Is Evolution a Fact or Theory? Understanding the Scientific Perspective

[Dooga Blackrazor]

Wikipedia states that evolution is fact; however, how evolution works is theory. Is this true?

A friend of mine doesn't believe in evolution, and I have been trying to convince him. Is there a scientific dictionary that will give me an answer?

 

[cronxeh]

Theory is as best and as reliable as a fact gets. When there is evidence to contrary of evolution being false, then it is no longer a theory, but rather a hypothesis.

No matter what you tell your friends its not going to make sense to him. He should take 2 courses in Biology at college/university level. In the event he has no desire to understand the matter, you in turn should not waste your time trying to persuade such an individual of enormous magnitude of ignorance that the light of day itself can not escape their presence.

 

[Dooga Blackrazor]

Alright, thanks.

 

[moose]

The part that animals change over time is a fact. We have obviously seen this happen.

 

[selfAdjoint]

Evidence for evolution

See the http://www.talkorigins.org/faqs/comdesc/" essay at talk.origins.archive. They can experimentally make bacteria evolve. Many plant species are shown to evolve, with detailed genetic confirmation. And fish in an African lake are in the process of speciating. The point is not that animals can change with time but that species arise due to the changes. And this is a fact, according to the evidence brought forth.

That the mechanism for this speciation is variation and natural selection is a theory, but this is a theory in the same sense that relativity and quantum mechanics are. The detailed mechanisms are supported by the experiments.

For what the public calls a theory, scientists use other words, like hypothesis and conjecture.

 

[Pengwuino]

If he's like me and can't handle anything that doesn't have a thousand and one formulas related to it, don't bother.

 

[Dooga Blackrazor]

Thanks again. I am curious because my friend asked me why all species don't evolve. I said I wasn't sure that was true, but, if it was, that doesn't discredit the theory of evolution. Do all species evolve?

 

[iansmith]

Thanks again. I am curious because my friend asked me why all species don't evolve. I said I wasn't sure that was true, but, if it was, that doesn't discredit the theory of evolution. Do all species evolve?

All species evolve but not all evolution is perceivable in human life spam.

Species with smaller generation time will appear to evolve quicker. The best example are bacteria vs. human. Human have a 20-30 years generation whereas bacteria have 20-30 minutes generation time. So over 20-30 years a specie of bacteria will accumulate more genetic variation than a human.

Human population in Europe have evolved in the last 800 years. The last major black plague epidemic was a bit less than 700 years ago. This epidemic cause the a bottleneck, a well characterized mechanism of evolution, in the human population in Europe. A gene called CCR5-delta32 is though to have been selected during that period of time because of the epidemic. (http://www.ncbi.nlm.nih.gov/entrez/...d&dopt=Abstract&list_uids=15715976&query_hl=4)
However, recent studies may point that the CCR5-delta32 may not have been selected during the middle ages but that it evolve through neutral evolution mechanism (http://www.ncbi.nlm.nih.gov/entrez/...d&dopt=Abstract&list_uids=16248677&query_hl=1)

 

[Livingod]

If your friend doesn't believe in evolution because he believes in god, i have something to say:

Some guy (I'll post his name afer I remember it) did some experiment that simulated the conditions of Earth 4 billion or something years ago. With the amount of heat and lightning of that time, he saw that amino acids were forming in the soil. One theory of evolution is that organisms evolved from simpler organisms which were made of amino acid that came out of the ground. Now, in the Koran (and I believe this is in the Bible too) it says that man was made of soil, or man came from the earth, something like that. So, these two theories (well, one theory, one holy scripture) pretty much agree.

Now, I learned of this experiment from a Bio textbok in junior high while studying for the Regents, so I don't have the textbook at my disposal right now, but I will post the missing information as soon as I do.

If your friend believes in god, this might help.

 

[iansmith]

Some guy (I'll post his name afer I remember it) did some experiment that simulated the conditions of Earth 4 billion or something years ago. With the amount of heat and lightning of that time, he saw that amino acids were forming in the soil. One theory of evolution is that organisms evolved from simpler organisms which were made of amino acid that came out of the ground. Now, in the Koran (and I believe this is in the Bible too) it says that man was made of soil, or man came from the earth, something like that. So, these two theories (well, one theory, one holy scripture) pretty much agree.

