Interesting article about science and ignorance

[NorthSideSox72]

Having said that, I think the same problem exists with evolution. You can inductively reason all you want that all these bones added up equals what we are today. But simply relying on that is not enough. 10 years ago the scientific world thought DDT was going to ruin the world and kill off every living thing. It didn't. 10 years ago people thought that cell phones were going to cause cancer of the brain. It didn't. There are many more scientific hiccups over history, all of which used inductive reasoning to arrive at their conclusion, most of which are proven to be false today.

 

These are two interesting parallels, but I need to point out a couple things. One, DDT didn't kill off as many things as it could have because we stopped using it. And cell phones don't cause cancer (directly, at least - they may still be a contributor) because their radiation levels are too low. What is common about these two things is that scientific knowledge, in both cases, influenced policy and action is such a way as to prevent further disaster. DDT stopped being used, and cell phone companies have been very wary of radiation levels from their units.

 

Just an interesting thing.

[Balta1701]

These are two interesting parallels, but I need to point out a couple things. One, DDT didn't kill off as many things as it could have because we stopped using it. And cell phones don't cause cancer (directly, at least - they may still be a contributor) because their radiation levels are too low. What is common about these two things is that scientific knowledge, in both cases, influenced policy and action is such a way as to prevent further disaster. DDT stopped being used, and cell phone companies have been very wary of radiation levels from their units.

 

Just an interesting thing.

He does have a point on some level...and that's one of the things that makes science actually worth doing, is that sometimes not everyone is going to agree on some theory, and therefore, it can be tough to make decisions based on some theories. And it can be even tougher to judge when one side of an issue has won the day, especially if you are not well versed on a topic. Especially if there is some well-funded political organization dedicated to convincing people that the other side is correct regardless of the science.

 

But let's deal with the specific cases he cites, Global Warming and Evolution. First and foremost, let me say this in response to this claim:

BUT, scientists of today rely on 100 years worth of data (a good chunk of which is probably unreliable) to inductively reason that WE are the cause of some impending global warming disaster, never mind the fact that the Earth has been both ice and fire many times over.

Yes, it is true the earth has been very hot and very cold many times in the past. And almost regardless of what we put into the atmosphere, the Earth, and Life itself on Earth, and mankind, are going to survive. But there's one thing you're missing that is of some importance...humankind has not always been on earth. Humankind has not always set down roots in places, and developed societies based around the climate in certain areas. This is the new feature, and it's the real concern in global warming. Should you be concerned that we're going to turn the earth into Venus? Pretty darn doubtful. Should you be concerned that maybe the water resources that feed a city of 10 million might alter their paths, or dry up because of this phenomenon? Or that currently arable land will dry up, causing food shortages in some regions? Absolutely. Just because the Earth will survive doesn't mean that the costs of doing nothing won't be judged to be a disaster by many people.

 

But now, on to the big picture. Here we see, overall, in terms of both global warming and evolution, the classic argument that we are always ignorant, that no matter how much we learn, we can never know anything. No matter how many lines of evidence we have that organisms evolve by natural selection, or that increasing CO2 in the atmosphere can change the climate, we can never know enough. This argument is a bit of an odd one, because it is applied so unfairly. It is only really applied when people have some other reason to doubt every bit of the science on a topic with which they disagree. We only have a few thousand years of evidence for how gravity works, so why should we conclude that Isaac Newton's law is an accurate represntation? We have only a few decades of evidence for the quantum behavior of the electron, so why should we conclude that computers work?

 

Here is the big picture...if you want to actually learn about something, then learn about it. Don't tell us that we can't learn about something or that we're guaranteed to be wrong unless you actually know enough about something and care enough to learn the details. The theory of evolution is not just based on "Some bones". The theory of evolution by natural selection is based on a century worth of data collected in the field and in laboratories that tells literally hundreds of thousands of different stories, from the formation of the different kingdoms of life to the evolution of specific lineages, to the decline and extinction of those lineages, and so on, all the way up to the present. You can go into the laboratory and see evolution happening. Hell, by dumping tons of antibiotics on the world, we're doing our own natural selection experiments. You can trace the evolution of genes back through time to the species where they first appeared. You can trace species from the era they appeared, through their rise, and through their fall. Do we have every single answer? No. But we have a lot more than just "Some bones". We have a fully funtioning theory that is testable, makes predictions, and simply has not been falsified no matter where anyone has looked.

