Talk:Evolution/FactvsTheory

Distinctions between theory and fact

 * ''Further information: Scientific Theory
 * See also: Theory vs. Fact

The Terminology of Science
Scientists use many specialized terms, frequently incorporating terminology that may have different meanings to the lay-person. In defining "fact" and "theory", scientists ascribe to them very distinct meanings:


 * In science, a fact is an observation or a piece of data. A "fact" in science is a measurement or some evidence or the result of an experiment. For example, there are many observations of gravity and measurements of gravity. Every time an apple is dropped and it falls, an observation of gravity has been made. Gravity is measured every time something is weighed. So gravity can be described by scientists as a "fact". This is because there is a collection of gravity observations that need to be explained. And observations are "facts" in scientific language.


 * Theories in science are different from facts. "Theories" in science are the description of the coherent framework into which the observable data fit. There have been many "theories" that attempt to explain the "fact" of "gravity". That is, scientists ask what is gravity, and what causes it? Scientists try to develop a model to explain gravity; this model is called a "theory" of gravity. Predictions can be made based on this "theory" of gravity. There have been many explanations of gravity that qualify as a Theory of Gravity over the centuries; Aristotle's theory of gravity, Galileo's theory of gravity, Newton's theory of gravity and now Einstein's theory of gravity. So gravity is also a "theory". In no case did gravity simply disappear when a new theory was created, only the explanation underlying gravity was refined and improved.

Carefully examining these two descriptions of the words "fact" and "theory" in a scientific context, reveals a source of confusion when discussing gravity. Gravity is referred to as both a "fact" and a "theory". Gravity is a "fact" because it has been observed, and observations are "facts" in scientific language. Gravity is also the name of the explanation for this "fact" and other evidence, or "facts". And scientific explanations are called "theories" in the language of science. So gravity is also a "theory", as well as a "fact".

The word "gravity" has been assigned to two different things, a "theory" and a "fact". It might appear confusing and disenguous to refer to gravity as both a "theory" and a "fact", but it is accurate. Gravity is an observable "fact". How and why gravity exerts its force onto objects is the subject of a Theory of Gravity. A Theory of Gravity is subject to rigorous scientific study, and it may change. It is common to refer to the most widely accepted "theory" of gravity as The Theory of Gravity, although of course it is just one of several. The validity of the statement that gravity exists remains unchanged, no matter what "theory" is most widely accepted, or even if no "theory" exists at that moment.

Scientific terminology applied to evolution
"Fact" and "theory" can be applied to evolution, just as it is to gravity. This terminology has been used to dispute the validity of Evolution, which results from a misunderstanding of how those terms are applied to Evolution.

In the study of biological species, the "facts" include fossils and measurements of these fossils. The location of a fossil is an example of a "fact" (using the scientific meaning of the word "fact"). The age of particular fossils is also a fact. In species that rapidly reproduce, for example fruit flies, the process of evolutionary change has been observed in the laboratory. The observation of fruit fly populations changing character is also an example of a "fact", using the scientific meaning of the word "fact". So evolution is a "fact", at least using the scientific meaning of the word "fact". These "facts" need an explanation, just like the observations of gravity did.

In biology, there have been many attempts to explain these observations over the years. Lamarckism, Transmutationism and Orthogenesis are all nonDarwinian "theories" (in the scientific sense of the word "theory") that attempt to explain the observations of species and fossils and other evidence. However, the explanation for all these data or "facts" that is currently most accepted by scientists is called the Theory of Evolution. The "theory" of evolution is a model that explains the vast majority of the data, or evidence, that exist. So evolution is not only a "fact" but a "theory", just as gravity is both a "fact" and a "theory".

This confusion between "fact" and "theory" in the study of evolution was explored in a well-known quote by paleontologist Stephen Jay Gould:
 * "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 do not go away when scientists debate rival theories to explain them. Einstein's theory of gravitation replaced Newton's, but apples did not suspend themselves in mid-air, pending the outcome. And humans evolved from ape-like ancestors whether they did so by Darwin's proposed mechanism or by some other yet to be discovered."

Related concepts

 * Speculative or conjectural explanations are called hypotheses. Well-tested explanations are called theories.


 * "Theories" are not "true" in science, at least in the regular sense of the word "true". "True" "theories" only are "confirmed to such a degree that it would be perverse to withhold provisional assent."


 * "Proof" of a theory does not exist in science. Proof only exists in mathematics.


 * A scientific law is a concept related to a scientific theory. Very well-established "theories" that rely on a simple principle are often called scientific "laws". For example, it is common to encounter reference to the "law of natural selection" or the "laws of evolution."

Table
These are some experiments with tables and colors. What do you think would look best and be most effective?--Filll 17:31, 14 December 2006 (UTC)


 * I like these tables. I prefer simpler colors, but that's me.OrangeMarlin 18:50, 14 December 2006 (UTC)


 * I like the white on blue the best. OrangeMarlin 19:48, 14 December 2006 (UTC)


 * I must admit the table is a simple way to convey the message.GetAgrippa 21:56, 14 December 2006 (UTC)


 * I'd prefer less "pure" colours than the top dark blue, but otherwise like the blue. Adam Cuerden talk 04:23, 15 December 2006 (UTC)

I toned the colors down and launched this as its own page. I also replaced the corresponding sections of the evolution and controversy articles with an abbreviated version of this material, with links to a longer article which is basically what is on this page.--Filll 08:55, 15 December 2006 (UTC)