding results in sick and deformed dogs, or sugar beets that revert to low sugar ancestral pattern, or fruit flies that become sterile and die out.
3) Neither mutation nor selection adds information. When a beetle loses its wings on an island where it is advantageous, or a fish its eyes in a cave, this does not add the sort of information we would need in order for an ur-shrew to become a whale. When a finch grows a bigger stronger beak because of environmental pressures, the information on which these changes are made is already contained in the finch genome.
How valid are these arguments?

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NosyNed
Member
Posts: 8996
From: Canada
Joined: 04-04-2003


Message 2 of 23 (85766)
02-12-2004 11:30 AM
Reply to: Message 1 by Tamara
02-12-2004 11:07 AM


Nope
I'm no expert and I'm a bit rushed but I'll offer my comments on these and wait for real geneticists etc. to comment.
1) That selection and mutation cannot explain the emergence of novel organisms because beneficial novel mutations is so excruciatingly rare as to be almost non-existent, and selection can only give us more of the same within that genome.
It appears that some rather drastic phenological changes can occur with surprising small changes in the genotype. Regulatory parts of the genome can have this affect. Thus "novel" changes may not be so improbable at all.
There is also no way I can see for calculating the actual number of possible 'successful' outcomes. The current set of organisms could, possibly, be replaced by a totally different set and all of them could be just as successful. Do we know how many such sets are possible? No.
Also, I don't see how the actual probability of some viable and potentially beneficial mutation can actually be calculated. It seems that all (non unicellular anyway) organisms, each individual carries some mutations that are at least not harmful enough to be selected out. This is an awfully large number of chances to get it right. Or to wait until environmental changes turn a neutral or even somewhat harmful mutation into something beneficial.
2) That there is a barrier to organisms diverging past a certain point -- called "genetic homeostasis" by Mayr. What this means is that any efforts to cultivate an organism past a certain point will result in non-viability or reverting to original stock. As observed by breeders for centuries, critters bred for milk or meat or speed or other characteristics end up developing disadvantages that balance out the new advantages. Inbreeding results in sick and deformed dogs, or sugar beets that revert to low sugar ancestral pattern, or fruit flies that become sterile and die out.
added by edit -- got lost
When breeding there is no time for mutations to add any changes. It is a form of extreme inbreeding. Without new genetic material it wouldn't be too surprising that there would be some point reached where you can't go further. Also breeders aren't going for overall fitness they are pushing for an extreme and are successful at getting it.
The problem with talking about barriers is that, other than the limits I mention above, no one seems to be able to point to it.
3) Neither mutation nor selection adds information. When a beetle loses its wings on an island where it is advantageous, or a fish its eyes in a cave, this does not add the sort of information we would need in order for an ur-shrew to become a whale. When a finch grows a bigger stronger beak because of environmental pressures, the information on which these changes are made is already contained in the finch genome.
This is clearly wrong. I have yet to see any kind of reasonable definition of information where it can't be added. In fact, somewhere (can't remember) a creationist site noted that if a mutation can "remove information" (to say produce a blind cave fish) then a mutation that was the reverse of that one would have to be defined as adding information. I don't see anything that says one mutation (say an added base messing up a gene for eyes) couldn't be reversed (the base being left out of some copy).
All of above are statments that don't seem to have any backing with more than assertions.
[This message has been edited by NosyNed, 02-12-2004]
[This message has been edited by NosyNed, 02-12-2004]

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Coragyps
Member (Idle past 735 days)
Posts: 5553
From: Snyder, Texas, USA
Joined: 11-12-2002


Message 3 of 23 (85773)
02-12-2004 12:17 PM
Reply to: Message 1 by Tamara
02-12-2004 11:07 AM


Tamara - I'm dragging this out again:
http://EvC Forum: Favorable Mutations? Help me!! -->EvC Forum: Favorable Mutations? Help me!!
It pretty much puts the lie to "no new information," and it's just one example of many.