 

Global warming is roughly the same way. Yes, a half a century ago, our understanding of the connections in the system were not as good as they are now. But that doesn't mean we don't have it right now. Now what we have is a working model which makes predictions which come true. Based on physics, we can understand that CO2 absorbs energy in a specific light wavelength, and as you increase the CO2 content of the atmosphere, you absorb more energy, forcing the planet to increase its temperature in order to radiate at a different frequency. We can tell from geology that in the past, both millions of years ago and thousands of years ago, large temperature spikes have been concurrent with large increases in atmospheric CO2. We can tell from chemistry that the CO2 content has gone up, not just from measuring the CO2 in the atmosphere but by looking at a huge number of other proxies, like the acidity of the ocean and so forth. We can tell from satellites that the oceans themselves are expanding as sea level rises, and this would be predicted if the oceans were warming (thermal expansion). And using computers to take into account more variables than we can in our heads, we can even estimate how important the different forcings are, and what their results are.

 

So, you are right in 1 sense...an answer derived through science cannot just be taken as concrete. But that is in fact the beauty of science, not its flaw. If you want to overturn something in science, you need evidence. And you need evidence equal to what you're trying to overthrow. In terms of evolution, there simply isn't any. It tells a story. It's not the story of every single cell ever to exist on this planet, but it is a shockingly complete story. Unbelievably complete. Vastly more than just "some bones". In terms of anthropogenic global warming, the evidence that says it isn't happening is almost non-existent at this point, the only debate is to the intensity of it and the results. So you ask why scientists claim these are unquestionable facts? Well, the answer to that is simple...scientists have learned enough to make that judgement on their own, and are telling you that from their position.

 

If you want to say that none of it is happening and say that someone should not say that evolution by natural selection or anthropogenic global warming is not true, then actually learn what case is being made, take a look at the evidence, and judge for yourself. But if you're willing to throw the evidence for either of those out the window as flimsy, having spent a significant amount of time learning about both of them, I will say from my position that I believe you are completely wrong if you want to question either of those theories. And if I had the time and didn't have to keep entering data into this PC at some point, I could spend hours giving you well-researched, tested facts that would show why.

 

But all I will ask is this...don't just make the argument that we are forever ignorant without giving me a reason to believe that we are ignorant in this case. Has science said things incorrectly in the past? Of course. Will it in the future? Of course. But you can not simply say that "Science has made mistakes on issue x or issue y in the past, so we should never trust scientists on issue z" without either giving me a reason to suspect that we are wrong on issue z. That is not a logical progression, and it is a mistake to pretend it is so.

 

It is for that same reason that some will take folks who say that the evidence for evolution by natural selection or anthropogenic global warming and say that they should stop using their computers because they can't guarantee that the electricity will keep working the way it always has, because that sort of argument that we are always ignorant can and should be applied in any and every aspect of science. You just have more experience with certain accomplishments of science, so you have a habit of not applying it to those theories with which you actually have familiarity. You don't, for example, put furniture on your ceiling just in case gravity stops working, because you have extensive experience with gravity, so you don't think to say "Well science says gravity works this way, but science has been wrong before, so I should be careful." However, that is another expression of the exact same logic which you are trying to apply. But with Gravity, you know enough not to doubt how it works, because you have expereinced it yourself and you know the evidence.

[Jenksismyhero]

But there's one thing you're missing that is of some importance...humankind has not always been on earth. Humankind has not always set down roots in places, and developed societies based around the climate in certain areas. This is the new feature, and it's the real concern in global warming. Should you be concerned that we're going to turn the earth into Venus? Pretty darn doubtful. Should you be concerned that maybe the water resources that feed a city of 10 million might alter their paths, or dry up because of this phenomenon? Or that currently arable land will dry up, causing food shortages in some regions? Absolutely. Just because the Earth will survive doesn't mean that the costs of doing nothing won't be judged to be a disaster by many people.

 

But that's not global warming so much as wasting or abusing natural resources. I think that's entirely different than the message Al "i'm serial you guys" Gore wants to make: i.e. that if we don't stop driving SUV's the entire coast line of the US will be Katrina 2 (damn George W). My using my Ford SUV isn't going to create a new hurricane Katrina as much as he'd like to think. Me using that car has an effect, no doubt about that, but so does an increase in flatulence from grazing cows. I'm not saying that humans shouldn't alter their practices and be more "environmentally friendly," but to say that we're ruining the earth and will soon kill ourselves is ludacris.

