How can scientists possibly know ... ?? An open exploration thread

[holdon]

No hereditary change of any kind took place? So how did new generations of moths get their colour? Was it painted on them instead of written in their genes? Don't talk nonsense.

Well, as soon as they were submitted to new environmental pressure they changed back to their previous phenotype. So, no genetic information change took place.

 

[Biblewriter]

No hereditary change of any kind took place? So how did new generations of moths get their colour? Was it painted on them instead of written in their genes? Don't talk nonsense.

Colour is inherited. Melanism is governed by the expression of an inherited gene. The predominant colour of the species changed--twice--once to black and once back to white. Both changes were hereditary and illustrated differential reproductive success.

Do you realize how foolish this sounds? The only change observed (even assuming the published data is correct) is two changes in the predominant color of the species. No new genetic material changed, and the proof that it had not changed was that the moths reverted to their original predominant color as soon as the environmental pressure was removed. This is conclusive proof that no genetic change took place.

That's like saying a demonstration of a slapshot is not a demonstration of hockey.



We all know that the biological species concept does not work for all species. However, where you do have exclusively sexual reproduction, it seems to work well. If separate gene pools do not indicate separate species, what, in your opinion, does?

Separated pools of identical genes do not constitute different species. In the old days, no one questioned the fact that a species was a distinct life form, different from all other life forms. But evolutionists like yourself have blurred this distinction. In my opinion, this blurring was intentionally done to makd it possible to demonstrate "speciation," for that is the only way it can be demonstrated.

Actually, evolution seems to do quite well with duplicated, rearranged and modified genetic material.

Only when using your definition of a species.

 

[Mallon]

Separated pools of identical genes do not constitute different species. In the old days, no one questioned the fact that a species was a distinct life form, different from all other life forms. But evolutionists like yourself have blurred this distinction.

The reason why most biologists define species as a "set of interbreeding populations" is because this is a much less subjective definition than "a bunch of animals that look similar".
What definition of species did you use in the "old days", Biblewriter?

 

[holdon]

Only when using your definition of a species.

And evolutionism therefore is a moving target. It evolves everyday...

And to bring back this discussion to the OP, how do scientists (or anyone actually) know anything.
As Popper argued: the decision to want to interpret things rationally, cannot be a rational decision, because that would be circular reasoning. Therefore, the underlying predisposition is an irrational one: a belief that one can correctly interpret things (if not all things) rationally. Now, (rational) reasoning based on a certain belief leads to certain paradigms.

And here is another important point:
A certain paradigm (like Newton's physics) maintains itself and does not allow for new views as they wouldn't fit into that paradigm. The paradigm becomes quite intolerant and this is maintained by all kinds of gravitational forces based on the same paradigm: universities, teachers, textbooks, terms and language, etc.. In this way it becomes like a denomination and one is treated as a heretic if one does not adhere to their system and social exclusion follows. The system becomes a means of power over the individual. Hence claims to "the scientific community" etc..

The irony is that science itself presupposes that there is a higher order. The appeal to logic itself, is that there is indeed logic and order. This again is a presupposition, a belief.
But there could be no science as we know it, if there was no order, no natural laws, etc.. One cannot prove that there must be order in a scientific sense, but one needs to suppose it exists, otherwise science cannot take place.

 

[gluadys]

Well, as soon as they were submitted to new environmental pressure they changed back to their previous phenotype. So, no genetic information change took place.

Do you realize how foolish this sounds? The only change observed (even assuming the published data is correct) is two changes in the predominant color of the species. No new genetic material changed, and the proof that it had not changed was that the moths reverted to their original predominant color as soon as the environmental pressure was removed. This is conclusive proof that no genetic change took place.

Ah, so no genetic change took place.

Guess what. You are absolutely right. The gene for melanism already existed in the population.

But "no genetic change" does NOT mean "no evolution". Evolution is defined as a change in the frequency with which alleles appear in a population. The definition does not include any reference to the appearance of new genetic material Evolution works just as well with already existing genetic material as with mutations appearing for the first time.

Remember, the study of the moths in question was a study of natural selection. As you yourself noted earlier natural selection does not create new genetic material. What it does is change the frequency at which certain traits (and therefore certain genes) appear in the population.

And that change in frequency, is, by definition, evolution.

I emphasize that this IS evolution. Small-scale to be sure. But there is a growing tendency among creationists to deny that this is evolution. And no wonder. Because this is the same evolution that is involved in developing birds from dinosaurs, whales and dolphins from terrestrial mammals and humans from ape ancestors.

