Since Evolution can't be verified by the Scientific Method (namely experimentation) is it science or theory?

Question

Not looking for reactive responses, nor am I aiming to make people angry. I repect all points of view and this is just something I've been wondering about.

I'm asking this, because I was recently reading the definition of the scientific method in a science textbook, and part of this describes this method as "test with experiments". Since you can't test, or observe, cross-species evolution in an experiment, would that then make large-scale cross-species evolution only theory, and not science?

I understand that mutations and small-scale evolution can be observed (such as changes in fruit flies, moths, etc.) but the changes of one species into another can't be observed or recreated in experiments. Would this then render evolutionary as a theory unable to be verified by the scientific method?

Again, no reactive responses please. I'm just interested in learning.

Thanks.

Answer 1

Well it *is* science, but it's also a theory. Macroevolution is not something that we can test, no. Experiments that last thousands of years are not feasible.

I'm surprised at the vast number of people that seem to be unaware that this isn't something we can test, both on here and in general.

We can collect evidence even if we can't conduct true experiments on the topic. Most believe the evidence is overwhelming in favor of the theory of evolution.

Most current experiments on the subject are not aimed at disproving the theory itself, but small aspects of it. In other words we can look for evidence that two organisms have a common ancestor by comparative DNA sequencing. However the results only lead to varying levels of support for either hypothesis, they are not definitive.

Answer 2

There is no such thing as THE scientific method.
There is the experimental method, as you have
stated, and the comparative method. Many
sciences perform few or no experiments, but this does not make them unscientific. Astronomy was
one of the first sciences developed, but you don't
find scientists performing experiments on stars.
Geology, likewise, is a largely nonexperimental
science.

Evolution on a small scale not only can be, but
has been tested experimentally many times. New
species have been created frequently by breeders
usually in plants, which withstand such manipulation
better than animals do. Similar processes occur
naturally, as well.

Evolution of new species by natural selection alone
has not been tested by scientists, so far as I know,
but only because the process takes so long. The
fastest natural origin of a new species I have ever
heard of took 1000-1500 years. It has been
estimated that origin of a new species of mammal
may require a million years, though it's hard to
judge how accurate such an estimate might be.

Answer 3

It sort of is observed and experimented. Like you said, they have experimented in controlled environments and labs to prove that the processes of evolution work (ie natural selection and mutations). But it has also been observed in nature. For example, the TB bacteria. Or, ring species, like salamanders.

So really, it is experimented and observed. Now, no observation or experiment has been done in which one species evolved into a completely new one, but that just isn't plausible. Its the same as gravity, before space travel. Science knew that mass causes gravity, and the earth's gravity was real, before anyone ever sent anything into the sky to observe this on a large scale.

Answer 4

Evolution can and has been verified in laboratory tests. There have been numerous documented cases of new species emerging, in both animals and plants, as well as single-celled organisms. In addition, segregation of mating viability has been re-created in lab settings in populations of critters like fruit flies, which have even included selection for variation in phenotypic expressions (i.e. creation of big fly species and little fly species that select their own mates from the populations).

There is also a misconception on your part about 'only a theory'. All of science is built on theories. Laboratory exercises never 'prove' a theory, they can only support the predictions of a theory, or disprove the theory if the results of an experiment do not match the predictions. There is no higher level of science than the theory - theories do not graduate to laws if their predictions match experimental data - they simply remain as sound theories. Thus we have the theory of gravity, the theory of relativity, germ theory, and the theory of evolution - all supported by laboratory experimentation and observational data.

There is also a misconception that science only occurs in the laboratory. Experimentation and observational evidence can occur in other settings, and also provide evidence to support or disprove a theory depending upon how those observations fit with the predictions of the theory.

Most of evolutionary biology is, by necessity, a historical science. Just as there is no laboratory experiment that can determine what style of architecture was used by Ancient Egyptians, paleontologists must reconstruct fossils using their knowledge of anatomy, and geology. Fitting together the pieces of how life on Earth evolved requires looking at the patterns and distributions of various fossils, and their similarities and differences over time. Documenting these fossils, their anatomy, their chronological displacement, biogeographic distribution and ecological niches may not involve a lab coat and a controlled experiment, but it is still scientific, using techniques and tools developed through laboratory experimentation.

In many cases, it is much like the forensic reconstruction that occurs on shows like CSI or whatnot. There's no way to perform a controlled experiment to determine if Joe Blow shot Susie Q, but when you compare the blood spatters on the wall, the bullet in Susie's head that matches the rifling on the pistol found two miles away with Joe's fingerprints on them, the powder burns on his hands, the footprints that match the boots in Joe Blow's closet, the red-light camera that caught him driving away from Susie's house at about the same time that her liver temperature and progression of scavenging flies on her body indicate that she died at, then you have a pretty good, scientific set of evidence that matches with your theory that Joe Blow shot Susie Q.

Answer 5

Experimentation in the scientific method includes not only things like dissolving compunds in acid, but also things like archaeology, observation and the like.