 

 

But now, on to the big picture. Here we see, overall, in terms of both global warming and evolution, the classic argument that we are always ignorant, that no matter how much we learn, we can never know anything.

 

 

That's not my argument. My argument is stop assuming theories are fact. Just because one theory has more evidence than another doesn't a) dispute the first and B) make the second pure fact.

 

Here is the big picture...if you want to actually learn about something, then learn about it. Don't tell us that we can't learn about something or that we're guaranteed to be wrong unless you actually know enough about something and care enough to learn the details.

 

I complete agree with this point.

 

 

The theory of evolution is not just based on "Some bones". The theory of evolution by natural selection is based on a century worth of data collected in the field and in laboratories that tells literally hundreds of thousands of different stories, from the formation of the different kingdoms of life to the evolution of specific lineages, to the decline and extinction of those lineages, and so on, all the way up to the present. You can go into the laboratory and see evolution happening.

 

But you can't tell me WHY it's happening. How come a lady bug has PERFECTLY straight lines and circles on it's body. According to the natural selection theory (which many have begin to question btw), there must have been thousands and thousands of lady bugs with all different shapes and sizes of patterns. The one that lives today just happened to outlast the rest. Nevermind WHERE the patterns came from, but HOW does one generation of lady bug simply create new patterns on it's back. It's different from a physical evolution, where physical activity changes bone structures in one generation that are slowly evolved through that species lineage and genes. Until they answer that question it's still a THEORY, regardless of the proof that we see SOME changes over time.

 

 

Global warming is roughly the same way. Yes, a half a century ago, our understanding of the connections in the system were not as good as they are now. But that doesn't mean we don't have it right now. Now what we have is a working model which makes predictions which come true. Based on physics, we can understand that CO2 absorbs energy in a specific light wavelength, and as you increase the CO2 content of the atmosphere, you absorb more energy, forcing the planet to increase its temperature in order to radiate at a different frequency. We can tell from geology that in the past, both millions of years ago and thousands of years ago, large temperature spikes have been concurrent with large increases in atmospheric CO2. We can tell from chemistry that the CO2 content has gone up, not just from measuring the CO2 in the atmosphere but by looking at a huge number of other proxies, like the acidity of the ocean and so forth. We can tell from satellites that the oceans themselves are expanding as sea level rises, and this would be predicted if the oceans were warming (thermal expansion). And using computers to take into account more variables than we can in our heads, we can even estimate how important the different forcings are, and what their results are.

 

You know more about the science of this than I do, so I'll defer to your expertise. However, I guess I need more in the way of proof that our contribution to the CO2 issues weren't already happening naturally. Again, not saying we aren't doing ANYTHING, but when glaciers have melted numerous times in the past, it's hard for me to jump at a theory that explains the reason it's happening THIS time is our fault. We just don't have enough data yet to judge. And even if 150 years down the line the argument remains, we STILL might not know because the Earth could just be in a hotter period for currently unknown reasons. It's the best we've come up with so far, yeah, but that doesn't mean morons like Al Gore should be "teaching" the public this information as if it's fact.

 

You don't, for example, put furniture on your ceiling just in case gravity stops working, because you have extensive experience with gravity, so you don't think to say "Well science says gravity works this way, but science has been wrong before, so I should be careful." However, that is another expression of the exact same logic which you are trying to apply. But with Gravity, you know enough not to doubt how it works, because you have expereinced it yourself and you know the evidence.

 

A law of physics and theories about how we came to be and our effect on the impending disaster of a planet are a little different. And again, i'm not saying that because science has failed in the past never trust science. I'm saying it's wrong for people to assume that a theory, even with "evidence," that still has so many unanswered questions shouldn't be unquestionable fact, anymore so than an old book with a man and his white beard.

[Balta1701]

But you can't tell me WHY it's happening. How come a lady bug has PERFECTLY straight lines and circles on it's body. According to the natural selection theory (which many have begin to question btw), there must have been thousands and thousands of lady bugs with all different shapes and sizes of patterns. The one that lives today just happened to outlast the rest. Nevermind WHERE the patterns came from, but HOW does one generation of lady bug simply create new patterns on it's back. It's different from a physical evolution, where physical activity changes bone structures in one generation that are slowly evolved through that species lineage and genes. Until they answer that question it's still a THEORY, regardless of the proof that we see SOME changes over time.

