ChatterBank27 mins ago
Theory of Evolution....I don't buy it!!!
May I just ask, in all seriousness, if anyone has 'questioned' the 'theory of evolution'? Personally, I think that coz we have a NEED to know where we came from, we have just jumped onto the 'theory' that seems to sound 'ok' just so we DO have a theory. But have a think about it.....apes evolved into humans.......
1. If apes evolved into humans, why are there still apes?
2. If they do evolve into humans, then why do we not see apes in various stages of evolution today?
3. Did we choose 'apes' because they 'look a bit similar'?
4. If scientists had suggested we evolved from zebras or giraffes, would we be so keen to believe it, or do we accept the monkey theory coz of the similarity to humans?
Animals surely can adapt and evolve, but do they turn into completely different species? No. Do hippos turn into dolphins? Do cats turn into giraffes? Do penguins turn into elephants?
Why can't we just admit we don't know? If someone had come up with this theory in their science homework (assuming it hadn't been said before) you'd be on detention! "Yes miss, I think we evolved from hedgehogs/starfish/apes etc "
1. If apes evolved into humans, why are there still apes?
2. If they do evolve into humans, then why do we not see apes in various stages of evolution today?
3. Did we choose 'apes' because they 'look a bit similar'?
4. If scientists had suggested we evolved from zebras or giraffes, would we be so keen to believe it, or do we accept the monkey theory coz of the similarity to humans?
Animals surely can adapt and evolve, but do they turn into completely different species? No. Do hippos turn into dolphins? Do cats turn into giraffes? Do penguins turn into elephants?
Why can't we just admit we don't know? If someone had come up with this theory in their science homework (assuming it hadn't been said before) you'd be on detention! "Yes miss, I think we evolved from hedgehogs/starfish/apes etc "
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Please explain how I can prepare a chiral compound without chryral input ....... This is V difficult (impossible) even if you aim to do this. Happening spontanoisly? I dont think so.
Re the moon landings - you end up by your approach with the most plausable explanation based on avalible evidence, it is possible that it may not be correct. For example (ans this is a bit of a silly one as I havent the time to work out a sensible one) if it transpired that those involved had placed a large bet on being able to pass of a fraudulent landing ........
In work I have done I have initially decieded that the most simple expalnation is the correct one, but it is not until I re-run the experiment I find that the ans is far more complex ..... with E & the moon landings you can not rerun the experiment therefore there must be an element of belief.
Someone siad that a wise man knows what he does not know. And I think that realising and admiting to the flaws and problems or big asumptions in a theory is key to progressing said theory. At the end of the day we can never know if E is right or not, just claim it is the best scientific model holes and all. Belief and wishful thinking are two differnt things, and I think belief is more prevalent in science than many scientists wish to admit.
Re the moon landings - you end up by your approach with the most plausable explanation based on avalible evidence, it is possible that it may not be correct. For example (ans this is a bit of a silly one as I havent the time to work out a sensible one) if it transpired that those involved had placed a large bet on being able to pass of a fraudulent landing ........
In work I have done I have initially decieded that the most simple expalnation is the correct one, but it is not until I re-run the experiment I find that the ans is far more complex ..... with E & the moon landings you can not rerun the experiment therefore there must be an element of belief.
Someone siad that a wise man knows what he does not know. And I think that realising and admiting to the flaws and problems or big asumptions in a theory is key to progressing said theory. At the end of the day we can never know if E is right or not, just claim it is the best scientific model holes and all. Belief and wishful thinking are two differnt things, and I think belief is more prevalent in science than many scientists wish to admit.
Hamish
I'm not suggesting that it would be easy otherwise scientists would have recreated life in the lab. Serine is a compound that naturally forms strong bonds with amino acids of the same chirality.
http://en.wikipedia.org/wiki/Origin_of_life
Sugars and amino acids both exhibit homochirality albeit of different handedness. It is certainly not impossible (see serine, above).