That is not evolution because evolution does not deal with the origin of life. Abiogenesis is one of the theories that deal with the origin of life.
http://en.wikipedia.org/wiki/Origin_of_life

 

[adrenaline]

Your friend is totally hung up on the vernacular meaning of "theory".
This is what it boils down to.
The existence of biological evolution is a fact.
We are less certain of the exact mechanism of evolution so there are many theories about its mechanism.
In science, theories are structures of ideas that explain and interpret facts.
Facts don't go away.
Einstein's theory of gravitation replaced Newton's in this century, but the effects of gravity did not go away.

 

[Moonbear]

I'm so happy to wander into a thread on evolution and see so many people understanding it and explaining it properly. The only thing I would disagree with is the suggestion to not bother. I think you should bother, but I also think you're taking the right approach to make sure your own information is correct first. What you shouldn't do is take it personally if he doesn't accept the explanation. Don't push or argue, just explain patiently.

Also, to Livingod, as iansmith pointed out, abiogenesis is not part of the theory of evolution. The theory of evolution describes the processes that happen after life was already formed. Sometimes clearing up this misconception alone can open up someone's mind to listening to the science, because it is the origin of life that really bothers them and contradicts their religious beliefs. Science does not provide an answer as to how life originated; it is only conjecture at this time.

 

[Livingod]

Im saying that the Holy Books support abiogenesis and evolution, thus enabling man to come out of the earth, in a sense.

 

[SGT]

As Adrenaline pointed, Newtonian and Einstenian theories of gravitation are only theories. Ask your fundie friend to jump from the 20th floor window, since theories are not to be believed.

 

[jim mcnamara]

Ultimately it makes no difference.

To believe essentially means to accept something as fact without proof.

Fundamental Christians need to validate their point of view. So they resort to finding a proof of something they believe in - after the fact.
Politicans do this all the time. It's normal human behavior.

The reason for validating every statement in the Bible is very simple:

If the creation of the world, as it exists in Genesis, is a story and is not an absolute fact, it then means that part (or parts) of the Bible are stories, and are not absolute truths. Therefore, it now becomes possible that other parts of the Bible may be taken as something other than incontrovertible fact.

In other words, you are wasting your time trying to convince him/her otherwise.

See:
http://www.cnn.com/2005/EDUCATION/11/08/evolution.debate.ap/index.html for folks who put belief at the top of their agenda.

See this for people who try to reconcile Christian belief and science:

http://www.lawrence.com/news/2005/dec/05/god_science_and_kooky_kansans_who_love_them_both/

If you really weant to try logic: www.pandasthumb.org

 

[cronxeh]

In addition, the board rewrote the definition of science, so that it is no longer limited to the search for natural explanations of phenomena.

Hmm.. this is pathetic

 

[jim mcnamara]

(IMO) ----
the Fundamental Christians want a return to something like Scholasticism -where all secular life revolves around the church.

Also, they have a disproportionate voice in everday politics because they are expected to tithe - contribute 10% of their income - to the Church.
Apparently there are about 30 million Evangleical Christians in the US, about 10% of the population. Their presence in the media exceeds
their true numbers by a vast difference, compared with other kinds of "directed" media.

This means relatively small congregations to have very large politcal impact. What the congregation tithes is supposed to go for good works, and the folks on the receiving end of the money deem purchasing and supporting Christian broadcasting companies good works.

Urban areas have a minimum of 2 UHF Christian stations, and there are several Christian networks that are on most cable outlets.

 

[Dooga Blackrazor]

For those of you wondering (if this helps), my friend is Muslim.

 

[selfAdjoint]

As I understand it, the Muslim tradition for the past 500 years or so has been to reject regular rational explanations of how the world works (cosmology as well as evolution) because that limits the power of God to do whatever he wants. Newton rejected this belief, saying that the regularities in nature - planets moving in orbits and so on - ARE what God wants. That every time a stone falls under gravity, that's a specific divine miracle. You could make the same argument about evolution.