There is no division in the process of evolution such that "micro-evolution" does not have macro-evolutionary effects. So it is in the interests of the creationist agenda to deny that evolution within the species is evolution. Use synomyms (variation, adaptation) but never, never call it "evolution" in spite of the fact that that is what it is. Misrepresent the process. Conflate mutation with natural selection and call for evidence of new genetic information when there was no scientific claim made for new genetic information. The claim, in this case, was change in a species trait by natural selection. That was shown and that is evolution.

Arguments based on other definitions or on what was not claimed in the first place are strawman arguments. They have no standing.

Separated pools of identical genes do not constitute different species.

True, but separated pools of identical genes do not remain identical for long. What do you call them after they have become different from each other? What do you call them when individuals from one do not, will not or cannot interbreed with individuals from the other?

In the old days, no one questioned the fact that a species was a distinct life form, different from all other life forms.

And how old were those old days? Darwin reports that in his day, pigeon fanciers did not question that jacobins, fantails, pouters, etc. were all different species of pigeons derived from independent wild ancestral stocks. This is spite of the fact that they will interbreed as freely as different dog breeds given the opportunity. Around the same time, Agassiz and other scientists were sure that the various "races" of humanity were each separately created and therefore separate species. Yet no one questioned that they can and do interbreed.

But evolutionists like yourself have blurred this distinction.

Given the historical facts noted above, I wonder who is really blurring the concept.

 

[gluadys]

The irony is that science itself presupposes that there is a higher order. The appeal to logic itself, is that there is indeed logic and order. This again is a presupposition, a belief.
But there could be no science as we know it, if there was no order, no natural laws, etc.. One cannot prove that there must be order in a scientific sense, but one needs to suppose it exists, otherwise science cannot take place.

Wow. You are quite right. Science does presuppose a higher order and there is no scientific way to affirm that such a higher order exists. Science presumes a world that is real, lawful and intelligible. But it can't scientifically verify that such a world exists.

So where did they get such a presupposition from?

It is no accident that modern science appeared in a Christian context. These are all presuppositions drawn from the Christian theology of the Middle Ages, such as that of Thomas Aquinas.

That the world is real, lawful and intelligible is a logical consequence of the theology of creation (i.e. that the world was created) and the theology of God (i.e. that God is a God of order, not confusion).

This is not to say that all scientists then or now are Christian or even theists. But these Christian-based suppositions were so deeply ingrained in the European worldview that they were accepted as logically necessary by all thinkers whether or not they were believers.

So it is the height of irony to find modern self-styled defenders of Christianity inveighing against the foundational presuppositions of science which most of the Church, throughout history, has also considered to be foundational principles of Christian theology.

When you argue that the world is not rational or not intelligible or knowable, you argue against the Christian presuppositions of the church fathers and of Christian theologians and philosophers throughout history. You argue against the biblical revelation of the character of God and the nature of creation.

 

[holdon]

When you argue that the world is not rational or not intelligible or knowable

But I don't.

 

[gluadys]

But I don't.

Maybe not you personally. I haven't seen enough posts by you yet and your profile does not state your origin of life view.

But it is an argument that has been used repeatedly by YECs on this forum. The irrationality and unintelligibility of creation is supposedly a consequence of the fall. And not being able to know creation, at least pre-fall, means there are no reliable laws of nature for science to find and no foundation for scientific conclusions.

Even the creationists of the 19th century, such as Charles Hodge, http://en.wikipedia.org/wiki/Charles_Hodge
never made such outlandish claims.

They fly in the face of historic Christian orthodoxy.

I agree I have not seen such claims from you personally. But I wonder why you posted the bit about the foundational presuppositions of science if you agree there is nothing wrong with them?

 

[holdon]

But I wonder why you posted the bit about the foundational presuppositions of science if you agree there is nothing wrong with them?

But did I say there is nothing wrong with them? I first would have to know what they are. To the extent that science discovers the order (also called "laws") of the ceated nature, I feel confident that they will discover that there must somehow be a "law giver". In other words if science remains conscient of the transcendent origin of origins, one can remain hopeful. It might even make it easier..... to believe in creation.

 

[gluadys]

But did I say there is nothing wrong with them? I first would have to know what they are.

I have already stated the basic presuppositions.

1. The world is real. i.e. it is not, as claimed in Hindu theology, a grand illusion-- a Matrix-style hologram. We are not brains in a vat collectively (or solipsistically) conjuring up the cosmos from our brainwaves. It is really out there.

(For a Christian, this follows from the doctrine of Creation. God made a real world.)