See also:
http://www.nasa.gov/centers/ames/news/releases /2002/02_33AR.html
Re moon landings: "the most plausible explanation based on available evidence". Sort of correct. Only we can be more confident than "most plausible". We could go as far as saying the moon landings are a fact and to disprove that assumption you are going to need some pretty strong evidence (as opposed to some wild speculation).
You certainly can rerun the experiment with the moon landings and with evolution. Evolution experiments are ongoing and the moon is to be revisited.
I think you have shown that belief has many interpretations and I agree with you that scientists hold beliefs and make assumptions. The thing is, they have to back up their beliefs with that pesky evidence. Evolution is based on a theory that has been tested over and over again and never falsified. backed up by the fossil record, backed up by contemporary studies of speciation and backed up by genetics.
I'm not suggesting that it would be easy otherwise scientists would have recreated life in the lab. Serine is a compound that naturally forms strong bonds with amino acids of the same chirality.
http://en.wikipedia.org/wiki/Origin_of_life
Sugars and amino acids both exhibit homochirality albeit of different handedness. It is certainly not impossible (see serine, above).
See also:
http://www.nasa.gov/centers/ames/news/releases /2002/02_33AR.html
Re moon landings: "the most plausible explanation based on available evidence". Sort of correct. Only we can be more confident than "most plausible". We could go as far as saying the moon landings are a fact and to disprove that assumption you are going to need some pretty strong evidence (as opposed to some wild speculation).
You certainly can rerun the experiment with the moon landings and with evolution. Evolution experiments are ongoing and the moon is to be revisited.
I think you have shown that belief has many interpretations and I agree with you that scientists hold beliefs and make assumptions. The thing is, they have to back up their beliefs with that pesky evidence. Evolution is based on a theory that has been tested over and over again and never falsified. backed up by the fossil record, backed up by contemporary studies of speciation and backed up by genetics.
Dawkins, thanks for continuting the chat. I guess you are not your names sake or you would have understood the problem with chirality. All life had only one handedness - this cannot spontanoiusly form.
Yes you can make a recemic mixture of chiral compounds, but then life would consist of a similar mixutre. It is not possible to prepare a homochiral compound without a chiral imput - and even in the lab this is v difficult. Anyone claiming apparent spontanous chirality (like the chap who claimed that the magnetic field from his hot plate cause a increase in one enatiomer) would be very seriously scrutinised.
I agree that scientists look at evidence and belief in diffent ways and settle for differnt levels of evidence. I am a chemist (as you might have guessed). With respect to rerunning the experiments.....We can create situation wich we believe (think) were present in the past, but in doing so we add a huge number of assumptions. Furthermore it has all got to link together - it go from "nothing" into life that is sat wondering what "nothing" really means. In order to really check it we need a rerun of time - it seems unlikely we will be there to observe it if it happens natrually but lets wiat and see.
I think the thing that worries me as a scientist is that people are taught E as if it were "fact" when there are more assumptions and doubts over its various aspects than over some of the work I have done and cannot yet publish because the referees will (quite rightly) throw it out because of a lack of evidence. In chem the excuse that it is difficult or impossible to measure A or B is not a licence to say - "therefore comound D acts as" rather than, "we think that comound D may act as"....
Yes you can make a recemic mixture of chiral compounds, but then life would consist of a similar mixutre. It is not possible to prepare a homochiral compound without a chiral imput - and even in the lab this is v difficult. Anyone claiming apparent spontanous chirality (like the chap who claimed that the magnetic field from his hot plate cause a increase in one enatiomer) would be very seriously scrutinised.
I agree that scientists look at evidence and belief in diffent ways and settle for differnt levels of evidence. I am a chemist (as you might have guessed). With respect to rerunning the experiments.....We can create situation wich we believe (think) were present in the past, but in doing so we add a huge number of assumptions. Furthermore it has all got to link together - it go from "nothing" into life that is sat wondering what "nothing" really means. In order to really check it we need a rerun of time - it seems unlikely we will be there to observe it if it happens natrually but lets wiat and see.