 

[pattylou]

There is some discussion as to whether Evolution is a theory or a fact on this thread (on a different discussion forum):

http://www.elmhurstsolutions.co.uk/cgi-bin/yabb2/YaBB.pl?num=1130230630/0

Ignore most of the first page of posts; the theory/fact/etc discussion develops somewhere on page 2 (around post #17), if I recall correctly.

 

[NutriGrainKiller]

Wikipedia states that evolution is fact; however, how evolution works is theory. Is this true?
A friend of mine doesn't believe in evolution, and I have been trying to convince him. Is there a scientific dictionary that will give me an answer?

evolution is as close to a fact as we can get. evolution is a scientific theory. This is not the same type of theory say a detective would make at a crime scene. Scientific theory is very, very well supported by massive amounts of evidence. Debating whether evolution is true or not is like debating whether or not gravity exists.

By denying evolution as a fact, your friend is going against every bit of scientific integrity the world has strived for since the beginning of our era. I've heard all the best arguments from even some of the most persuasive defenders of intelligent design trying to ditch evolution as pishposh. In every case, their "proof" of creationism is lack of evidence for evolution. What they call lack of evidence, I call lack of knowledge. I went to a evolution vs intelligent design debate (i.e. crusaders for christ brainwashing the student body with a one sided lecture) fairly recently and the speaker was very uneducation on the science of biology. In fact, he went as far as to say he's more qualified to lecture on ID because he was an engineer, and engineers design things ("so does god"), while biologists don't. The most rediculous thing he said had to do with spontaneous generation - it was the backbone for his entire argument. What he failed to mention, however, was that spontaneous generation was disproved three centuries ago by a man named Lous Pasteur. I hate how these guys say they "prove" ID is true and evolution is false due to lack of evidence.

 

[Phobos]

Ultimately it makes no difference.

If the person is a deep-seated True Believer, then yeah, no amount of argument will likely ever be convincing as it would require a major worldview shift. But perhaps this person is still exploring different ideas or is sympathic to building bridges between science and religion. Or, at the very least, confronting such debates (in general) puts the information out there in front of people who are still on the fence. Without this, you get school boards full of creationists.

 

[Livingod]

Where is your friend from, and what sect of islam is he/she from? Maybe I can help a lot.

 

[Renge Ishyo]

The idea that organisms change over time should not surprise your friend as *everything* in nature has changed over time. That is not where the debate over Evolution arises. It arises once we consider the mechanisms that cause evolution to occur. Is evolution a purposeful process hard wired into our DNA, and therefore, perhaps it is handed down to us by a "higher power"? Or is it just the net result of a large accumulation of changes (random mutations?) that have occurred with organisms over time?

There isn't enough evidence at the present to answer either question with any sort of confidence that you are correct. Meaning that I am confident I can take the evidence available on either side and argue both cases effectively (I would have a much harder time for example trying to argue against the existence of gravity, because it is supported by DIRECT experimental evidence unlike many aspects of the theory of evolution that I can pick on). The people that do answer such questions usually do so on the basis of political affiliation, and this not only limits their ability to investigate into the phenomenon even further but it clouds their judgement. The real answer is we know that change is occurring (the facts support the idea that DNA is not a static thing but that it changes and gets modified as it is passed down from parent to offspring), but we cannot say conclusively at the moment "why" this is occurring (or has occurred). We have only recently mapped the genetic code, it will be awhile before (if) we can fully understand how it works.