Random mutations between generations as cells divide and DNA strands are recombined. This is observed constantly in biology. Many mutations will wind up being detrimental, but many others wind up either having no effect at the current time or wind up being beneficial in other ways. This is seen constantly, even in the lab. These mutations occur, their frequency in the population will then increase if they provide a selective advantage or they will be filtered out if they do not do so. That is the key part of the modern synthesis of Evolution. And of the "Many" who have begun to question it, virtually none are biologists or geologists actually dealing with that theory on an everyday basis.

 

Beyond that, all you do is repeat the argument that we are always ignorant, or should always be assumed to be ignorant, in other forms, because you judge the evidence to be incomplete without a full understanding of the evidence. You say that having more evidence about one theory does not make it fact, which is correct, but then you refuse to acknowledge the evidence that does exist if it points in a direction you don't like. I think I've said my peace in this thread.

Edited August 16, 2006 by Balta1701

[CrimsonWeltall]

How come a lady bug has PERFECTLY straight lines and circles on it's body.

 

?

 

They don't. Do a google image search. The spot patterns are pretty random.

 

According to the natural selection theory (which many have begin to question btw), there must have been thousands and thousands of lady bugs with all different shapes and sizes of patterns. The one that lives today just happened to outlast the rest.

 

There still are thousands and thousands of lady bugs with different sizes and shapes of patterns.

 

It's different from a physical evolution, where physical activity changes bone structures in one generation that are slowly evolved through that species lineage and genes.

 

I'm not sure what this means.

 

Until they answer that question it's still a THEORY

 

Nothing goes higher than theory. A 'fact' is basically just a theory that all reasonable and informed people would accept.

[maggliopipe]

It's different from a physical evolution, where physical activity changes bone structures in one generation that are slowly evolved through that species lineage and genes.

 

Dude you should totally publish this, it's nothing short of Nature worthy.

 

I'm pretty sure this must be what happened with the lobster-claws-for-hands family. It all started as a practical joke by an ancestor.

[rangercal]

f*** science!

[vandy125]

I am curious about what people think of the distinction between macro-evolution and micro-evolution. An example of micro-evolution would be moths changing their wing color to live in a darkening forest, or the birds on an island changing their beak size based upon different environmental influences. An example of macro-evolution would be the jump from ape to man. Do you make that distinction or not?

 

As for Global Warming, it is interesting to note that when we started releasing CO2 into the atmosphere by burning up oil, etc that had been undisturbed for millions of years that it corresponds with an increase in temperature. I do not know if the increase in temperature is caused by what we are doing (I suspect it might), or if the earth is just naturally doing its thing. But, we should note that we are seeing the increase in temperature at the same time that we started adding more CO2 into the atmosphere.

[Balta1701]

I am curious about what people think of the distinction between macro-evolution and micro-evolution. An example of micro-evolution would be moths changing their wing color to live in a darkening forest, or the birds on an island changing their beak size based upon different environmental influences. An example of macro-evolution would be the jump from ape to man. Do you make that distinction or not?

Personally, I think there is a distinction, but the distinction is unimportant. The entire difference between them is a result of the size of the population you're allowing to evolve.

 

The most strict definition of evolution would be any change in the frequency of alleles in a population. This can happen through random chance even (i.e. you go from 51% of a population being blonde to 52% just through the number of children conceived in a generation or something like that) or it can happen due to selective pressures.

 

What you refer to as "Micro-evolution" would be anything that impacts such a large group of individuals so as to not really produce 2 distinct populations. What you'd define as "Macro-evolution" is something that actually leads to division and reproductive isolation between 2 groups of what was formerly a single species, where one group adopts a characteristic not present in the other group.

 

The reality of this is, it's all a matter of population size and isolation. If you have a small population of a species with enough diversity to be able to keep itself going, it is vastly more likely that mutations which arise within this group will be adopted within a short amount of time. However, if you have a large population, it is going to take much longer and much larger selective pressures for a new trait to be adopted throughout the population. In one case, the isolation of a smaller group will encourage more rapid "Macro-evolution", while in the other case, the breeding of a larger group will lead to the adoption of new traits in what you'd call "Micro-evolution".

 

I for one see it as a distinction without a difference. The only real dividing line is one of population size. The larger a population is, the more likely its genetic makeup is to stay steady, while the smaller a population is, the more likely it is that traits can be adopted throughout a group.