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Silent H
Member (Idle past 5820 days)
Posts: 7405
From: satellite of love
Joined: 12-11-2002


Message 4 of 23 (85788)
02-12-2004 1:05 PM
Reply to: Message 1 by Tamara
02-12-2004 11:07 AM


quote:
1) That selection and mutation cannot explain the emergence of novel organisms because beneficial novel mutations is so excruciatingly rare as to be almost non-existent, and selection can only give us more of the same within that genome.
I would ask how creationists know this? In two threads of the Intelligent Design forum area, I have given two examples of positive mutations that have emerged within our lifetimes within a plant species and in humans.
Given that they do happen and are seen to provide the protections and advantages that evolutionary theory predicts, that kind of shoots down this commentary.
As far as "more of the same withing that genome" I would point you to that plant thread. It had a changed phenotype, which seems to be the main way creos define "kind". It obviously has a new gene structure (that is how it was identified as a new species). Kind of shoots off the second part of their argument... unless one asks for ridiculous changes such as turning a frog into a mosquito over time. I am uncertain why evolutionary theory cannot include boundaries of credible change.
The point is that from the very simple structure of the prokaryote, genetic change and symbiosis (which you did not address in any of your points) and perhaps as yet undetected mechanisms allowed for simpler organisms to become more complex.
Very complex organisms may yet become even more complex, but there is no reason to believe evolution says ANY very complex organism would be able to change into ANY OTHER complex organism.
quote:
2) That there is a barrier to organisms diverging past a certain point -- called "genetic homeostasis" by Mayr.
This does not remove the possibility of simpler organisms becoming more complex, but merely very complex organisms having a more restricted boundary into which they can change. Over very long periods of time this can still result in drastic change to our eyes.
But this still excludes symbiosis. Mayr wrote the forward to one of Lynn Margulis's book on the subject. While critical of some points (namely her punking on genes being a large part of change), he applauded her research into other mechanisms for organism change. Her research has already been supported by evidence which is pretty hard to deny. Check up on Margulis.
quote:
3) Neither mutation nor selection adds information.
This has been pretty thoroughly spanked. Please present a way to calculate "information". The only one around is Shannon's theory. Then show how it is applied to living systems. In particular, take a crack at calculating the information content of the plants and humans in my threads in the Intelligent Design forum area.
Of course changes work on existing genomes, and eventually those genomes become so changed they are no longer the same genome. I think the example of the evolution of the eye or of the jawbone/ear are good examples. And there are cases where symbiosis occurs and new genomes are combined between two organisms.

holmes
"...what a fool believes he sees, no wise man has the power to reason away.."(D. Bros)

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Roadkill
Inactive Member


Message 5 of 23 (85796)
02-12-2004 1:25 PM
Reply to: Message 1 by Tamara
02-12-2004 11:07 AM


I think the problem with defining the word species is that we really can't... yet. Every rule has exceptions. Some scientists say it's just a human convention, let's just keep changing it around. I think we don't have enough understanding or what it is that we want to define as a species to make that decision. As for labeling Christians as all those who believe God creted things instantaneously (without a Big Bang), or whatever, is also a misnomer. Genesis doesn't mention Big Bang, evolution, or any means by which God created anything, so as a scientist, I can make no comment. However, I see nothing wrong with saying God used evolution/ Big Bang, etc. because He created science. Anything outside of the universe is not science (the supernatural). So why try to connect the two? As a scientist I ponder many questions, but we can't use our arrogant ideas to attack. All we can do is question and know nothing is truly certain. It seems the more we learn of quantum physics, the more confused we get on the macro level of things. I'm not necessarily commenting on this one article, I've been reading many of these forums. Any comments?

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Saviourmachine
Member (Idle past 3554 days)
Posts: 113
From: Holland
Joined: 01-16-2004


Message 6 of 23 (85864)
02-12-2004 4:23 PM
Reply to: Message 1 by Tamara
02-12-2004 11:07 AM


