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Author Topic:   Evolutionary Biology as a Science
Rahvin
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Posts: 4032
Joined: 07-01-2005
Member Rating: 9.2


Message 1 of 34 (500831)
03-02-2009 4:56 PM


This could be extremely broad, but it's an attempt to redirect the ongoing discussion with Kelly from the "I'm not an Atheist!" thread where the discussion is extremely interesting but also wholly off-topic.
I'm going to try to constrain this to a discussion on whether "Creation Science" and "evolution" are actually science. Kelly has claimed that "Creation Science" is in fact scientific, while disparaging evolution as unobservable and unscientific.
Let's start with some definitions:
Science
As it applies to this discussion, the term science refers to any branch of study that follows the scientific method. The scientific method involves making a set of observations, creating a hypothesis explaining those observations, making predictions (or logical deductions) from the hypothesis, and then testing those predictions through experiments or the collection of additional evidence. This is followed by modifying or discarding the hypothesis based on new evidence.
This means that unfalsifiable hypotheses are not part of the scientific method - all hypotheses must be testible, and therefore falsifiable if a certain set of conditions are true.
This also means that pre-conceived conclusions are not scientific. Science examines the evidence and draws conclusions objectively and with the express purpose of minimizing or eliminating personal bias from any sort of "world view." This is why the scientific method involves rigorous testing as well as the peer review process - theoretical frameworks are judged on the accuracy of their predictions, not based on how they fit in a pre-defined "world view."
Evolution
Evolution, simply stated, is change over time. The Theory of Evolution explains the variety of life observed on Earth through the mechanisms of mutation guided by natural selection and genetic drift. Small mutations in each generation are made more or less prevalent in a population due to natural selection, causing the population to change as a whole in response to new selective pressures. When populations are divided geographically, the generational changes occur independantly and in response to different slective pressures, eventually resulting in new species (and in the broader sense and over longer timescales, new families, phyla, genara, etc).
The Theory of Evolution has nothing to do with the origin of life itself - evolution is the process of change in populations of already-existing lifeforms over multiple generations, and so cannot possibly apply to the origin of life.
The Theory of Evolution does not have anything to do with "morphing," where one species "turns into" another. Evolution occurs to populations, not individuals, and over multiple generations. This is not Pokemon.
The Theory of Evolution does predict that all features should not be unique, but should rather be slightly modified versions of already-existing features from other species. This can and does result in additional or less complexity, where redundant systems can evolve in an organism and then change in function compeltely or establish an alternate method for the same purpose. So-called "irreducibly complex" systems are the result of re-purposed features or systems in which redundant steps have been added and part of the original chain removed.
Creation Science
Creation Science, or Creationism, is the process of attempting to prove a literal interpretation of Creation as described in Genesis, where living things do not evolve but are rather Created, whole, as a divine miracle.
Is Evolution science?
Science requires that we make observations, establish a hypothesis, make predictions from the hypothesis, test those predictions, and modify, keep, or discard the hypothesis based on teh results.
The Theory of Evolution began with the observation that various features of populations of birds changed over generations - beaks would become longer or shorter over a few generations, for example. A hypothesis was made: changes in given populations are guided by natural selection. This predicts that, to use the bird example, beak length should be guided by the food source available, where certain food sources favor longer beaks and others favor shorter beaks. This hypothesis was borne out via direct observation - on islands where the same species resided, beak lengths were directly correlated to food source.