[vandy125]

The most strict definition of evolution would be any change in the frequency of alleles in a population. This can happen through random chance even (i.e. you go from 51% of a population being blonde to 52% just through the number of children conceived in a generation or something like that) or it can happen due to selective pressures.

 

Shouldn't that definition also include a gain of information? For example, to evolve from a single-celled organism to a multi-celled organism would require a gain in information.

 

I agree about the distinction between micro and macro evolution, and I know that we have several examples of micro evolution taking place, but have you heard of any good, solid examples of macro-evolution being observed? Or, is that something that cannot be observed today because of different things like it taking too long to occur?

[Balta1701]

Shouldn't that definition also include a gain of information? For example, to evolve from a single-celled organism to a multi-celled organism would require a gain in information.

A gain in information, if we want to call it that (I'm not a fan of that term since there's no real great definition for the total amount of information contained within a DNA Unit) would also fit...anything which changes the ratio of alleles in a population would fit that definition, including the appearance of new mutations.

 

I agree about the distinction between micro and macro evolution, and I know that we have several examples of micro evolution taking place, but have you heard of any good, solid examples of macro-evolution being observed? Or, is that something that cannot be observed today because of different things like it taking too long to occur?

Well, yeah, the big problem you run into in providing a concrete example is time, in that significant changes in species, to the point where 2 formerly joined populations will be unable to breed if they rejoin each other, simply does take quite a few generations. It has been observed in plants, however, with the classic example being wheat, where a series of mutations led to the development of the modern-day grain from older plants. It has also been observed in the laboratory...just one example, using the classic fruit flies that a lot of scientists play with because they do reproduce quickly...Rice and Salt (1988) placed originally genetically matching groups of fruit flies under different conditions of food, water, light, and so forth, and after several generations, they brought the groups back together, and found that they were different enough that the two groups did not interbreed.

 

Here and here are some short lists of examples where scientists have in fact observed speciation, or what you might call macro-evolution, taking place.

[vandy125]

A gain in information, if we want to call it that (I'm not a fan of that term since there's no real great definition for the total amount of information contained within a DNA Unit) would also fit...anything which changes the ratio of alleles in a population would fit that definition, including the appearance of new mutations.

Well, yeah, the big problem you run into in providing a concrete example is time, in that significant changes in species, to the point where 2 formerly joined populations will be unable to breed if they rejoin each other, simply does take quite a few generations. It has been observed in plants, however, with the classic example being wheat, where a series of mutations led to the development of the modern-day grain from older plants. It has also been observed in the laboratory...just one example, using the classic fruit flies that a lot of scientists play with because they do reproduce quickly...Rice and Salt (1988) placed originally genetically matching groups of fruit flies under different conditions of food, water, light, and so forth, and after several generations, they brought the groups back together, and found that they were different enough that the two groups did not interbreed.

 

Here and here are some short lists of examples where scientists have in fact observed speciation, or what you might call macro-evolution, taking place.

 

To me, those do not sound like examples of macroevolution. In those examples that I read and looked at, it seemed to me that nothing fundamental has changed about the fruitflys, the different plants, etc.

 

Take the fruit flies as an example. The whole group had the ability to survive the different conditions that they put them in, but as time progressed, the one's that could better survive the different environments became more prevalent. This is natural selection, and to me it seems like there was no gain of information or abilities. Natural selection is different from evolution. In fact, it seems like they lost abilities because they were no longer able to interbreed with other types of fruit flies.

 

What I am looking for is some sort of useful ability gained, something added to them, not already existing abilities within a species. If I read correctly about some of the cross-hybridization, (I am looking at the 5.1.1.4 Raphanobrassica section as an example), it appears that they have even gotten plants to trade some of their abilites, but again, I do not see any gains in useful abilities.

 

Am I missing something with all of this? If I understand alleles correctly, I would not think the change in a ratio of these is what I am looking for (one gene becoming more dominant if I am correct?). To me those are abilities that an organism already has. I would be looking more towards the mutations that add new genes that are useful for the organism's survival.

[Balta1701]

Am I missing something with all of this? If I understand alleles correctly, I would not think the change in a ratio of these is what I am looking for (one gene becoming more dominant if I am correct?). To me those are abilities that an organism already has. I would be looking more towards the mutations that add new genes that are useful for the organism's survival.

Well, again, just from looking at the genetics, you're not totally missing something, because the issue really becomes the rate at which these things happen. When you're dealing with moderately large populations, as you are with many species out in the wilderness, you just don't have small groups very often where they are isolated long enough for new traits to both emerge and become dominant. Especially now that humanity is there and is moving much more rapidly than any other species ever really has.