Creationist's commentary
1) That selection and mutation cannot explain the emergence of novel organisms because beneficial novel mutations is so excruciatingly rare as to be almost non-existent
I think the first part is valid, beneficial novel mutations are still rare (a hundred cases? and that in laboratory with high selection pressure).
and selection can only give us more of the same within that genome.
The role of selection is trivial, mutations have to add genetic code.
2) That there is a barrier to organisms diverging past a certain point -- called "genetic homeostasis" by Mayr. What this means is that any efforts to cultivate an organism past a certain point will result in non-viability or reverting to original stock. As observed by breeders for centuries, critters bred for milk or meat or speed or other characteristics end up developing disadvantages that balance out the new advantages. Inbreeding results in sick and deformed dogs, or sugar beets that revert to low sugar ancestral pattern, or fruit flies that become sterile and die out.
I think that every creature have devolved until a certain level, with losing only non-essential functions. Sometimes it's possible to do a step back, but that are exceptions. That's what I'm thinking, don't take it as the truth. I am waiting on a profound survey of a scientist in regard to the matters of information, complexity, evolution and mutation (see also topic 'Evolution and complexity' EvC Forum: Evolution and complexity )
3) Neither mutation nor selection adds information. When a beetle loses its wings on an island where it is advantageous, or a fish its eyes in a cave, this does not add the sort of information we would need in order for an ur-shrew to become a whale. When a finch grows a bigger stronger beak because of environmental pressures, the information on which these changes are made is already contained in the finch genome.
This is nonsence. Adding of information doesn't always show up on the outside. Maybe the beetle is losing its wings thanks to additional genetic code. By the way, mutations can add information.

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KCdgw
Inactive Member


Message 7 of 23 (87395)
02-18-2004 9:50 PM
Reply to: Message 1 by Tamara
02-12-2004 11:07 AM


Genetic Homeostasis
"Genetic Homeostasis" was coined by the geneticist I. Michael Lerner, in the 1950's. It referred to the apparent resistance of some populations to drastic selection by responding with reduced fitness. Lerner explained the phenomenon this way: drastic artificial selection by man for certain traits disrupted coadapted gene complexes that had evolved over long periods of time in a vastly different environmental context.
Your source didn't claim that Mayr coined the term, did it?
KC

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Taqless
Member (Idle past 5914 days)
Posts: 285
From: AZ
Joined: 12-18-2003


Message 8 of 23 (87407)
02-19-2004 12:20 AM
Reply to: Message 1 by Tamara
02-12-2004 11:07 AM


I apologize for the length of this post beforehand.
1)
This is somewhat incorrect imo.
- I will provide a comparison between the fruit fly drosophila melanogaster and humans using the Hox gene family.
- These genes are highly conserved and the expression pattern during embryonic development is parallel WITH THE EXCEPTION that humans have more copies (in a rough 1:3 ratio which coincides nicely with each respective organism's genome size) of most, we also have a few that the fruit fly does not have as well as missing a couple (truth in explanation this is).
- Why this family of genes? They are responsible for anterior to posterior orientation of cell alignment during development in embryonic humans, mice, and the fruit fly (others as well). This means that depending on the cell's location (each has the same DNA you realize) depending on what hox protein is expressed tells the cell what to "make" at that location (arm, leg, head, etc).
- So, what is the implication of those experiments you saw that "make (your) heart sore"? This could mean that if that protein is expressed for longer intervals, different times, than in the fruit fly it could result in a larger appendage. There are other cell types and proteins responsible for the actual details of the appendage, btw, but the gross formation is what I am driving at. Since this gross development seems to be of highest concern to people that have a difficult time imagining the probability of this evolution occurring.
Remember that what is beneficial to one organism might be deleterious to another it all depends on the perspective. So, that is how I think it is possible for relatively few mutations to result in major phenotypic changes. However, that is from a "just getting started scientist's perspective" NOT a seasoned evolutionary biologist's.
2)
There is an article in Science, 19 December 2003:
EVOLUTION:
Climb Every Mountain?
Santiago F. Elena and Rafael Sanjun
I think this might address or be another explanation for the phenomenon you mention. However, I'm not the strongest by any stretch when it comes to the field of evolution.
3)
When you say "in the same genome" you are actually describing MANY genomes at the same time, but with minor variations.
In the end if it is possible for the field of evolution to somehow incorporate them, since it is my understanding that at this time the introns are NOT considered as well as elements such as enhancers, this might prove to elucidate even more information about life's prehistory. The genome is obviously important in evolution, BUT since in humans alone the gene to protein ratio is ~1:3 (30K-40K genes compared to ~100,000 proteins) the proteome is VERY dynamic as well. I won't even go into non-translated transcripts that have function, but no protein. If you get myopic you will never see the big picture. So, big surprise, no I don't think the arguments are valid because most of the approaches I've seen tell "half a story" for simplicity's sake (imo, look to the OJ Simpson trial as an obvious case in point of people NOT comprehending scientific "mumbo-jumbo". I mean the PCR data specifically).
[This message has been edited by Taqless, 02-19-2004]

