Theory of Evolution

[Steve K]

I was reading Randi's website, and someone had written in to him saying that the theory of evolution was a cousin of the theory of gravity. By cousin, I assume the author meant equally well established.

My question is -- (And I'm no creationist) -- Is the theory of evolution really a scientific theory at all? My understanding of the scientific method is that theories are the result of experiments which can be replicated.

Now I can construct and execute an experiment to test the theory of gravity, but there is no way that I know of to construct or replicate a test for the theory of evolution.

Thoughts?

- Steve

[Late_Cretaceous]

Not all science requires experimentation.

What is required for science is; observation and prediction making. Laboratory experiments are handy for making observations in a controlled manner. However, what happens in a lab does not always translate to the outside world, so laboratory analysis is riddled with bias and error to begin with (these can usually be accounted for, but take up an inordinate amount of time).

Also, how do you do experiments for astronomy? Nobody dismisses astronomy as being non scientific.

The theory of evolution was originally proposed to explain certain observations. Most notably, biogeography. Why is Australia nearly deviod of placental mammals, and why is the rest of the world nearly devoid of marsupials?

It was also based on the observation that organisms produce many offspring, but only a few live to adulthood. For example, a fish lays thousands of eggs over her lifetime, in a stable population this means that only 2 live to adulthood and go on to reproduce themselves. What makes those 2 so special, and lucky over all their siblings. Hence the concept of Natural Selection.

Evolutionary theory made numerous predictions, among them are;

1. That there would be a mechanism for passing traits on from one generation to another.

2. That there would be a mechanism for creating change in these traits that could give an organism an advantage for survival.

3. That there should be a varying degree of relatedness among organisms. That any given organism should be more closely related to some organisms then others.

4. That evidence for the history of evolution could be found in the fossil record (very few well studied fossils were known at the time).

So, did these predictions come true?
You bet they did, and they continue to do so today.
In fact nothing has come to light to falsify any of these predicitons (remember, no scientific theory can ever be proven, but all can potentially be falsified).

#1. Mendel found that traits are indeed passed on from one generation to another, and can even appear to skip generations. This turned out to be verified by the discovery of DNA. DNA is a self replicating molecule that carries genes for all the traits of an organism - all of which are inherited from the parents.

#2. We are not carbon copies of our parents. Mutations can and do occur. Most are fatal, but so what you make a few million sper and a few are defective. HOw many pregancies abort early on because of mutations. The key is that you take hundreds of turns to try and reproduce in order to get only one sucessful offspring anwyas. Then there are those few mutations which are benificial. Like the mutation that occured in a species of bacteria allowing it to digest nylon (a whole new food source, and no competition).

#3. A horse looks a hell of a lot like a zebra, and very little like a turtle. Well guess what, DNA demonstrates this nicely too. Genetic studies have verified that certain organisms are very closely related, while others are not.

#4. The fossil record. Kangaroos are found only in Australia, and so are their fossils. No fossilized Kangaroo has been found in Canada. Lemur only occur in Madagasgar, and so do their fossils.
Also, we do not find whales in the Jurassic, or rabbits in the cambrain either.



ANd that only scratches the surface.

[God Fearing Atheist]

What Late said.

"Experiments" and "testing" need not always be done in a lab. A theory makes predictions, and its these predictions we confirm or refute by experimentation, wherever its done.

-GFA

[Undercurrent]

Originally posted by Steve K
Now I can construct and execute an experiment to test the theory of gravity...

Not really. Sure we can do some ball-dropping and satellite-launching, but we certainly can't test the theory of gravity through controlled experiment in the regimes of very large or very small masses. If "controlled experiment" was th sum total of what could be done to justify a theory, one would be hard pressed to justfy believing the theory of gravity holds true for galaxies and ping-pong balls.

[Shadowy Man]

Originally posted by Undercurrent
If "controlled experiment" was th sum total of what could be done to justify a theory, one would be hard pressed to justfy believing the theory of gravity holds true for galaxies and ping-pong balls.

In fact, the evidence suggests that it doesn't!! :eek:

[sodium]

Originally posted by Steve K
My question is -- (And I'm no creationist) -- Is the theory of evolution really a scientific theory at all? My understanding of the scientific method is that theories are the result of experiments which can be replicated.


We can repeat experiments providing evidence for evolution. Biologists can look at DNA, or go and see the fossil record, or use radiometric dating.

