Evolution is a Belief System

[David Koot]

Evolution is a belief system based on insupportable assumptions. "Evolution" as used herein, is Darwinian, long-age evolution.

Any thoughts?

[bevin]

Yes.

I think you are trolling, and have no intention of seriously discussing the issue.

/Bevin

[David Koot]

Trolling? Very well, tell me, in your opinion, does evolution rely on any assumptions? If so, then which assumptions? Or, do you deny that evolution relies on any assumptions?

[Bravus]

Yes, evolution relies on the naturalistic assumption that everything we see must be explained in terms of the operation of natural laws. That can in turn mean a complete disbelief in the existence of miracles and supernatural acts, but many more modest evolutionists would simply say that, if supernatural acts occur, they are outside the ability of science to explain, by definition.

So yes, evolution can be considered to be a belief system, but whether the involved assumptions are 'insupportable' is a value judgement, and your judgement call will depend upon... your own set of assumptions.

[David Koot]

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Bravus said:

Yes, evolution relies on the naturalistic assumption that everything we see must be explained in terms of the operation of natural laws.

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Very well, that is one assumption. Surely there are others? What assumptions are required in order to believe in the 'Cambrian Explosion,' for example? Could you list them here?

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So yes, evolution can be considered to be a belief system, but whether the involved assumptions are 'insupportable' is a value judgement, and your judgement call will depend upon... your own set of assumptions.

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Perhaps. Or, there may be more objective ways to assess them. We might start by listing the assumptions. You have mentioned one. How about others?

[Bravus]

I'm not sure there are any others that are fundamental. Everything else is a matter of observation. do we see mutation? Yes. Do we see natural selection? Yes. Do we see the 'Cambrian Explosion' in the fossil record? Yes. I'd be happy to list other assmuptions if I knew of any, but as far as I can see it basically all arises from that fundamental assumption, and from looking at the world we see around us through it.

[David Koot]

Okay . . . The data exist. We observe the data. We interpret the data. Error may occur in the process of observing the data. More importantly, error may occur in interpreting the data. It seems to me that "interpreting" is where the process really becomes subjective.

It is one thing to observe and interpret data which we can observe and test at the present time. An example of that is biological evolution. Natural selection, mutation, genetic drift, may be observed and documented as they occur at present.

However, to go beyond what may be presently observed and verified, and to speculate that because of natural selection, genetic drift, etc., a fish may become a cow--THAT is, indeed, speculation. That has not been observed. Postulating such an occurrence would require a number of assumptions. So, what are the assumptions required for macroevolution?

[Bravus]

First, I should state that although I'm a scientist and science educator, biology is definitely not my field, so whatever I say should be taken in light of that.

As I understand it, the assumption is 'macroevolution = microevolution plus enough time'. Perhaps that's another assumption, although I'd argue that it still arises from the basic 'we see many species now, and we assume they were not divinely created, so therefore they must have arisen through the extension of natural processes that we observe now occurring on vast time scales'.

Bevin has enumerated the various forms of evidence that are relevant in the past, so I won't repeat that, but it's not as simple as just the biological evidence, since there is related paleontological evidence. And of course, a fish doesn't 'turn into' a cow. A fish turns into a mudskipper turns into an amphibian turns into a small mammal... and many, many more tiny steps, each an adaptation to a particular environment. A fish is superbly adapted to the ocean, a cow (and remember our domestic cows have millenia of selective breeding in their make-up too) is superbly adapted for a farmer's field and a milking shed.

(reminder: I'm not an (atheistic) evolutionist, I'm trying to state their case fairly and destrawmanify the argument)

[bevin]

Yes, I deny that evolution rests on assumptions.

I feel pain, and I don't like it.

I sense my environment.

I develop ways of predicting pain based on my senses.

I see that they work by seeing if they correctly predict when I will feel pain before I do.

I develop ways of manipulating the environment.

I test that they work by seeing if the pain decreases.

I use these same methods of predicting other aspects of my environment.

I use them to predict what I will find if I look under this rock.

If the prediction is wrong, I work on improving either the inputs or the algorithm.

At no point do I need to assume anything. If I get a bad prediction I slowly back up - did I get the result right?did I do the modelling right? did I get the inputs right? Eventually I decide the model itself was wrong and I correct it - and use the corrected model to check my previous work.

I never assume I got anything right - I am prepared to be wrong at all levels. There are no assumptions.

Heck - I even know that it is possible that my sense of pain is wrong and my memory is wrong.

Pragmatically though, I like avoiding pain.

The repeated application of 'observe, predict, check, fix model' is what has lead science to evolution. There are no assumptions required.