So far, this meets the requirements of the scientific method. But the Theory of Evolution has...evolved...since Darwin's day.
We now have an understanding of genetics and the fossil record, as well as a greater understanding of the form and functions of features in extant living organisms. This has added a tremendous amount of data to be examined to test the predictions of the Theory of Evolution.
Evolution predicts that all life on Earth should be related to one or more (but msot likely one) distant ancestor species. We should see less variety in life forms the farther back we look. This is borne out in the fossil record. Evolution predicts that closely related species should be similar also on teh genetic level. This was also verified, but genetics also gives us various markers (typically in the form of genetic damage from viral infections and mitochondrial DNA) that can show us exaxtly when various species branched apart and had their final common ancestor. Further, genetics showed us the specific method by which traits are inherited, and showed us how "information" can be changed, added, or subtracted in each generation - the specific mechanisms behind mutation. In this case, not only was the prediction verified, we obtained more evidence than we expected in support of evolution - in fact, evidence that doesn't make any sense without evolution.
These are just a few examples. But as you can see, the Theory of Evolution is a well-tested theoretical framework that adheres to the scientific method - it is science.
Is Creation Science...science?
Creation Science begins with a literal reading of Genesis - species are specially Created, and do not rise from pre-existing species. It then proceeds to take observations in support of this "hypothesis" - dogs cannot give birth to cats, and each species is its own "kind."
But has this hypothesis been tested? Given that scientists have directly observed the formation of new species both in the lab and in the wild, the Creation hypothesis should have been at the least modified, if not outright discarded.
Creation Science does not begin with observations, it begins with a conclusion. It then seeks to "interpret" evidence in support of the pre-established conclusion. Contradictory evidence is ignored, or "re-interpreted" to support the conclusion anyway. Instead of modifying the hypothesis based on new information, the "interpretation" of non-supporting evidence is modified.
Clearly, this is not in line with the scientific method. This is apologetics - a form of rationalization used to justify a belief in the face of contradictory evidence.
It would seem that while the Theory of Evolution is valid science, "Creation Science" is not scientific at all.
But now let's go over some of Kelly's specific claims in the previous thread, since they detail some of the claims of Creation "Science":
1. A trait will alter because of a stimulus. 2. The trait will return to the norm if left to nature or returned to its original conditions. 3. No new information is added to the DNA.
Traits do nto alter due to stimulus. Traits alter randomly - mutation obeys the constraints of chemistry, but is otherwise nothing more than the result of copying errors in the DNA replication process.
The spread of the trait throughout the population is dictated by the stimulus - the selective pressure. Irrelevant changes will go mostly unnoticed; mutations that give a benefit in a given environment will tend to be more common in each generation as the more successful individuals out-reproduce their cousins; mutations that are detrimental in a given environment will tend to die out. Whether a given trait is positive, negative, or neutral is dictated by the environment - the amount of competition, the source and availablitiy of food, temperature, etc. When the environment changes, the traits expressed in a population tend to adapt over several generations as those with beneficial small changes outcompete those without such changes.
But the most egregious error in Kelly's claim is that "no new information is added to the DNA."
This is false.
Mutations are copy errors in the DNA replication process. DNA is comprised of four basic interchangeable building blocks - abbreviated with A, T, G, and C. Let's say we have a small part of a DNA molecule:
TGCCTAGC
When this 8-letter gentic "word" is transcribed, a mutation may occur. The offspring of this organism could have any of the following "words" instead:
TGCCTAGCC
TGCCTAG
TGCGCTAGC
TGCATAGC