Of course, you can argue that it would be better if we could do an experiment where we could actually see the evolution of all life occur, and repeat that. But you can't always do the experiments you want. As has been pointed out, there are many experiments we might like to do in support of the gravity theory, but which we are unable to do.

I think the idea of replication is meant to counter ideas like my Lead-to-Gold Theory. My theory is that a sufficiently virtuous alchemist can transform lead to gold with the help of a Philosopher's Stone. And this is what I claim I've done. Can't replicate my results? Well, I guess you're not virtuous enough.

[Will I Am]

Is the theory of evolution really a scientific theory at all? My understanding of the scientific method is that theories are the result of experiments which can be replicated.

Steve, that idea of what Science is, is flat-out wrong. But it is what we teach our kids in school. Because it's simple.


The obvious fact is that much of Science is not based on what is commonly taught as "the" scientific method.

There are many scientific methods.

But archaeologists, astronomers, evolutionists… cannot run "experiments" in the conventional fashion.

Don't get tied up in definitions.

It's simple: "I think this happens because of this". <- is Science.

And as far as I know, "Evolution" is unique in the history of Science in that it has not one (single) competing theory. None.

I'll say that again: Evolutionn is 100% unchallenged. Scientifically.

(That doesn't mean its correct, (it may not be) but it dones mean it's pretty interesting).

[sakrilege]

From the National Academy of Sciences, Science and Creationism (http://bob.nap.edu/readingroom/books/creationism/introduction.html) Theory: In science, a well-substantiated explanation of some aspect of the natural world that can incorporate facts, laws, inferences, and tested hypotheses.

[RTS]

From Evolution is a Fact and a Theory (http://www.talkorigins.org/faqs/evolution-fact.html)

When non-biologists talk about biological evolution they often confuse two different aspects of the definition. Biologists consider the existence of biological evolution to be a fact. It can be demonstrated today and the historical evidence for its occurrence in the past is overwhelming. However, biologists readily admit that they are less certain of the exact mechanism of evolution; there are several theories of the mechanism of evolution.

Evolution is, like gravity, both a fact and a theory. The fact part is that life changes, over time, in ways we can observe from evidence. The theory of evolution attempts to explain the observed facts -- WHY and HOW does life change over time? The challenge is to derive theories that (1) explain all known observations; and (2) make predictions future observations can support or refute.

From - Stephen J. Gould, " Evolution as Fact and Theory"; Discover, May 1981"

[paraphrased]Well evolution is a theory. It is also a fact. And facts and theories are different things, not rungs in a hierarchy of increasing certainty. Facts are the world's data. Theories are structures of ideas that explain and interpret facts. Facts don't go away when scientists debate rival theories to explain them. Whether creationists like it or not, all humans evolved from a common ape-like ancestor whether they did so by Darwin's proposed mechanism or by some other mechanism yet to be discovered.

The FACT of evolution is written in the geological record in exquisite detail. Nobody who pays the slightest attention to the facts can avoid the conclusion that life has changed over the course of time. Anyone who denies this simply has no business being part of a discussion of evolution, since they have no idea what evolution IS.

Gould: Moreover, "fact" doesn't mean "absolute certainty"; there ain't no such animal in this exciting and complex world. The final proofs of logic and mathematics flow deductively from stated premises and achieve certainty only because they are NOT about the empirical world. Evolutionists make no claim for perpetual truth, though creationists often do (and then attack us falsely for a style of argument that they themselves favor). In science "fact" can only mean "confirmed to such a degree that it would be perverse to withhold provisional consent." I suppose that apples might start to rise tomorrow, but the possibility does not merit equal time in physics classrooms.

Evolutionists have been very clear about this distinction of fact and theory from the very beginning, if only because we have always acknowledged how far we are from completely understanding the mechanisms (theory) by which evolution (fact) occurred. Darwin continually emphasized the difference between his two great and separate accomplishments: establishing the fact of evolution, and proposing a theory--natural selection--to explain the mechanism of evolution.

[Evolutionist]

you know RTS- that post looks almost exactaly like the evolution is fact and theory (http://www.talkorigins.org/faqs/evolution-fact.html) page on talk origins.... odd isn't it?

[RTS]

Standing on the shoulders of giants.

[Friar Bellows]

Originally posted by RTS
Standing on the shoulders of giants.

But can you see any farther? :p

[RTS]

My understanding of evolution continues to reach new heights, and where knowledge is concerned, my hyperopia increases daily. I am currently studying 'structuralism and fuctionalism in evolution' and Sir Francis Galton, a contemporary of Darwin.