It is, in fact, a very, very falsifyable theory (it has a lot of opportunities to be proven wrong) but it never is falsified. That's the very definition of a good theory.

Also, bear in mind that the scientific definition of a theory is "the best and most reasonable explanation for a set of evidence."

It's not a hypothesis....it's a theory.

Answer 6

Actually, the theory of evolution is verified every single day using the scientific method. But I'll get to that in a moment.

And I'll also refrain from reacting to your choice of "science or theory" as if they were two mutually incompatible things. *All* science is theory. The words "theory" does not mean "unscientific."

But let's address your specific question.

You talk about "cross-species evolution." If you mean, evolution of one species A into an *existing* species B (dogs evolving into cats), then there is no such thing, and this is NOT part of the theory of evolution. (I'm assuming you know this already ... that would be a pretty silly understanding of evolution ... but technically, that's what "cross-species evolution" would mean.)

If you mean the branching of a new species B from an old species A, then this IS part of the theory of evolution, and has been documented in nature, and shown by experiment in the lab. This is not called "cross-species evolution" but simply "speciation" ... the creation of new species.

In this case, all the scientists need to show is that, starting with a single species A, if two subpopulations get separated into two groups so they are not physically in contact to interbreed, and they are subjected to different environmental pressures, then within a few generations (as few as 30 or 40) the two groups can lose the ability to interbreed with each other. I.e. even if you put the two groups together, they will either fail to breed and produce offspring, or if they do produce offspring, they will be infertile. At that point these two groups are BY DEFINITION, two different species (they can't interbreed). You can call them species A and B (i.e. consider one the parent species, and the other a daughter species), or two new species B and C. But the important thing is that this has demonstrated speciation (there was once one species, now there are two species).

This experiment has been done, in the laboratory, using plants, fruit flies, house flies, apple maggot flies, flour beetles, worms, mosquitos, etc.

Second, scientists have documented cases in nature where a single species got introduced into an isolated environment, or an environment split into two naturally, and this resulted in a new species B that is no longer able to interbreed with its foundation species A. For example, rapid speciation of the Faeroe Island mouse withing 250 years of accidental introduction by humans, or the branching of five new species of cichlid fish in Lake Nagubago. (See source 2.)

Now, I'm sure you will object that these are small-scale speciation examples ... i.e. a fruit fly is just a fruit fly, and a cichlid fish is just a cichlid fish. But since you're talking about the scientific method, then you have to accept scientific terms. Two groups of fruit flies that cannot interbreed are BY DEFINITION two different species. Five groups of cichlid fish that cannot interbreed are BY DEFINITION five different species.

But also, you should not limit the "scientific method" to only *direct observation* (observations and experiments that can be done within the lifetime of a human observer). First, some things cannot be directly manipulated in an experiment because they are very large, very distant, or very old (like the sun, distant galazies, or evolution). And second some processes take more than a human lifespan to execute, but that does not mean that any theory about these processes is unscientific or does not use the "scientific method." If we can get evidence of these theories through *indirect observations*, these are fully scientific.

For example, we have never seen a star or a planet form, as this process can also take a million years or more ... but that does not reduce our confidence of how stars and planets form ... or the simple fact that they *do* form. We have knowledge of these processes by *indirect observations* of stars in various stages of formation today. We do not simply assume that because we cannot *directly* observe a star form within the lifetime of a human observer, that stars must therefore have been created instantaneously by God in their current form!

So *indirect observation* is also part of the scientific method.

The same applies to evolution.

- We cannot directly observe all the flu viruses in the world evolving into new strains. But the fact that we need a new flu shot every year is evidence by *indirect observation* that these viruses have in fact evolved to be resistant to last-year's flu shot.

- We cannot directly observe whales and dolphins evolving from land-dwelling ancestors (as those ancestors are long extinct). But the fact whales and dolphins have vestigial hip and leg bones is *indirect evidence* of that evolution. And even moreso, the fac that dolphin embryos go through a stage of development with visible leg buds.

- We cannot directly observe humans, chimps, and gorillas all evolving from the same ancestor (as that ancestor is long extinct). But the fact that humans have a muscle in the calf (the plantaris muscle) that is entirely useless, but is used by chimps and gorillas for grasping with the feet, is *indirect evidence* of evolution from that common ancestor. And even moreso, the many genes, proteins, and junk DNA which are molecule-for molecule identical between humans and chimps, but with *slight* differences from gorillas is *indirect evidence* of a closer link to chimps than we have to gorillas.

So we have both *direct evidence* of speciation, and a MOUNTAIN of *indirect evidence* of common ancestry in all existing animals.

These *together* constitute the evidence of evolution using the scientific method.

Answer 7

Evolution is testable. Every time we discover a new species it is a potential test of evolution. If we find a species that doesn't conform to the theory then we either have to reject it or modify it. So far all we have done is modify it. There have been no species that have been found that cause us to reject it.

Fossils are the primary way to test "macro" evolution and what I said above still stands for fossils.

Answer 8

Proof 1:

http://en.wikipedia.org/wiki/Miller-Urey_experiment