 

If you let me go back to the fossil record, there are absolutely tons of examples of new traits appearing over time. Bone structures changing, shells changing, you name it. We can do similar things with biological tools to some extent, and by isolating specific genes that are related to specific changes in species and to reasonable margins of error figure out when those genes first appeared. This is done all of the time in my building...they have a bunch of bacteria they like to play with to do so.

 

Here's a prime example from plants. Let's go right back to wheat, because it is a good example of both. Wheat is not just how we see it today due to the replication of chromosomes, but after these replications, wheat has been acted on by various other mutations and selective pressures to bring it where it is today. Here is a recent paper (not sure if you can actually get to that abstract, I can) that discusses how the wheat genes weren't just replciated, but after they were replicated, due to random mutations, some of the genes shut off, others began to work in different ways, so right now, the chromosomes that were replicated in those events are no longer identical. That, IMO, can only be judged as a gain in information, by any standard. Here's an excerpt in case you can't see that.

 

Recent studies have shown that allopolyploidy accelerates genome evolution in wheat in two ways: (1) allopolyploidization triggers rapid genome changes (revolutionary changes) through the instantaneous generation of a variety of cardinal genetic and epigenetic alterations, and (2) the allopolyploid condition facilitates sporadic genomic changes during the life of the species (evolutionary changes) that are not attainable at the diploid level. The revolutionary changes comprise (1) non-random elimination of coding and non-coding DNA sequences, (2) epigenetic changes such as DNA methylation of coding and non-coding DNA leading, among others, to gene silencing, (3) activation of genes and retroelements which in turn alters the expression of adjacent genes.

Basically, what it is giving there is a summary of the things happening other than the allopolyploidy event, shutting off of genes on certain chromosomes or changes in genes on other spots. This happens more rapidly because of the shear number of new genes that mutation gets to play with. So in other words, you start off with x number of genes, you triple that number, but they start off identical, but then they rapidly diverge, so that you wind up with significant numbers of new non-matching genes between the chromosomes.

 

There are other examples, but again we're limited in what we can really conceive of because of the time span. Another prime example is the development of resistence to certain drugs in viruses and bacteria. You start off with an antibiotic which actually does cure a disease, but eventually a random mutation arises in some of those bugs that allows them to resist the antibiotic. Suddenly, when the antibiotic is used, it kills off all the non-resistant bugs, allowing the bugs with the new mutation to grow more rapidly.

[vandy125]

If you let me go back to the fossil record, there are absolutely tons of examples of new traits appearing over time. Bone structures changing, shells changing, you name it. We can do similar things with biological tools to some extent, and by isolating specific genes that are related to specific changes in species and to reasonable margins of error figure out when those genes first appeared. This is done all of the time in my building...they have a bunch of bacteria they like to play with to do so.

 

I had always been under the impression that the fossil record was not very conclusive as far as showing macroevolution taking place. If it was, then there probably would not be a debate between a graduated evolution occuring (small steps) vs the punctualistic evolution occurring (big steps all at once). From what I have understood, we do not yet have enough evidence to declare either way, and I am not sure what type of evidence there would be to say that it was graduated.

 

There is also the issue of the Cambrian explosion of fossils. I have heard that just about every species now living can trace itself back to that time. Why is it that so much of that happened in one time period? Why is there not a steady development of the fossil record before and through that time?

 

Here's a prime example from plants. Let's go right back to wheat, because it is a good example of both. Wheat is not just how we see it today due to the replication of chromosomes, but after these replications, wheat has been acted on by various other mutations and selective pressures to bring it where it is today. Here is a recent paper (not sure if you can actually get to that abstract, I can) that discusses how the wheat genes weren't just replciated, but after they were replicated, due to random mutations, some of the genes shut off, others began to work in different ways, so right now, the chromosomes that were replicated in those events are no longer identical. That, IMO, can only be judged as a gain in information, by any standard. Here's an excerpt in case you can't see that.

...

There are other examples, but again we're limited in what we can really conceive of because of the time span. Another prime example is the development of resistence to certain drugs in viruses and bacteria. You start off with an antibiotic which actually does cure a disease, but eventually a random mutation arises in some of those bugs that allows them to resist the antibiotic. Suddenly, when the antibiotic is used, it kills off all the non-resistant bugs, allowing the bugs with the new mutation to grow more rapidly.