Galton suggested an image for what are now termed "evolutionary constraints". He visualized a polyhedron, a solid object with multiple flat faces. In Galton's view, evolution was a process of "facet flipping", whereby an organism (really, a species) sat on a flat face of the polyhedron, in a stable configuration. On rare occasion (perhaps for adaptational reasons, perhaps not) the polyhedron would roll into an adjacent face, where it would again be stable. The result was a new species.

This viewpoint was generally anti-Darwinian in nature, for several reasons:

1) As distinct from Darwin's view of insensibly tiny changes gradually piling up over long periods of time, Galton's view had new species occurring fairly suddenly by comparison.

2) As distinct from Darwin's view of every species being in constant (but extremely slow) transition, Galton had species being static for very long periods.

3) As distinct from Darwin's view that evolution is inherently nondirectional, and given environmental reward could "move" in any direction, Galton had his polyhedron only able to flip to adjacent facets. If such a flip were possible and useful, the species would evolve into something different and more viable. If it were not possible, the species would die out as the environment changed.

4) As distinct from Darwin's uniformitarianism (where the environment was essentially constant, or changed exceedingly slowly over geologic ages), Galton pictured what Darwin considered "catastrophic" environmental changes. For example, ice ages.

Galton's view led to a school of evolutionary thought today called by various terms including "structuralist", "formalist", and "internalist." This school is by nature permanently in conflict with the strictly Darwinian school of adaptationalist (also known as "functionalist.")

It should be noted that the functionalist and the structuralist agree that all life forms today evolved from single cells at some time in the distant past. The disagreement, as always, is about the method. Gradually, these viewpoints are converging, again for many reasons.

The debates between evolutionary viewpoints, the history of those viewpoints, their relationship to the evidence and observations, is a deep and fascinating topic to me.

[Wyz_sub10]

I think we've reached a point where this should be in E/C

[caravelair]

Originally posted by Shadowy Man
In fact, the evidence suggests that it doesn't!! :eek:

are you referring to the problem that is usually explained using dark matter?

[Shadowy Man]

Originally posted by caravelair
are you referring to the problem that is usually explained using dark matter?

yes.

[Leli]

Well, Isn't the "law" of gravity being shown to be less of a law and more of a guideline?
Hey, did Isaac Newton allow for superconductors, incidentally?Someone fill me in...(I never took physics in University, actually I've always been the biology kind of girl, but the more I want to know about how things work the more I need to learn about Chemistry and physics and the "interconnectedness of all things").

[RED DAVE]

CHECK THIS OUT:

Evolution Is a Fact and a Theory (http://www.talkorigins.org/faqs/evolution-fact.html)

RED DAVE

[MrDarwin]

Originally posted by Steve K
My question is -- (And I'm no creationist) -- Is the theory of evolution really a scientific theory at all? My understanding of the scientific method is that theories are the result of experiments which can be replicated.

Now I can construct and execute an experiment to test the theory of gravity, but there is no way that I know of to construct or replicate a test for the theory of evolution.

A very common misunderstanding (or misrepresentation, depending on how cynical you are) about science by creationists and others who don't really know what they're talking about. It is the scientific methodology that must be able to be replicated--subtle difference. An important cornerstone of science is that a scientist will say exactly what he did and exactly how he did it, so other scientists can come along and evaluate and test his or her methodology. Thus a good scientific paper will always have a "materials and methods" section, so other scientists who are so inclined can critically examine the methodology and find it sound or faulty, and repeat it if they so desire, to test it to support or falsify the original researcher's conclusions. The best scientific papers will make specific predictions about observations or tests that haven't been performed yet based on their hypothesis, and say exactly what should be expected if their hypothesis is correct.. When that or another scientist tests those predictions, that is an experiment.

"Experiment" is actually a very broad term (defined artificially narrowly by people who don't understand science) and includes pretty much everything described in the "materials and methods" section of a paper. "Materials" can be living organisms, rocks, fossils, genes, etc. "Methodology" can include things like digging up and dating fossils (if you only find a certain species of fossil in a certain age of rock, you are replicating somebody else's "experiment"); observing and describing a fossil organism (if you examine the same set of fossils, or fossils of the same creature, and prove that a previous researcher has misinterpreted a particular structure, you are falsifying their conclusions); sequencing and comparing the same gene or genes in a set of related organisms; etc. etc. etc.