Evolution: still a theory?

[wake]

.

Hello all,

Following a recent discussion, I have come to ask myself: why is evolution still regarded as a theory?

After all the discoveries, research, carbon dating, fossil evidence, observation, etc., etc., why can't we positively state that evolution has occured or is occuring even today?

What's missing?


sincerely,

wake


~

[geonuc]

Remember that in scientific terms, 'theory' means a pretty strong argument. The popular phrase "It's just a theory" grossly mischaracterizes the meaning.

And evolution is a very strong theory.

[Noclevername]

Every theory in science is a theory. Einstein's General Relativity, which has been proven up, down and backwards, is a theory. Gravity is a theory. In science, if it's backed by evidence, it's a theory. If not, it's a hypothesis. The popular usage of the word "theory" has blurred this definition, but to scientists the original meaning is the correct one.

[Hornblower]

We have enough forensic evidence and knowledge of genetics to infer that evolution occured over the eons with a very high level of confidence. That makes it a very strong theory. What we cannot do is go back in a time warp and absolutely confirm it by observing it in progress. If a creationist were to assert that an almighty supernatural creator made it happen all at once and faked the physical and chemical properties to create an illusion of evolution, science would have no means of refuting it.

Do not confuse my sense of a theory with what many disbelievers mean when they say "only a theory". They are thinking in terms of a wild guess or hunch. A truly scientific theory is developed by examining all available evidence, and is revised if necessary when additional evidence is found and critically analyzed.

[Disinfo Agent]

why can't we positively state that evolution has occured or is occuring even today?

Oh, but we can!

Evolution is a Fact and a Theory.

[ravens_cry]

Evolution is a theory and as such can not be become a law. That doesn't mean it isn't a very strong theory. Science is about what is provable, and while I personally believe a God had a hand in the making of the universe and even us, that is my belief, but this is a rather sterile avenue for the presuit of understanding things. It would and did become easy to say ' god did it' when ever an anomaly pops up, instead of looking deep into the mechanisms and forces behind phenomena.
Besides, a lazy god would have use for evolution, it would mean they wouldn't have to come back every few thousand years to adjust things. So, though it may be completely against what I used to believe, I do think now that the mechanism of evolution and the concept of a god even in a philosophical sense, aren't completely incompatible.
I personally think evolution happens, but it isn't all that happens. But anyone is free to agree or disagree with that, because it is an unprovable belief, it is part of my assumption if you will. Peace Out.

[Laguna]

wake, remember:
http://www.notjustatheory.com

[wake]

.

Thanks for the links. VERY interesting.

So... One more question, if I may. A good theory can be used to make predictions about the outcomes of experiments, right? Are there examples of biological experiments where, let's say, Darwin's theory predicted the results?

oh geeez! That's two questions.

wake


~

[HenrikOlsen]

Correct.

It can only predict in the general sense in that it can say that adaption will happen, it can't predict how this adaption happens specifically, since a fundamental part of evolutionary theory is that adaption is based on random variations having different probabilities for being passed on.

[Disinfo Agent]

Does the theory of evolution produce predictions? Yes, it does.

Of course, they are not exact predictions like the ones you'll find in kynematics or astronomy. You can't predict a fossil find the same way that you can predict an eclipse. But still each new piece of evidence that has been unearthed was consistent with evolution -- and it need not be!

[KKHS]

why is evolution still regarded as a theory?

Because it still explains alot of stuff, as it always have

[AndreH]

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Thanks for the links. VERY interesting.

So... One more question, if I may. A good theory can be used to make predictions about the outcomes of experiments, right? Are there examples of biological experiments where, let's say, Darwin's theory predicted the results?

oh geeez! That's two questions.

wake


~

Correct.

It can only predict in the general sense in that it can say that adaption will happen, it can't predict how this adaption happens specifically, since a fundamental part of evolutionary theory is that adaption is based on random variations having different probabilities for being passed on.

For what Henrik says:

I would use the development of Multiple Antibiotica Resistent Bacteria or the breeding of dogs (cats, cows...).

Evolution would predict that if the enviroment puts a pressure on a species which favours the survival of individuals with a certain property than the species will evolve over some generations in the way that this property is common in all the species.

In case of bacteria it is the property of being not killed by a substance that is poison for all the rest.

Concerning animals it is an arbitrary choosen feature which some human thinks would be a great thing to have.

As I am not a biologist, I am not sure if these are good examples, but as creationists are also not biologists I think it is a good thing to throw at them.