Mutations can result in teh addition, subtraction, or simple change of genetic information from one generation to the next. They are also extremely common - it is estimated that human beings each posess several hundred small mutations, genetic information that was not inherited from their parents and is instead the result of copying errors during reproduction.
We can observe direct evidence of this in the lab, and in fact it's the cause of the so-called "superbugs" that occasionally go around the news outlets.
Bacteria reproduce asexually - they simply divide. Each is a clone of its parent. Without new genetic information, no new traits could ever evolve.
And yet something curious happens in an experiment replicated frequently around the world:
Begin with a single bacterium - one cell. Allow it to reproduce in a petri dish until a sizeable colony is established. All of the organisms should now be descendants of the original bacterium.
Now introduce a selective pressure - an antibiotic.
The vast majority of the popualtion will die - but invariably some will remain. These few will thrive in the petri dish where they simply survived before; with less competition, the antibiotic-resistant trait will flourish and become nearly universal.
Where did this resistance come from? If each individual is a clone of its parent, how did this new trait arise?
The answer is simple: a copying error during replication resulted in a slight change that, while irrelevant at first, became a positive adaptation when the enviroment changed with new selective pressures.
Obviously, new "information" can be and is added to DNA all the time. Kelly's claim is directly refuted by commonly-observed evidence and the simple mechanisms by which genetic replication work.
The argument for evolution is that species will change slightly over time and eventually change into something completely different and will over eons of time eventually become a new species. This theory was thought up as a hypothesis and as science advances, the facts have not been found to support it, but much has been provided to dispute it. There are no examples in nature that even remotely indicates a change of species through evolution.
Curiously, this is not what any biologist will tell you. Neither will any paleontologist or geneticist or zoologist agree with your claims regarding their particular fields of study.
As I said to you in the other thread, we have directly observed new species arising from populations of previously existing species. We have seen it both in nature and in the laboratory. Direct observation contradicts your claim that nature provides no examples of species changing through evolution. You cannot get a more clear falsification than that, Kelly.
The fossil records have zero transitional forms. Even fossilized insects such as spiders and ants that have been dated to pre-historic times are identical to modern day spiders and ants.
Examples of transitional fossils abound in the fossil record. Would you like to see some?
Here are just a few of the transitional species relating to hominids - us.
Here are some transitional fossils relating to the evolution of jawbones.
There are more - many more. Technically, every species is transitional, existing partway between its ancestor species and its descendant species. But even those examples you're looking for, where we see the direct transition from one type of organism to another (single-celled to mutlicellular, invertibrate to vertibrate, dinosaur to bird) are plentiful. All you need to do is look. The resources are available online - I found the above images in moments.
There are three critical flaws in the theory of evolution through gradual change: Dysfunctional change,
Many changes are dysfunctional; occasionally a dysfunctional change can become a beneficial one when the environment provides a new set of selective pressures.
the DNA code barrier, and natural selection removes DNA information but does not add new information.
False, as detailed above. DNA can be added to, subtracted from, or simply change in any given mutation, allowing for a net increase in diversity over time - which is exactly what we see in nature.
Conclusion
It would seem, Kelly, that your claims stem from ignorance and reliance on sources whose claims are outright falsehoods. Creation "Science" is no such thing, and the Theory of Evolution is a valid branch of scientific study.
"Is it science?" please. I understand that this is extremely long and broad, but the Kelly debate needs to have its own thread, and I think Kelly's claims deserve being addressed.
Edited by AdminNosy, : No reason given.