 

There again, I am not sure that I see this information gain. It seems more like old information is being replaced with new information. That is a net effect of 0. You say that certain genes shut off. So, they are losing information when that happens, but the new mutations take over which pretty much replaces the old genes that got shut off. The wheat is still wheat, and the virus is still a virus.

 

I guess what it comes down to is that, like you said, the rate at which these things can supposedly happen is far too slow for us to be able to see new abilities form. IMO, the fossils do not yet show us this happening in a manner that we can say it was gradual. We see points A and B in what we think the path is, but we do not yet have good evidence as to how something could move from point A to point B due to the incredibly slow rate that they occur.

[CrimsonWeltall]

I had always been under the impression that the fossil record was not very conclusive as far as showing macroevolution taking place. If it was, then there probably would not be a debate between a graduated evolution occuring (small steps) vs the punctualistic evolution occurring (big steps all at once).

 

If you saw a guy's bank account go from $0 in 1996 to $20,000 in 1997 to $40,000 in 1998, some people might think the guy worked a steady job for two years and some might think that he won a small lottery twice and didn't do jack squat the rest of the time. That debate wouldn't imply doubt about whether or not some process of money-making did occur.

 

There is also the issue of the Cambrian explosion of fossils. I have heard that just about every species now living can trace itself back to that time. Why is it that so much of that happened in one time period?

 

You heard incorrectly. The special thing about the Cambrian period is that man of the animal phyla make their first appearance there. If you look at them, you'll notice a lot of them are things like Worms, Worms with Legs, Worms That Are Longer Than Those Other Worms, and a bunch of microscopic organisms.

 

Plants, mammals, reptiles, birds, most fish, insects, etc (the things we would consider to be most species now living) came well after the Cambrian.

 

Why is so much found there? Maybe there were some major evolutionary changes then. Also, the organisms before then are pretty much soft-bodied things that are hard to find fossils for anyway.

 

 

There again, I am not sure that I see this information gain. It seems more like old information is being replaced with new information.

 

First, all wheat have ABCD. Mutation leads to a D replaced by another C. Now, some wheat exist with ABCD and some have ABCC. Even if all thw ABCC wheat were super sexy and all the ABCD wheat couldn't get laid and pass on their genes, the ABCC wheat is still 'new'.

 

The wheat is still wheat, and the virus is still a virus.

 

Where do you draw the line? Is corn still maize? Is maize still teosinte? Is corn still just teosinte then? Are homo sapiens still just homo erectus? Is a chihuahua a great dane?

[Balta1701]

I had always been under the impression that the fossil record was not very conclusive as far as showing macroevolution taking place. If it was, then there probably would not be a debate between a graduated evolution occuring (small steps) vs the punctualistic evolution occurring (big steps all at once). From what I have understood, we do not yet have enough evidence to declare either way, and I am not sure what type of evidence there would be to say that it was graduated.

Here's the interesting thing though, if I'm talking about evolution bringing significant changes to a population, to the point of the splitting of 1 species into 2, punctuated events are exactly what I'd expect to see in the fossil record. As we've been discussing, the best way for significant changes to happen, and for mutations to be able to pile up, is for reproductive isolation to happen within a small group. In a large group, i.e. a whole population of a species, the odds of a mutation, however beneficial, becoming dominant are very low just because of inertia...it's hard to have every single member of a species of millions adopt a trait that only has a limited start. However, if I have a population of a few hundreds, because a group has been cut off from the main body of a population, it is far more likely that innovative new traits will be adopted by the whole group. So the most likely thing we're going to see in the fossil record is going to be fairly sudden appearances of moderately changed species, because the odds of us finding the specific group where the mutation arose is very low, but as the new group expands to more areas due to its new selective advantage from the accumulated mutations, it will become more likely that it will be preserved.

 

There is also the issue of the Cambrian explosion of fossils. I have heard that just about every species now living can trace itself back to that time. Why is it that so much of that happened in one time period? Why is there not a steady development of the fossil record before and through that time?

Several points on the Cambrian. The most important change that happened at the Cambrian was only 1 evolutionary development: the development of "Hard parts". In other words, shells, or skeletal material of some sort. So the big difference from the Precambrian to the Cambrian was the sudden increase in the likelihood of preserving fossil material...since suddenly there were hard parts to preserve.