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Black
Member (Idle past 5184 days)
Posts: 77
Joined: 11-28-2008


Message 9 of 23 (88782)
02-26-2004 8:51 AM


Reply to Tamara
Hi there Tamara,
Thanks for your post. I will try to summarize your questions and answer them.
>However, the crux of the matter is this. Can such instances of divergence exemplify large scale
>evolution (the kind that can produce a gorilla from a small shrew-snouted ur-mammal?
Actually specification itself would not create everything we see here today (I'll get to this in a minute), but it helps very much.
>And how come that in all the long term breeding of Drosophila, where 2+ generations are produced in a >month, no clear cut new species has been reported?
I am not sure which expirement you are refering to. However, I can say that there are many reasons why it might not have worked (they may have been testing to see if certain conditions would help specification and they did not, etc.)
>In laboratory situations, where mutations can be induced with ease, we should have examples of the >rare beneficial mutation as well as emergence of clear cut new and better adapted organisms.
Good point, Tamara. And in fact, we do (of course, creationist videos wont tell you this).
>Yet, there is no super fruit fly at all. There have been various groups of freak and pathetic mutants which
>make my heart sore, like the flies with extra wings that are non-functional and about as useful as a hole
>in the head. Or legs growing out of their foreheads, etc. So... it seems to me that if the argument should
>hold, that natural (or in this case artificial) selection plus mutation can create novel and better creatures,
>we should have some evidence for it by now from the labs.
Another good point. However, Tamara, the creationists will not tell you about all the successes scientists have. I suggest you go to a website like nature.com and do some research yourself.
>Creationists have argued the following:
>
>1) That selection and mutation cannot explain the emergence of novel organisms because beneficial
>novel mutations is so excruciatingly rare as to be almost non-existent, and selection can only give us
>more of the same within that genome.
Untrue. I can prove this is false because we have seen many, many beneficial mutations. We have even seen NEW PROTEINS formed! Mutations CAN and WILL do the things that creationists claim are impossible.
>2) That there is a barrier to organisms diverging past a certain point -- called "genetic homeostasis" by
>Mayr. What this means is that any efforts to cultivate an organism past a certain point will result in
>non-viability or reverting to original stock. As observed by breeders for centuries, critters bred for milk or
>meat or speed or other characteristics end up developing disadvantages that balance out the new
>advantages. Inbreeding results in sick and deformed dogs, or sugar beets that revert to low sugar
>ancestral pattern, or fruit flies that become sterile and die out.
Enter time plus beneficial mutations (which creationists much ignore fervently). Mutations will and have created new information, new proteins, new metabolic pathways, etc.
>3) Neither mutation nor selection adds information. When a beetle loses its wings on an island where it is
>advantageous, or a fish its eyes in a cave, this does not add the sort of information we would need in
>order for an ur-shrew to become a whale. When a finch grows a bigger stronger beak because of
>environmental pressures, the information on which these changes are made is already contained in the
>finch genome.
Of course these are the ones creationists tell you about. They do not mention the new proteins, single-to-multicellularity, and the boatloads of other beneficial mutations that violated all their "information laws" as I believe they like to call them.
>How valid are these arguments?
In short, Tamara, not valid at all. In fact they are quite deceptive. One thing I suggest you do, Tamara. Is read up on what has actually been done (read the science literature), instead of watching creationist videos....you will learn what actually goes on in science and you will learn that those millions and millions o f evolutionists are not as dump as creationists would like them to be.
I aprpreciate your question (although creationists wouldnt). Questioning is good. Questioning is what got us out of the Dark Ages.
If you have more questions, Tamara,or if you want more information on what I mentioned here let me know (or do the research yourself).
[This message has been edited by Black, 02-26-2004]