[KLIK]

Hi Wake,
the link below is to an article about bacterial increasing resistance to poison, (bacteria are popular due to the short life cycle, fruit flies about 10 days, oak trees [Quercus sp.] don't have acorns until about 90yr old so difficult to test out evolutionary theories)
Richard Dawkins in 'The Blind Watchmaker' also covers similar


http://www.corante.com/loom/archives...h_foretold.php

'.......But a Canadian evolutionary biologist named Graham Bell suspected that bacteria--and their evolutionary potential--might be more powerful than others thought. Michael Zasloff for one didn't think so. But as a good scientist, he was willing to put his hypothesis to the test. Remarkably, it failed.
The researchers began by exposing bacteria to low levels of antimicrobial peptides. They would then use a few of the survivors to start a new colony and then expose the bacteria to slightly higher levels of the poison. As they report in the Proceedings of the Royal Society of London, 30 out of 32 colonies evolved to be resistant to a full does of antimicrobial peptides. It took only about 600 generations for them to do the impossible. .....'

rgds KLK

[Ivan Viehoff]

Putting my pedant's hat on temporarily, I think people here are accepting the shorthand "evolution" meaning "the origin of species through evolution by natural selection", for which "the Darwinian theory" is a useful shorthand.

"Evolution" itself is a process, not a theory, as is "natural selection".

That natural selection will lead to evolution (in the short term) is one (lab-testable) theory, which even "creation scientists" will say they don't doubt. Once you acknowledge the role of genes in biology (itself "only" a theory, but a very solidly based one), it becomes very difficult to deny. The origin of species (in the long term) through evolution by natural selection is the full-blown Darwinian theory.

That said, one has to be clear about what are the alternative hypotheses which the Darwinian theory has successfully excluded. The main one that it excluded historically was the origin of species by Lamarckian evolution. http://en.wikipedia.org/wiki/Lamarckism (Contrariwise, Lamarckian evolution does seem to be a fairly good description of the evolution of knowledge itself.) People sometimes say that the Darwinian model is under threat from "punctuated equilibrium", but the reality is that such is within the scope of the Darwinian model, and these are just details of the practical operation. That (unsubstantiated and probably false) idea that the Darwinian process must be slow is not a necessity of the Darwinian theory, though because Darwin himself wrote it, many people suppose it is. I am not really aware of any other serious theory that has been proposed as an alternative to Darwinism, waiting to take over when the inconvenient evidence is unearthed. I suppose if some such substantially inconvenient scientific evidence should be unearthed, it will be back to the drawing board (compare "dark energy", being code for "something wrong with our present theories of the fundamental forces of nature"). Many people hypothesise the origin of species by magic (a general description, usually not adopted by those who propose specific versions of it), and suggest Darwinism should be capable of excluding it. But magic is not a testable theory, so no scientific theory is ever capable of excluding it; but by the same token there is no scientific mileage in it.

[Swift]

.
Are there examples of biological experiments where, let's say, Darwin's theory predicted the results?

As AndreH said, the development of antibiotic resistant bacteria is a continuing example of evolution in process. I would also highly recommend the wonderfully written book, "The Beak of the Finch", which describes the 20 years of work that Rosemary and Peter Grant have done studying the on-going evolution of finches on one island in the Galapagos. It also touches on similar research projects. And the current issue of American Scientist has an article about pupfish, a desert species, and how they evolved to fill very specific niches.

[aurora]

Why is germ theory still a theory?

Why is gravity still a theory?

Why is relativity still a theory?

[Ronald Brak]

I'll just mention that Darwin himself wrote about punctuated equilbrium, although he of course didn't call it that. I find that in North America people often seem to regard punctuated equilbrium as if it's a relatively new idea. I'm not sure why. (I realize you're not in North America, Ivan.)

[Lord Jubjub]

Reading this thread, I think this idea probably fits most scientific thought:

You have Facts (e.g. it takes so many seconds for an object to fall to the ground)
Laws explain Facts (e.g. f=ma)
Theories explain Laws (e.g. Newton's Theory of Gravitation)

[wake]

.

Uh oh.

The "pick up a string and it's attached to an elephant" & "The more you know, the more you know you don't know" factors are showing up.

But still, I feel much better and I can speak a little more knowledgeably the next time a "flat-earther" starts shooting his mouth off.

Thanks to all,

wake


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[Professor Mayhem]

No amount of validation changes a theory into a law. Scientific laws and scientific theories are two different things used for different purposes.

The scientific community isn't casting doubt on a theory by labeling it as such, and a scientific theory isn't some middle step were a scientific idea has to be milled about before graduating to scientific law.

Scientific theories are, above all, tools for scientific research. They more successful they are in making accurate predictions and framing scientific data, the more accepted they are. In other words, if they are useful and accurate, they stick.

[Click Ticker]

The scientific community isn't casting doubt on a theory by labeling it as such, and a scientific theory isn't some middle step were a scientific idea has to be milled about before graduating to scientific law.

This is something that falls far short in science education from my own anecdotal evidence. It's possible I misunderstood something - but I clearly recall our basic science classes teaching:

Step 1: Hypthesis
Step 2: Graduate to theory after testing
Step 3: Graduate to law after proving

I have come to understand otherwise after a bit of self study - but this is how many creationists think science works.

[Sean Clayden]

Progression is a natural phenomenon, evolution or progression its still the same, bigger stronger faster will continue............

[Noclevername]

Progression is a natural phenomenon, evolution or progression its still the same, bigger stronger faster will continue............

In evolution, sometimes smaller-slower-weaker is the survival strategy that works best. See Island Dwarfism.