/Bevin

[David Koot]

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Bravus said:

As I understand it, the assumption is 'macroevolution = microevolution plus enough time'. Perhaps that's another assumption, although I'd argue that it still arises from the basic 'we see many species now, and we assume they were not divinely created, so therefore they must have arisen through the extension of natural processes that we observe now occurring on vast time scales'.

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Ahh, the sweet voice of reason. Indeed, it could not be otherwise than you have stated. The nature of our physical existence imposes severe limitations upon us. We can only occupy one point in spacetime at any given moment. At that point in spacetime, all we can do is have perceptions. We necessarily make assumptions, even on the level of what we can actually see, hear, touch, etc. Once we go back in time, we must make another level of assumptions.

It may be reasonable to assume, for example, that biological evolution to the extent we have actually observed it at present--cross-breeding, genetic drift, mutation, natural selection--occurred in the past. Although, even that assumption requires other assumptions--but, probably not unreasonable assumptions.

HOWEVER, to assume macroevolution requires still another level of assumptions. Noone to my awareness, has actually observed macroevolution. Please correct me if I am wrong, professor. Alright, I have no problem with the observations in regard to genera (I prefer 'genii' grammatically, but oh well) as described in the article which I posted a link to). But, I am not talking about cross-breeding here, or of selective breeding, etc. Let's talk about naturally-occurring GIANT steps.

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And of course, a fish doesn't 'turn into' a cow. A fish turns into a mudskipper turns into an amphibian turns into a small mammal... and many, many more tiny steps, each an adaptation to a particular environment.

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Very well . . . what is the biggest step in macroevolution which has actually been observed to occur, that you are aware of, from the literature? Have any instances of evolution across kingdom lines been observed and verified? How about phylum lines? Or, any other level of taxa?

David Koot

[Bravus]

As I said, I'm no biologist, so I don't know of specific examples. I'll google a bit, but anyone else who can name examples is welcome to. But I think it's a time-scale issue: the size of changes that would be required to move from species to species are too great to have occurred in the number of generations of whatever critters that we've had since Darwin (i.e. since we started looking for them).

[Bravus]

From: http://www.talkorigins.org/faqs/comdesc/section5.html#speciations

The standard phylogenetic tree illustrates countless speciation events; each common ancestor also represents at least one speciation event. Thus we should be able to observe actual speciation, if even only very rarely. Current estimates from the fossil record and measured mutational rates place the time required for full reproductive isolation in the wild at ~3 million years on average (Futuyma 1998, p. 510). Consequently, observation of speciation in nature should be a possible but rare phenomenon. However, evolutionary rates in laboratory organisms can be much more rapid than rates inferred from the fossil record, so it is still possible that speciation may be observed in common lab organisms (Gingerich 1983).

Confirmation:

Speciation of numerous plants, both angiosperms and ferns (such as hemp nettle, primrose, radish and cabbage, and various fern species) has been seen via hybridization and polyploidization since the early 20th century. Several speciation events in plants have been observed that did not involve hybridization or polyploidization (such as maize and S. malheurensis).

Some of the most studied organisms in all of genetics are the Drosophila species, which are commonly known as fruitflies. Many Drosophila speciation events have been extensively documented since the seventies. Speciation in Drosophila has occurred by spatial separation, by habitat specialization in the same location, by change in courtship behavior, by disruptive natural selection, and by bottlenecking populations (founder-flush experiments), among other mechanisms.

Several speciation events have also been seen in laboratory populations of houseflies, gall former flies, apple maggot flies, flour beetles, Nereis acuminata (a worm), mosquitoes, and various other insects. Green algae and bacteria have been classified as speciated due to change from unicellularity to multicellularity and due to morphological changes from short rods to long rods, all the result of selection pressures.

Speciation has also been observed in mammals. Six instances of speciation in house mice on Madeira within the past 500 years have been the consequence of only geographic isolation, genetic drift, and chromosomal fusions. A single chromosomal fusion is the sole major genomic difference between humans and chimps, and some of these Madeiran mice have survived nine fusions in the past 500 years (Britton-Davidian et al. 2000).

More detail and many references are given in the Observed Instances of Speciation FAQ.

[David Koot]

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Bravus said:

Consequently, observation of speciation in nature should be a possible but rare phenomenon.

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So, it has not been observed in nature.

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. . . hybridization and polyploidization (and uncontrolled cross-breeding)

. . . spatial separation, by habitat specialization in the same location, by change in courtship behavior, by disruptive natural selection, and by bottlenecking populations (founder-flush experiments), among other mechanisms.