  
MarkAustin
Member (Idle past 3815 days)
Posts: 122
From: London., UK
Joined: 05-23-2003


Message 10 of 23 (88794)
02-26-2004 9:51 AM
Reply to: Message 1 by Tamara
02-12-2004 11:07 AM


quote:
Creationists have argued the following:
1) That selection and mutation cannot explain the emergence of novel organisms because beneficial novel mutations is so excruciatingly rare as to be almost non-existent, and selection can only give us more of the same within that genome.
Favourable mutations are rare, but nothing like as rare as creationists argue. (consider, for example, the nylon-eating bacteria)
quote:
2) That there is a barrier to organisms diverging past a certain point -- called "genetic homeostasis" by Mayr. What this means is that any efforts to cultivate an organism past a certain point will result in non-viability or reverting to original stock. As observed by breeders for centuries, critters bred for milk or meat or speed or other characteristics end up developing disadvantages that balance out the new advantages. Inbreeding results in sick and deformed dogs, or sugar beets that revert to low sugar ancestral pattern, or fruit flies that become sterile and die out.
As has been said, the genetic homeostatis argument only applies to gross evolutionary jumps. Given gradual evolution the question is rather: "What mechanism prevents vole-like proto-mammal to gorilla evolution". Much play is made of micro vs macro evoltion, but, to evolutionary scientists, these are the same thing, except that macro-evolution results in a new species. It is incumbent on those challenging evolution to explain how this is prevented.
quote:
3) Neither mutation nor selection adds information. When a beetle loses its wings on an island where it is advantageous, or a fish its eyes in a cave, this does not add the sort of information we would need in order for an ur-shrew to become a whale. When a finch grows a bigger stronger beak because of environmental pressures, the information on which these changes are made is already contained in the finch genome.
Mutations add information (no matter how it is defined all the time). We all three (IIRC) different haemoglobin molecules, derived from three different genes, and caused by copying the original. This is, by any definition increased information.
Again I repeat my point: "What mechanism prevents mutations from crossing a particular line?".
How valid are these arguments?

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kendemyer
Inactive Member


Message 11 of 23 (89453)
02-29-2004 7:21 PM


arguments
Dealing with the arguments against creationism are easy. There are no arguments against creationism!
Sincerely,
Ken

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JonF
Member (Idle past 168 days)
Posts: 6174
Joined: 06-23-2003


Message 12 of 23 (89466)
02-29-2004 8:23 PM
Reply to: Message 11 by kendemyer
02-29-2004 7:21 PM


No arguments against creationism?
Thbat's it! Close your eyes, stick your fingers in your ears, and sing "I can't hear you" continuously at the top of your lungs. That way you can honestly say that you can't see or hear any refutations of creationism.

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wj
Inactive Member


Message 13 of 23 (89473)
02-29-2004 9:04 PM


Tamara, the creationist arguments which you presented in message #1 have been refuted repeatedly and thoroughly in this thread. Out of curiosity, are you going to defend the creationist arguments?
[This message has been edited by wj, 03-01-2004]

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wj
Inactive Member


Message 14 of 23 (89655)
03-01-2004 7:42 PM


^^ bump ^^

  
SAGREB
Inactive Member


Message 15 of 23 (89813)
03-02-2004 3:01 PM
Reply to: Message 1 by Tamara
02-12-2004 11:07 AM


Tamara, how do you define what is the molecular border that a new family or order of animals cant arise. Creationists often refer to families as created kinds?
When looking at genomes of even very different spieces the corresponding genes and proteins correspond to each other. It looks just like different mutations on different gene copies have made the morphological difference in adult animal. All animals have HOX-genes for example. We have the same content in the mitochondria.
That animals are different are due to switch on or switch off of certain genes certain times during development, that otherwise are identical.
Bird embryos show tooth buds. But due to mutations on important genes, the tooth development are hindered. This points to an ancestor of birds that had tooth.
http://www2.tulane.edu/EditorialNewsDetails.cfm?Editorial...

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