I think the thing that worries me as a scientist is that people are taught E as if it were "fact" when there are more assumptions and doubts over its various aspects than over some of the work I have done and cannot yet publish because the referees will (quite rightly) throw it out because of a lack of evidence. In chem the excuse that it is difficult or impossible to measure A or B is not a licence to say - "therefore comound D acts as" rather than, "we think that comound D may act as"....
Hamish
As "a chemist" and "a scientist" you would not be arguing about the "impossibility of chirality" in living organisms and you most likely would have followed the links that I provided which would guide you through straight forward examples of how left handed chirality may have developed in organisms. As you may be aware, nonbiological synthesis of chiral molecules produces equel amounts of left and right handedness so it is not, as you incorrectly stated, that homochirality is a problem for the origin of life per se, but rather, that it is a puzzle that life should organise itself with left handed amino acids and right handed sugars. There are various theories of how this state of affairs came about and as way of example I gave you serine which you chose to ignore.
While we are taking slights at each other concerning our scientific acumen please bare in mind that to be understood properly you must endeavour to develop a reasoned argument based on the subject in hand. You bring up chirality which is a puzzle for the origin of life (see the NASA link) and lump evolution in with it. You are as yet unable to give a decent argument of problems with the theory of evolution itself. On the same basis as your argument we must also chuck out the big bang model of the universe because we do not yet have an explanation of its origin.
So to summarise: We have homochirality which is a puzzle for the origin of life, not evolution, but which occurs in nonbiological synthesis of molecules albeit in equal measure of left and right handedness. Serine is an example of an amino acid that forms particularly strong bonds with amino acids of the same charity. Scientists at Purdue have identified serine as the likely root cause of homochirality in organic molecules:
http://www.purdue.edu/UNS/html4ever/030805.Coo ks.chiral.html
As "a chemist" and "a scientist" you would not be arguing about the "impossibility of chirality" in living organisms and you most likely would have followed the links that I provided which would guide you through straight forward examples of how left handed chirality may have developed in organisms. As you may be aware, nonbiological synthesis of chiral molecules produces equel amounts of left and right handedness so it is not, as you incorrectly stated, that homochirality is a problem for the origin of life per se, but rather, that it is a puzzle that life should organise itself with left handed amino acids and right handed sugars. There are various theories of how this state of affairs came about and as way of example I gave you serine which you chose to ignore.
While we are taking slights at each other concerning our scientific acumen please bare in mind that to be understood properly you must endeavour to develop a reasoned argument based on the subject in hand. You bring up chirality which is a puzzle for the origin of life (see the NASA link) and lump evolution in with it. You are as yet unable to give a decent argument of problems with the theory of evolution itself. On the same basis as your argument we must also chuck out the big bang model of the universe because we do not yet have an explanation of its origin.
So to summarise: We have homochirality which is a puzzle for the origin of life, not evolution, but which occurs in nonbiological synthesis of molecules albeit in equal measure of left and right handedness. Serine is an example of an amino acid that forms particularly strong bonds with amino acids of the same charity. Scientists at Purdue have identified serine as the likely root cause of homochirality in organic molecules:
http://www.purdue.edu/UNS/html4ever/030805.Coo ks.chiral.html
My appologies for not checking the link.
Reading the paper (and I only had time for a quick glance) you will see that they use qudrapole and octapole ESMS a system wich induces a spiral of ions in the MS....A source of chirality???
You cannot have a homochyral mixture of two optical isomers, this is a racemic mixture.
As to E, it depends on where you start. I have always looked at it as a whole theory of the origins of life, but you seem only concerned with the cell to man etc step? This still I think leaves the problem of mutation form one species into another......
Reading the paper (and I only had time for a quick glance) you will see that they use qudrapole and octapole ESMS a system wich induces a spiral of ions in the MS....A source of chirality???
You cannot have a homochyral mixture of two optical isomers, this is a racemic mixture.