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Controlled experiments involving cross-breeding. Same family, I assume?

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. . . laboratory populations . . . all the result of selection pressures.

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Once again, controlled experiements in the laboratory, involving cross-breeding within the same family. Correct?

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Six instances of speciation in house mice on Madeira within the past 500 years have been the consequence of only geographic isolation, genetic drift, and chromosomal fusions. . . . some of these Madeiran mice have survived nine fusions in the past 500 years (Britton-Davidian et al. 2000).

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Question for you, professor. Were they still Madeiran mice?

[Bravus]

Read a little more carefully, David. The first para sets up the scientific data, and says that, given the time scales, we might expect to see some speciation, but it would be rare. Which is what I said in my prior post. It does *not* say it has not been or will not be observed.

It then goes on to give a number of specific instances in which speciation has occurred, some under laboratory conditions and some in the wild.

I really have nothing to prove here: you asked if there are cases of speciation, and I provided such cases, along with the reference to where I found them. Feel free to do further research and decide for yourself about those cases.

[David Koot]

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Bravus said:

Read a little more carefully, David.

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I did the first time. And, I reread it as well. Key word is 'expect.' IOW it hasnt happened at this time. Macroevolution has NOT been observed in nature. Cross-breeding has been observed in nature, among populations within the same biological family. It has also been done in the lab, under controlled environments. But, not macroevolution. As for 'time scales,' which you mentioned: Based on what assumptions? At what point do the assumptions project that the speciation will cross what taxonomical lines? On what basis? The position statement on this thread, is that evolution is based upon insupportable assumptions. I am not concerned with the data supporting cross-breeding within the same biological family. I am interested in the data which are claimed to support evolution beyond that family. Where is it? What is the model?

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It then goes on to give a number of specific instances in which speciation has occurred, some under laboratory conditions and some in the wild.

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But, all those occurrences are the result of cross-breeding within the same family--whether under controlled circumstances or otherwise. Is that not correct? And, indeed, the mice were still mice, even after all the cross-breeding. That is not macroevolution. Nor were any of the scientists with whom I discussed this same question, able to come up with any instance of observed macroevolution, from their experience or study.

So, then, getting back to the original issue. As you pointed out, assumptions are made that in the past, macroevolution occurred, over time, from one kingdom to another--from fish to horse, for example. All the experiments and observations involving cross-breeding and mutation, have failed to cross taxonomical lines. They involved populations within the same biological family.

Do you assert that to be incorrect?

David Koot

[bevin]

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As I understand it, the assumption is 'macroevolution = microevolution plus enough time'.

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I would disagree with this on two levels

(a) It is not an assumption, it can be proven to be false if it can be defined.

( The definitions of species, micro-evolution, and macro-evolution are actually to vague to be useful.

How do you decide whether two animals are of the same species?

/Bevin

[Bravus]

To David K: If what you are looking for is change at a level higher than species (and we've discussed the definition of 'species' here before, and found that even biologists don't have a final, consensus definition of it, but 'unable to inter-breed' is one working definition), then that is, under the assumptions that underlie evolution, going to take place on time scales that are *far* longer than human life spans. Remember that such changes would occur as the result of random mutations, the vast majority of which are harmful or do not confer any survival advantage, the tiny minority of which do, and which are inifinitesimal changes each time. It's simply unrealistic, within any understanding of the mechanisms of evolution, to expect to see huge, dramatic changes across taxa higher than 'species' within a human lifetime. No-one has ever claimed that such changes were instantaneous in the 'fish gives birth to an amphibian' sense. The model is by definition gradualist.

One other thing: I'm not sure why your tone toward me is so antagonistic. I'm not an evolutionist. I'm trying to help you, myself and others reading this thread understand evolutionary theory well - because I'm a teacher and I want people to understand. Doesn't mean I support it or advocate it. So your constant demands for me to do more work and provide more proof, while I accept them, grate a bit... I'm not on the opposite side of this question from you, I'm not the adversary.

To Bevin:

(a) for assumption, substitute Popper's 'conjecture': a theory that is being tested for falsification and has not yet been falsified. David K established the language of this thread, and I'm fitting in with that. (And I'm not sure I accept your implication that an assumption is something that is in-principle untestable. It might have to be assumed only until the truth is known. I assume my pay will go into the bank at the end of every month, but once I check the balance that's not longer an assumption.)

( see above on the definition of 'species'. And I agree that our terms aren't well defined, since I was defining 'macro-evolution' as a change of species, whereas David seems to be unsatisfied with that and define it as change at a higher level in the taxonomy.