Replies to this message:
 Message 2 by AdminNosy, posted 03-02-2009 5:18 PM Rahvin has replied
 Message 4 by Kelly, posted 03-02-2009 5:43 PM Rahvin has replied

  
Rahvin
Member
Posts: 4032
Joined: 07-01-2005
Member Rating: 9.2


Message 8 of 34 (500861)
03-02-2009 6:38 PM
Reply to: Message 2 by AdminNosy
03-02-2009 5:18 PM


Re: Contrast with the other topic
Hey Nosy,
I will promote this but I'd like you to reply immediately clarifying that we are not mentioning "Creation Science" here. That is for the other thread.
ABE In fact I'd like a quick topic title change to something like
"Evolutionary Biology is a Science" leaving out the mention of creationism please.
The OP as written contains a lot that addresses Creationism, but I'm happy to continue with the limitations you mentioned - the other thread was posted while I wrote this one.
I'll try to edit out the Creationism references and make the OP reflect the newly-defined topic.

This message is a reply to:
 Message 2 by AdminNosy, posted 03-02-2009 5:18 PM AdminNosy has not replied

  
Rahvin
Member
Posts: 4032
Joined: 07-01-2005
Member Rating: 9.2


Message 10 of 34 (500872)
03-02-2009 7:15 PM
Reply to: Message 4 by Kelly
03-02-2009 5:43 PM


Re: Starting with an accurate description of what creation Science is
Hi Kelly.
As you can see above, AdminNosy as redefined the bounds of this thread a bit from what I stated in my opening post - this was done to make a more concise debate possible, particularly in light of the other, similar thread that was posted while this one was being written. Sorry for the confusion - overly broad topics are usually discouraged here to promote a debate that is less likely to veer off onto tangential discussions.
I'll do my best to address your post in light of the new topic title.
Science means *knowledge*, not speculative philosophy or naturalism.
Inaccurate. Science does not mean "knowledge." Science is a specific methodology of study - the scientific method. You are correct in that science is not "speculative philosophy" or even necessarily naturalism, but science is not "knowledge."
Science does not make many absolute statements - it attempts to provide explanatory models for observed evidence to the greatest degree of accuracy possible. While we "know" how gravity works, that "knowledge" is tentative - new evidence can force us to modify or discard our existing theoretical framework at any time. In fact, this has already happened with regards to gravity - Newtonian gravity was supplanted by Einstein, though the Newtonian model is still accurate enough for application on the human scale.
The essence of the scientific method is measurement, observation, repeatability. Falsifiability is the necessary criterion of genuine science. A hypothesis must--at least in principle--be testable and capable of being refuted, if it is truly scientific.
This is true.
Neither model of macroevolution or creation with regards to origins is scientific in this sense. Neither one can be tested because we cannot repeat the history of origins.
False.
Testing does not require direct observation of events; we can know that George Washington existed without having lived at the same time, and we can determine guilt in a murder trial without having observed or even repeating the events.
Testing requires making predictions (or logical extrapolations) that are then borne out or falsified by experiment or additional evidence.
Further, "macroevolution" as defined as the rise of new species from extant species has been directly observed, as I've pointed out.
Even if the evolution of new species had not been directly observed, we are surrounded by mountains of evidence that invariably leads only to the conclusion that new species arise from extant species through a gradual process of mutation guided by natural selection. As I stated in my OP, the fossil record, genetics, vestigial organs, and direct observation of extant species all lead to the conclusion that all life on Earth is related, sharing a common ancestor.
However, the results of origins can be observed and tested regardless of what we believe about how they came about. Whether we are a creationist or an evolutionist, we can each test and observe the scientific data, the evidence of life.
Indeed we can; it is curious, then, that you have already ignored evidence as presented in my OP and by others in this and other threads regarding evolution.
We can define two models of origins and then make comparative predictions as to what our observations should find if macroevolution is true, and conversely, what we should find if creation is true. The model that enables us to best predict the things we should then find to be true on observation is the model most likely to be true even if we cannot prove it by actual scientific repetition.
This is a false dilemma; if evolution is false, creation is not necessarily true. By the same token, if creation is false, evolution is not necessarily true. You cannot prove one by disproving the other - a third, as yet undetermined mechanism could be behind the observed variety of life on Earth.
However, to constrain this to a discussion on evolution as AdminNosy has required, let's stick to talking about the predictions and evidence for or against the Theory of Evolution, and whether it is or is not science.
According to the evolution model, the origin and development of all things can be explained in terms of continuing natural laws and processes operating in a self-contained universe.
The Theory of Evolution makes no statements with regard to the Universe, self-contained or otherwise. That's the purview of cosmology, an entirely different branch of study than biology.
The Theory of Evolution deals only with living things, and the rise of new varieties of living things from already-existing varieties.
The basis of the creation model is that at least some things must be attributed to completed supernatural processes in an open universe. In this form the creation model is completely independent of the biblical record, and can be evaluated solely in terms of the scientific data. See "What is Creation Science?" Morris/Parker
I'm afraid I'll have to disregard this as off-topic, since we're restricting ourselves to a discussion on whether the Theory of Evolution is or is not scientific.
But now, I need to ask why you chose to post a reply to me without actually addressing anything in my opening post? You didn't quote me once - I understand not yet knowing how to use quote tags for the easy-to-read boxes this board is capable of, but you didn't even manually quote a single sentence from my OP.
I've taken the time to address each of your points specifically and in detail, and so far you have taken the time to write replies that do not address my claims and in fact outright ignore large segments of what I've said.
If I can have the courtesy to reply to your statements, can you give me the same courtesy? Otherwise, we aren't having a conversation, we're simply talking at each other. That is not productive.