2. The world is orderly. It operates in a pattern of cause and effect that once deciphered makes it possible to predict the future recurrence of that pattern e.g. to predict eclipses in the future from the known pattern of planetary movement. This also makes it possible to retrodict past eclipses which were not observed or recorded.

(For a Christian, this follows from the conviction that God is a God of order, not confusion, and from the promises given in scripture that the ordinary processes of nature designed to sustain life will not be disrupted.)

3. The order of the world is intelligible. We can discover it and understand it by the use of our senses and the application of our reason to our observations.

(For a Christian this follows from the conviction that God made humanity in God's image, capable, to a limited extent*, of following God's thoughts and entering into comprehensible communication with God.

*Obviously, there are also mysteries in God well beyond all human or even angelic comprehension.)

To the extent that science discovers the order (also called "laws") of the ceated nature, I feel confident that they will discover that there must somehow be a "law giver". In other words if science remains conscient of the transcendent origin of origins, one can remain hopeful. It might even make it easier..... to believe in creation.

Not really. The presuppositions are presuppositions and in themselves cannot be proven but must be assumed. So they cannot lead to discovering a deity. And if the first presupposition (the world is real) is incorrect, the discovery of particular patterns or regularities in nature ("laws of nature") are just patterns in our imagination, like the world itself.

That there is a reality which transcends the physical reality revealed through sense, reason and science must always remain a matter of faith. It is not discoverable by scientific means.

I can never figure out why some Christians have a problem with that. Isn't the point to be people of faith?

Most of the scientists in this forum, as well as lay defenders of science like myself, already believe in creation. Why do you think people need more than faith to believe?

Do you remember Jesus' parable of the rich man and Lazarus? I think it a good caution. When the man pleads with Abraham to send Lazarus to his brothers, Abraham replies, "If they do not believe Moses, they will not believe even if one should rise from the dead." If people do not believe in God with the evidence we already have, what good will more evidence do?

Note the first line in my signature.

 

[holdon]

The presuppositions are presuppositions and in themselves cannot be proven but must be assumed. So they cannot lead to discovering a deity.

Because they must be assumed and therefore admittingly cannot be proven, they can be discovered. But not discovered in a scientific sense, but in transcedental sense. We're back to faith.

Why do you think people need more than faith to believe?

I didn't say that.

Do you remember Jesus' parable of the rich man and Lazarus? I think it a good caution. When the man pleads with Abraham to send Lazarus to his brothers, Abraham replies, "If they do not believe Moses, they will not believe even if one should rise from the dead." If people do not believe in God with the evidence we already have, what good will more evidence do?

You're absolutely right. But I would put it this way: Believing depends not on evidence in the first place, but on willingness. And therefore more evidence does not necessarily help. Evidence, facts if you will, is the object of science. But that is only part of the real world. And "fact" means "made". But that begs the question: Who made them?

 

[gluadys]

Because they must be assumed and therefore admittingly cannot be proven, they can be discovered. But not discovered in a scientific sense, but in transcedental sense. We're back to faith.

Which is exactly where we should be.


Note, however, that there is considerable difference between accepting the presuppositions by faith and accepting the conclusions of science. If the presuppositions are true, then what we learn of the physical world by sense and reason is also necessarily true. There are only two bases on which scientific conclusions can be opposed:

a) new evidence which contradicts conclusions reached on the basis of current evidence. Such new evidence calls for at least a revision of current theory, sometimes for a replacement of current theory with a better theory.

b) denial of the truth of the presuppositions.

Creationists have come to the point where they cannot deny evolution via route a) so they are trying route b). But this puts them at odds with historic Christian theology about God and creation.

 

[holdon]

Note, however, that there is considerable difference between accepting the presuppositions by faith and accepting the conclusions of science. If the presuppositions are true, then what we learn of the physical world by sense and reason is also necessarily true.

But the question is how can you know?

There are only two bases on which scientific conclusions can be opposed:

a) new evidence which contradicts conclusions reached on the basis of current evidence. Such new evidence calls for at least a revision of current theory, sometimes for a replacement of current theory with a better theory.

This seems to happen every once in a while but because of paradigm constraints it takes a lot of new evidence to make anybody even listen. Remember Galileo?

b) denial of the truth of the presuppositions.

Creationists have come to the point where they cannot deny evolution via route a) so they are trying route b). But this puts them at odds with historic Christian theology about God and creation.

What do you mean?

 

[shernren]

This seems to happen every once in a while but because of paradigm constraints it takes a lot of new evidence to make anybody even listen. Remember Galileo?

Galileo was scientifically accepted but religiously rejected. He is not a good poster boy for your case. (Unless you're buying into creationist propaganda about Aristotelianism ... )

 

[gluadys]

But the question is how can you know?