 

Contrary to the suggestion of the previous poster, in fact, all of the modern phyla did not appear at the beginning of the Cambrian. In fact, we have evidence in the fossil record of most of the phyla that are talked about by creationist/ID folks as appearing suddenly at the beginning of the Cambrian actually appeared gradually, during the last few tens of millions of years of the Precambrian (we call that period the Ediacaran) and during the first 20 million years of the Cambrian itself.

 

The big, interesting thing of the Cambrian is more due to the Burgess Shale fauna than anything else. This is one particular unit from Canada with a wide variety of different, spiny creatures from it. But the other noteworthy thing about it is that most of those odd shapes never really amounted to anything, and most of them fall within a very limited number of phyla. Basically, there was a decent amount of radiation within a few small groups that had developed the ability to use hard parts, and they left some really funny shapes in that deposit.

 

For more on the Cambrian Explosion itself, i'll fire to one random paper by a prof at Kansas State, who can give you a slightly better explanation than me.

Many metazoan groups appeared before the Cambrian, including representatives of several living phyla. Furthermore, the many small scale, plate, and spine-bearing organisms of the earliest Cambrian, while sharing characteristics with several living phyla, are also similar enough to each other to be classified by some workers into a single phylum.33 Even when the metazoan fossil record for the entire Cambrian is considered, the morphological disparity cannot be equated with that of living organisms, unless the subsequent appearance of all vertebrate and insect life be ignored. In addition, many living phyla, including most worm phyla, are unknown from the fossil record until well into the Phanerozoic.34 Thus, to claim the near simultaneous appearance of virtually all living phlya in the Cambrian is not an objective statement of the fossil evidence but a highly speculative, and I believe unsupported, interpretation of it35

 

Finally, there is a question of whether the rapid diversification of metazoans in the Late Precambrian and Early Cambrian reflects an equally rapid increase in complexity. An interesting study by Valentine and others uses the number of cell types as a useful measure of morphological complexity. They plot the estimated times of origin of major body plans against their cell type numbers. The resulting plot shows that the upper bound of complexity has increased steadily and nearly linearly from the origin of the metazoa to the present. Furthermore, they conclude that "...the metazoan `explosion' near the Precambrian/Cambrian transition was not associated with any important increase in complexity of body plans...36 This suggests that the appearance of new higher taxa in the Cambrian did not involve the sudden appearance of major new levels of complexity.

 

There again, I am not sure that I see this information gain. It seems more like old information is being replaced with new information. That is a net effect of 0. You say that certain genes shut off. So, they are losing information when that happens, but the new mutations take over which pretty much replaces the old genes that got shut off. The wheat is still wheat, and the virus is still a virus.

Ok, what you should think about it as is this. 3 genes, ABC. Double each of those genes. Now you have AABBCC. So you can claim if you wish that no information has been generated there, I don't believe that because a duplication is an increase in information to my eyes, but now, allow evolution to change any of those genes. Suddenly, we have AABBC1C2. Now we have 4 genes in 6 slots, whereas we started with only 3. We have gained information, because the original C gene is still there (and hence we haven't lost anything), but there is also a new C gene which functions in a different way.

 

I guess what it comes down to is that, like you said, the rate at which these things can supposedly happen is far too slow for us to be able to see new abilities form. IMO, the fossils do not yet show us this happening in a manner that we can say it was gradual. We see points A and B in what we think the path is, but we do not yet have good evidence as to how something could move from point A to point B due to the incredibly slow rate that they occur.

At this point, since it seems I am unable to convince you, I'm going to turn to a much more detailed source on the issue. If you want as much data as humanly possible on this topic, I'd suggest you peruse this page. "29+ Evidences for Macroevolution: The Scientific Case for Common Descent"

Edited August 19, 2006 by Balta1701

[CrimsonWeltall]

Contrary to the suggestion of the previous poster, in fact, all of the modern phyla did not appear at the beginning of the Cambrian.

 

I didn't say all of the modern phyla appeared. I said "mad of the animal phyla make their first appearance there". "Mad" was supposed to be "many".

[Balta1701]

I didn't say all of the modern phyla appeared. I said "mad of the animal phyla make their first appearance there". "Mad" was supposed to be "many".

True, i was slightly off, but it's still worth noting that the appearance of "Many of the animal phyla", which is one of the things people talk about happening in the Cambrian, actually happened over something like 50-100 million years, from the latter Ediacaran to basically the whole Cambrian.