This message is a reply to:
 Message 4 by Kelly, posted 03-02-2009 5:43 PM Kelly has replied

Replies to this message:
 Message 11 by Kelly, posted 03-03-2009 9:42 AM Rahvin has not replied

  
Rahvin
Member
Posts: 4032
Joined: 07-01-2005
Member Rating: 9.2


Message 25 of 34 (500959)
03-03-2009 3:39 PM
Reply to: Message 23 by Kelly
03-03-2009 3:14 PM


Re: No offense
But I find that very hard to believe given the fact that no one here demonstrates to me that they know the first thing about what Creation Science is.
We know very well a variety of versions of Creation "Science" that have been presented to us in the past. Those versions may be different from yours - but unless and until you describe the Creation Science you are talking about, all we can possibly address are the versions we've seen before.
Further, Creation Science is not the topic of this thread. The topic, as you can see in the title, is a discussion on whether the theory of Evolution qualifies as scientific.
I am more than willing to bring the arguments here and discuss or debate them.
then do so.
But first I need to know that everyone at least recognizes what Creation Science really is. I think that people here need to know where I am really coming from and not just where they perceive or think I am coming from.
Then describe what your version of Creation Science is, and tell us where you are coming from.
Do not respond with the title of your favorite book again - we aren't here to debate the author of the book, because the author is not here to respond. We are here to debate you. If you cannot are are unwilling to make an argument in your own words, then you are clearly incapable of an actual debate. All we're asking is that you make an actual argument and then support it.
Respect is something that can only benefit everyone who participates in this forum.
Respect is earned, and further is irrelevant to the argument.
It has to go both ways.
You have failed to respect anyone on this forum by failing to respond to anyone's actual arguments and complaining in posts like this one rather than actually addressing the topic.
From my point of view, everyone here is quite disrespectful towards Creation and its adherents, and why? Because you don't really know what Creation Science is or what the claims are. I know this based on everything I have read here.
Incorrect. We have been presented with myriad versions of Creationism - some have called themselves "Creation Science." None qualified as scientific. None supported their arguments. There was nothing to respect at all in the vast majority of cases.
Now kindly address the topic of this thread or stop participating in it. If you'd like to discuss the topic, do so. If not, participate in a different thread where you will be on-topic, or make one of your own.

This message is a reply to:
 Message 23 by Kelly, posted 03-03-2009 3:14 PM Kelly has not replied