Basic logic. You can have a chain of reasoning that sounds good, but the conclusions are false because the rules of logic have not been respected. In this case we say there has been a logical fallacy. Google "logical fallacy" and you can find plenty of examples of fallacious reasoning.

You can have a chain of reasoning in which there is no logical fallacy, so the conclusion is valid. Yet it may not be true because one of the premises or presuppositions is not true.

But in the case where there is no logical fallacy and the premises are true, then the conclusion is also true.

Scientific conclusions which have the support of the majority of the scientific community have been thoroughly checked out for logical fallacies and also for agreement with observed evidence.

So the only other basis on which they cannot be true are the two I named: undiscovered evidence which contradicts the theory or the presuppositions themselves are not true.

Can we know that the basic presuppositions are true? No. We can't. That is why they are assumed. But if they are true, the rest of science follows at least as far as current evidence takes us.

Now which of the basic presuppositions would you consider questionable?

Is the world not real?
Is the world not lawful? or
Is the world not intelligible?

What do you mean?

Just what I said. Many creationists have given up trying to show that the evidence contradicts evolution. So they are trying to claim that the basic presuppositions of science are not true.

Trouble is, those are also some pretty basic assumptions of Christian theology too.

 

[Biblewriter]

The reason why most biologists define species as a "set of interbreeding populations" is because this is a much less subjective definition than "a bunch of animals that look similar".
What definition of species did you use in the "old days", Biblewriter?

I don't recall anyone ever using such a loose definition of a species. I suppose the most accurate definition as we used to use the word would be a set of lifeforms that share a common genetic structure. I well remember an old article about a flower species that grew in the Alps. A biologist brought some of them to his laboratory in the lowlands of France, and was surprised to find them growing as a common species of the lowlands. The conclusion was that the alpine species and the lowland species were really the same species. The difference was only in how it expressed itself in the different environments.

 

[Mallon]

I don't recall anyone ever using such a loose definition of a species. I suppose the most accurate definition as we used to use the word would be a set of lifeforms that share a common genetic structure. I well remember an old article about a flower species that grew in the Alps. A biologist brought some of them to his laboratory in the lowlands of France, and was surprised to find them growing as a common species of the lowlands. The conclusion was that the alpine species and the lowland species were really the same species. The difference was only in how it expressed itself in the different environments.

"A set of lifeforms that share a common genetic structure"?
How did you determine their genetic structure, back in the "old days"?
It sounds to me, from your alpine flower example, like you used the same definition we use today. That is, populations capable of interbreeding.

 

[Biblewriter]

"A set of lifeforms that share a common genetic structure"?
How did you determine their genetic structure, back in the "old days"?
It sounds to me, from your alpine flower example, like you used the same definition we use today. That is, populations capable of interbreeding.

That is an alternate definition that I had thought of using. But that is not the definition that is being used by evolutionists in this discussion. If the capability of interbreeding is not the definition, but only the fact of physical interbreeding, it is very easy to demonstrate speciation. But if the capability of interbreeding is the definition, all the purported examples of speciation break down.

 

[shernren]

That is an alternate definition that I had thought of using. But that is not the definition that is being used by evolutionists in this discussion. If the capability of interbreeding is not the definition, but only the fact of physical interbreeding, it is very easy to demonstrate speciation. But if the capability of interbreeding is the definition, all the purported examples of speciation break down.

You'd be surprised. This experiment was performed in 1989 and only took eight generations of flies to complete:

source: http://en.wikipedia.org/wiki/Speciation

 

[gluadys]

That is an alternate definition that I had thought of using. But that is not the definition that is being used by evolutionists in this discussion. If the capability of interbreeding is not the definition, but only the fact of physical interbreeding, it is very easy to demonstrate speciation. But if the capability of interbreeding is the definition, all the purported examples of speciation break down.

But the fact of physical interbreeding is decisive. If two populations do not interbreed, there is no gene flow between them. Whether they are theoretically capable of interbreeding (and can even be made to do so in captivity) they are separate species in nature because they do not interbreed,

E.O. Wilson defines a biological species as "a population whose members are able to interbreed freely under natural conditions."

"Under natural conditions" is the important qualifier. Zookeepers have successfully crossed lions and tigers, but such specimens are confined to zoos and do not a species make. To consider lions and tigers a single species one needs to find them freely interbreeding in nature. Wilson notes that this was not the case even when both species had a much larger range with overlap between their ranges so that interbreeding in nature was not prevented by geographical separation as it is today.

He also goes into why it is unlikely that a lion and a tiger would mate under natural conditions.