As to E, it depends on where you start. I have always looked at it as a whole theory of the origins of life, but you seem only concerned with the cell to man etc step? This still I think leaves the problem of mutation form one species into another......
First the homochirality issue:
Miller-Urey showed in 1953 that amino acids could be formed from inorganic precursors albeit in racemic mixtures. Their experiment yielded 13 of the 21 amino acids that are used to make proteins in living cells. Recent studies have concluded that in "old" areas of genes that are most remote between extant species are rich in the miller-urey amino acids. This is evidence that originally life was based on fewer amino acids. but how did the homochirality come about? I have already mentioned serine which you seem to be ignoring but there is also much research into chiral amplification in autocatalytic reactions. Recent research by Julius Rebek and others have demonstrated that autocatylists offer a good model for the origin of life. In particular something like RNA could have autocatalysed its own synthesis and evolved from there. We, of course, do not know yet the exact process so this is a hypothesis and not a theory. To claim that it is impossible is, however, not true. It is also an argument from ignorance.
cont...
Miller-Urey showed in 1953 that amino acids could be formed from inorganic precursors albeit in racemic mixtures. Their experiment yielded 13 of the 21 amino acids that are used to make proteins in living cells. Recent studies have concluded that in "old" areas of genes that are most remote between extant species are rich in the miller-urey amino acids. This is evidence that originally life was based on fewer amino acids. but how did the homochirality come about? I have already mentioned serine which you seem to be ignoring but there is also much research into chiral amplification in autocatalytic reactions. Recent research by Julius Rebek and others have demonstrated that autocatylists offer a good model for the origin of life. In particular something like RNA could have autocatalysed its own synthesis and evolved from there. We, of course, do not know yet the exact process so this is a hypothesis and not a theory. To claim that it is impossible is, however, not true. It is also an argument from ignorance.
cont...
Evolution is separate from the above because it is a theory with long-standing, robust, corroborating evidence, i.e. a fact. The further you retreat into the past, the simpler organisms become. Speciation is recorded not just in the fossil record but also through direct observation with extant species. The genetic basis for evolution: of copying errors leading to random mutations providing a survival advantage came after Darwin and Mendel and agrees fully with their work. The genetic make up of species can be predicted and tested based on phylogeny and geography. That is why we share more DNA with an old world monkey than a new world monkey; and even more with a chimpanzee than an old world monkey. The evidence is all there.
I did comment on and read the paper on Serine and demonstrated how the measurement itself could introduce chyrality into the measurement .....
on the subject of ignoring... can you give me an example of one species (alive) mutating into another?
All the evidence sited are all observations wich may be supported by E it it by them. However for E to be correct it must allow for one species to mutate into another - a key step wich should be possible to replicate in a living organisum.
on the subject of ignoring... can you give me an example of one species (alive) mutating into another?
All the evidence sited are all observations wich may be supported by E it it by them. However for E to be correct it must allow for one species to mutate into another - a key step wich should be possible to replicate in a living organisum.
But you are aware that serine can form strong bonds with all left or all right handed molecules? you are aware of amplification of homochiral amino acids exaggerating any bias? you are aware of autocatalysts? You can see that the evidence proves that it is far from impossible. In fact once homochirality gets started it can run and run and this is proved by experiment.
Speciation:
Modern Studies:
http://www.talkorigins.org/faqs/faq-speciation .html
http://www.talkorigins.org/faqs/speciation.htm l
Intermediate fossils:
Eldredge with Chase 1981: horse fossils "Eocene Hyracotherium with its small size, four toes on the front foot...climbing up the tertiary stratigraphic column of the american west we find the horses becoming progressively bigger with fewer toes and more complicated teeth (modern horses have one on each foot)..." goes on to say "this is not a made up story, these fossils are real. They are in the proper order and found in the exact predicted sequence in the rock record"
many, many more.
Of course dismissing it out of hand is a way to deal with all that pesky evidence. Have you ever had a proper look into it?