  
Rahvin
Member
Posts: 4032
Joined: 07-01-2005
Member Rating: 9.2


Message 28 of 34 (501305)
03-05-2009 3:06 PM


Hey Kelly, over here!
Since Nosy (rightfully) is performing a topic-check on the Creation Science thread, I'm copy/pasting my offtopic reply to the thread where it is more appropriate in the hopes that Kelly will follow:
Real evolution (macroevolution) requires the expansion of the gene pool, the addition of new genes and new traits as life is suppose to move from simple beginings to ever more varied and complex forms (molecules to man..fish to philosopher)
And as I've posted to you before, mutation can and does add, subtract, and change genes. You've asserted that DNA cannot be added to during replication, and yet you've failed to support your assertion of even provide the mechanism that supposedly prevents this from happening. Meanwhile, multiple people have told you repeatedly that genetic information is frequently added during DNA replication in teh form of mutations - and you've simply ignored our statements.
Further, this is irrelevant to my argument. I showed you that actual, real new species have formed from pre-existing species. Your nonsense about genetic information is irrelevant to that point, Kelly. You cannot refute direct observation.
You seem to think that these species inability to breed anylonger is a sign of evolution, but I think the opposite is true. Each variety now has a smaller gene pool than the original and a restricted ability. The long term results is likely extinction because these new variations which you call new species are now weaker.
Upon what do you base this assertion Kelly? Reality seems to disagree with you. Do you remember my example of bacteria that evolve resistance to antibiotics? Scratch that - I'm rather certain you never even read it. So I'll repeat myself, despite the fact that you seem to be incapable of reading a person's post and actually responding to their points. Please prove that impression wrong and provide an honest debate by replying to my points.
Bacteria reproduce asexually. Each new bacterium is actually a clone of the original - no new information can be added, right? That's what you're claiming, anyway.
But if we begin an experiment with just one bacterium, a single cell, and let it reproduce into a colony something curious happens.
If we introduce an antibiotic to the colony, invariably most will die - but some will live, and thrive with the new lack of competition. Continued reintroduction of the antibiotic will be less and less effective as the bacteria develop a resistance.
How did this happen, if no information was added, since all of the bacteria are copies of the original?
The answer is that random mutation does result in the formation of new features. All the time, Kelly. This experiment is reproduced frequently in the lab, and this exact process is what results in the so-called "superbugs" you may have read about in the news.
Clearly, your assertion that new features cannot evolve is false. Once again you are contradicted by direct observations in reality, Kelly. You are wrong.
So now we have demonstrated that new traits do form spontaneously as a result of mutation, despite your claims to the contrary. Further, we've demonstrated that new species do arise from pre-existing species.
Exactly what part of your position remains, Kelly? All of your claims seem to have been utterly refuted. Will you continue to ignore the refutations, will you lie, will you shift the goalposts again, or will you actually admit that you were wrong and concede the point?

Replies to this message:
 Message 29 by Kelly, posted 03-06-2009 7:00 PM Rahvin has replied

  
Rahvin
Member
Posts: 4032
Joined: 07-01-2005
Member Rating: 9.2


Message 30 of 34 (501578)
03-06-2009 7:10 PM
Reply to: Message 29 by Kelly
03-06-2009 7:00 PM


Re: Oops, so sorry it took me so long
But this old argument is useless.
Quite to the contrary.
Mutations do not explain drug-resistant bacteria.
Really? When the parent of all of the subject population had no such resistance, and a portion of the child population does, where did this resistance come from given that bacteria reproduce by copying themselves?
Further, when we examine the genetic structure of the bacteria, we can actually directly observe the spontaneously altered genes that caused the resistance. How do you explain this, without mutation?
Scientists discovered that bacteria were resistant to certain antibiotics even before the antibiotics were invented.
...that's a self-contradiction, Kelly. If antibiotics hadn't been yet invented, how could scientists discover that bacteria are resistant to them? That's like saying that scientists discovered that driving without a seatbelt is dangerous before cars were invented.
Contrary to popular opinion, drug-resistance in bacteria does not demonstrate evolution. It doesn't even demonstrate the production of favorable mutation.
How else do you explain the sudden, spontaneous appearance of a new trait? How do explain the observed alteration in the genetic code of an organism that reproduces by essencially cloning itself?
It does demonstrate natural selection, but only selection among already existing variations within a type.
There were no variations of teh type that existed, Kelly - ALL of the individuals in teh entire population were descendants of a single parent bacterium, and they all reproduce by copying themselves. Where did the variation come from if not mutation? We can directly observe the genes, and they weren't present in the parent bacterium.
Edited by Admin, : Rahvin said "...and a portion of the parent population..." when I think he meant child population. Apologies if I have this wrong, but in that case I'm very confused.

This message is a reply to:
 Message 29 by Kelly, posted 03-06-2009 7:00 PM Kelly has not replied

  
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