To both of you: the distinction between micro-evolution and macro-evolution is apparent, not real - it's all one continuous process. My statement that macro-evolution = micro-evolution plus time is a tautology: lots of micro-evolutions constitute macro-evolution, and lots of micro-evolutions take a lot of time to happen.

[Dr. Shane]

First there was the paramecium which evolved into a fish which evolved into a whale which evolved into a hippo which evolved into an elephant which evolved into a monkey which evolved into a man.

[Dr. Shane]

Sorry, I forgot the wooly mamoth is between the elephant and the monkey.

[Bravus]

Hmmm... that's not *quite* how the theory goes... <img src="/ubbtreads/images/graemlins/wink.gif" alt="" />

For a start, you forgot the dinosaurs. And the whale is a mammal, so according to the evolutionary sequence its ancestors actually climbed out of the sea a very long time ago and went back to it some time later.

This 'timeline' is not proportional, it just lists the events... if it was proportional we'd be able to see that the whole length of human civilization, about 6000 years, is just over one millionth of the total time scale. Our lifespans, at 60 years as adults, are one one-hundred-millionth. Not so surprising that we don't see huges changes in that fraction of the whole story...

[David Koot]

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Bravus said:

To David K: If what you are looking for is change at a level higher than species (and we've discussed the definition of 'species' here before, and found that even biologists don't have a final, consensus definition of it, but 'unable to inter-breed' is one working definition), then that is, under the assumptions that underlie evolution, going to take place on time scales that are *far* longer than human life spans.

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Indeed. Cross-breeding happens frequently, but often the offspring are unable to reproduce.

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Remember that such changes would occur as the result of random mutations, the vast majority of which are harmful or do not confer any survival advantage, the tiny minority of which do, and which are inifinitesimal changes each time. It's simply unrealistic, within any understanding of the mechanisms of evolution, to expect to see huge, dramatic changes across taxa higher than 'species' within a human lifetime. No-one has ever claimed that such changes were instantaneous in the 'fish gives birth to an amphibian' sense. The model is by definition gradualist.

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Precisely. Nor have any changes across taxa been observed. Speciation resulting from cross-breeding primarily, adaption, mutation, and so forth has been observed. But all of that has occurred within the same biological family. Attempts at cross-breeding outside the family, or even, in some cases, between individuals within the same family but belonging to different genera, if successful, have resulted in progeny which cannot reproduce. So, no, cross-breeding has not resulted in organisms crossing taxa. IOW cross-breeding has not been shown to be a mechanism for macroevolution. (Nor would it seem to be 'evolution' in a philosophical sense.) Bottom-line: Evolution across taxa is an assumption which, to date, has not been supported by actual observation.

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One other thing: I'm not sure why your tone toward me is so antagonistic.

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????? Such was not my intention or thinking. I did review my posts just now. They don't seem to me, to sound antagonistic. Simply asking questions, and asking for verification. Personally, I believe it is very important to have complete and accurate information, in order to get a clear picture of something. My apologies if my inquisitiveness was perceived as being antagonistic. It is exciting to me, to have the opportunity to discuss these issues with a scientist, and one such as yourself, who is able to carry on such a discussion without resorting to rhetoric.) I am anxious to know more.

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And I agree that our terms aren't well defined, since I was defining 'macro-evolution' as a change of species, whereas David seems to be unsatisfied with that and define it as change at a higher level in the taxonomy.

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Wikipedia:

"Macroevolution refers to evolution that occurs above the level of species. In contrast, microevolution refers to smaller evolutionary changes (described as changes in allele frequencies) in populations."

David Koot

[Bravus]

Ah, OK, I'm sorry if I misread your tone: let's continue along on this inquiry in a spirit of inquiry!

Crossing 'taxa' simply means crossing categories within a taxonomy. Within the biological taxonomy, 'species' is one such category. So if you mean 'crossing categories at levels higher than species (the next one up is genus), then you should probably talk about that specifically, since the examples I quoted constitute 'crossing taxa' at the species level.

Changes of genus, I agree, have not been observed to occur in nature, only in the fossil record. That's as expected, given our timescale, as I described above.

[Bravus]

Bottom line: evolutionary theory *predicts* that we would be very unlikely to see changes at this level occur within our lifetime. The fact that, in fact, we don't observe such changes in our lifetime, therefore, can't be seen as a refutation of evolutionary theory, since the theory's prediction is what we observe.

[Dr. Shane]

Here I thought whales climbed out of the sea once they evolved into hippos and once elephants grew hair they became monkeys.

If you look at a monkey's tail and an elephant's trunk you can see the resemblance there.

[Dr. Shane]

Has there been any "missing links" found in the fossil record?