Speciation:
Modern Studies:
http://www.talkorigins.org/faqs/faq-speciation .html
http://www.talkorigins.org/faqs/speciation.htm l
Intermediate fossils:
Eldredge with Chase 1981: horse fossils "Eocene Hyracotherium with its small size, four toes on the front foot...climbing up the tertiary stratigraphic column of the american west we find the horses becoming progressively bigger with fewer toes and more complicated teeth (modern horses have one on each foot)..." goes on to say "this is not a made up story, these fossils are real. They are in the proper order and found in the exact predicted sequence in the rock record"
many, many more.
Of course dismissing it out of hand is a way to deal with all that pesky evidence. Have you ever had a proper look into it?
1. If apes evolved into humans, why are there still apes?
The reason for this is that we did not evolve from modern day apes, there are many kinds of apes, and and through the fossil record, there is evidence that proves to us that other branches of the ape family tree started to evolve, and that these branches had met a dead end with extinction.
2. If they do evolve into humans, then why do we not see apes in various stages of evolution today?
Because we were not descended from those actual branches of the ape family tree, we know for a fact that we are descended from apes though. Even the chromosome argument no longer works against evolution.
3. Did we choose 'apes' because they 'look a bit similar'?
No, we chose apes through evidence in the fossil record, and scientists have genetically proven that we came from apes. It's so firmly proven that four times as many historians believe the holocaust never happened, than scientists think evolution never happened. Plus, Theistic Evolution now exists so religious people can incorporate it with their religious beliefs, it's that solid. Something which the creation theory has never been. In fact there are plenty of 'Theistic Evolutionists', but very few of the original 'Creation Scientists', that followed the book of Genesis, so there must be something good about evolution.
The reason for this is that we did not evolve from modern day apes, there are many kinds of apes, and and through the fossil record, there is evidence that proves to us that other branches of the ape family tree started to evolve, and that these branches had met a dead end with extinction.
2. If they do evolve into humans, then why do we not see apes in various stages of evolution today?
Because we were not descended from those actual branches of the ape family tree, we know for a fact that we are descended from apes though. Even the chromosome argument no longer works against evolution.
3. Did we choose 'apes' because they 'look a bit similar'?
No, we chose apes through evidence in the fossil record, and scientists have genetically proven that we came from apes. It's so firmly proven that four times as many historians believe the holocaust never happened, than scientists think evolution never happened. Plus, Theistic Evolution now exists so religious people can incorporate it with their religious beliefs, it's that solid. Something which the creation theory has never been. In fact there are plenty of 'Theistic Evolutionists', but very few of the original 'Creation Scientists', that followed the book of Genesis, so there must be something good about evolution.
4. If scientists had suggested we evolved from zebras or giraffes, would we be so keen to believe it, or do we accept the monkey theory coz of the similarity to humans?
Scientists never just stated any of that, they have provided near irrefutable evidence. They wouldn't just claim something like 'we evolved from zebras' because they would need evidence for it, and we know via evidence that there is no way that could possibly happen anyway because of differences in the DNA. The description you have given in the question matches that of a religious method, as religion documents a certain belief, and then it is the choice of the people as to whether they want to believe or not, but sadly, it is a blind choice. There is absolutely nothing blind about trusting in something scientific, unless it is a very vague theory, which evolution is not.
Here's a channel on youtube that you may wish to look at:
https://www.youtube.com/user/potholer54
Scientists never just stated any of that, they have provided near irrefutable evidence. They wouldn't just claim something like 'we evolved from zebras' because they would need evidence for it, and we know via evidence that there is no way that could possibly happen anyway because of differences in the DNA. The description you have given in the question matches that of a religious method, as religion documents a certain belief, and then it is the choice of the people as to whether they want to believe or not, but sadly, it is a blind choice. There is absolutely nothing blind about trusting in something scientific, unless it is a very vague theory, which evolution is not.
Here's a channel on youtube that you may wish to look at:
https://www.youtube.com/user/potholer54
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