 

[fileen]

perhaps you are offending your friend. this battle between god and science rages continuously, and yet I personally feel that it will never be ended, there is no evidence of god, and yet there is no evidence of no god. it is not right to tell a person that what they believe is wrong. the moment you suggest it they shut themselves off to you. this is only natural in y oppinion. pushing will not help you. perhaps you simply need to find a neutral ground. a friend of mine is a very firm believer in god, but he also understands and respects science. it seems impossible but if you don't get into the little things, if you stop arguing and challenging and you look at it most fundamentally they can co-exist. it is far too extensive and complicated to get into here but the big bang could have been motivated by god. if not god then what other energy. no one yet has given me proof of another that initiated it. I don't believe in god but I get along great with dave because we can respect each others believes and both of us are able to admit that there is no evidence either way.
what I am trying to say and perhaps not describing appropriately is that maybe before you discuss things like evlution you should make it clear that you are not in any way attempting to challenge your friends beliefs even if you do not share them.

 

[Mk]

All species evolve but not all evolution is perceivable in human life spam.
Species with smaller generation time will appear to evolve quicker. The best example are bacteria vs. human. Human have a 20-30 years generation whereas bacteria have 20-30 minutes generation time. So over 20-30 years a specie of bacteria will accumulate more genetic variation than a human.

Also, from Jan 06 issue of Science,

A favorite, if unlikely, subject for evolutionary studies is the
small fish called the stickleback. Repeatedly, sticklebacks have
moved from the sea into fresh water. When that happens, the fish
shed the rather heavy armor plates that protect them from marine
predators, freeing themselves to enjoy la dolce vita fresca. New species have been generated in each invasion,
always in the same way: by rapid evolutionary selection of the same rare and ancient gene.

and also, another quote

This year field biologists recorded compelling examples of that process, some of which featured surprisingly rapid evolution in organisms' shape and behavior. For example, birds called European blackcaps sharing breeding grounds in southern Germany and Austria are going their own ways—literally and figuratively. Sightings over the decades have shown that ever more of these warblers migrate to northerly
grounds in the winter rather than heading south. Isotopic data revealed that northerly
migrants reach the common breeding ground earlier and mate with one another
before southerly migrants arrive. This difference in timing may one day drive the two populations to become two species. Two races of European corn borers sharing
the same field may also be splitting up. The caterpillars have come to prefer different plants as they grow—one sticks to corn, and the other eats hops and mugwort—and they emit different pheromones, ensuring that they attract only their own kind. Biologists have also predicted that these kinds of behavioral traits may keep incipient species separate even when geographically isolated populations somehow wind up back in the same place. Again, examples have been few. But this year, researchers found that simple differences in male wing color, plus rapid changes in the numbers of chromosomes, were enough to maintain separate identities in reunited species of butterflies, and that Hawaiian crickets needed only unique songs to stay separate. In each case, the number of species observed today suggests that these traits have also led to rapid speciation, at a rate previously seen only in African cichlids.
Other researchers have looked within animals' genomes to analyze adaptation at the
genetic level. In various places in the Northern Hemisphere, for example, marine stickleback fish were scattered among landlocked lakes as the last Ice Age ended. Today, their descendants have evolved into dozens of different species, but each has independently lost the armor plates needed for protection from marine predators. Researchers expected that the gene responsible would vary from lake to lake. Instead, they found that each group of stranded sticklebacks had lost its armor by the same mechanism: a rare DNA defect affecting a signaling molecule involved in the development of dermal bones and teeth. That single preexisting variant—rare in the open ocean—allowed the fish to adapt rapidly to a new environment.

 

[Rade]

Wikipedia states that evolution is fact; however, how evolution works is theory. Is this true?
A friend of mine doesn't believe in evolution, and I have been trying to convince him. Is there a scientific dictionary that will give me an answer?

You may wish to buy your friend the following book, an excellent introduction to his question: "Evolution vs. Creationism", By Eugenie C. Scott. 2004. University of California Press. Dr. Scott provides a nice discussion about the differences between facts, hypotheses, laws, theories, which she presents in this order as the "method" of science. "Evolution" (change in gene frequencies over time) is a fact. The most important theory of how evolution works is called "natural selection" (e.g., the non-random reproduction of genotypes in a population). Important to remember, individuals do not evolve, populations (lots of breeding individuals) evolve. Sometimes, rarely, the evolutionary process results in formation of new species, but more common the population and species progress toward a state of non-existence (e.g., extinction).