FALSIFIABILITY
and the difference between
FALSIFIABLE AND FALSIFIED

Whenever one uses the scientific method of inquiry, guesses are made about possible answers to a problem. These guesses are called hypotheses. But to be scientific, there must always be two hypotheses made simultaneously: the hypothesis and the null hypothesis. Suppose the guess is that smoking causes lung cancer. To be scientific a null hypothesis must also be made at the same time, that smoking does not cause lung cancer. Then an experiment is undertaken, that is additional evidence is gathered which will test the two opposing hypotheses simultaneously. What is being said here is that the idea of smoking causing lung cancer is falsifiable. In other words, it is possible to demonstrate on the basis of the evidence that that idea or hypothesis is incorrect and therefore falsified.

However, if the evidence gathered rejects the null hypothesis and supports the hypothesis, then the idea that smoking causes cancer is NOT falsified. An hypothesis does not have to be falsified to be scientific, but it must be testable (falsifiable). People must understand that there is a very clear distinction between "falsifiable" and "falsified".

Evolutionary Biology is the study of genetic changes in populations, thus a study cannot be falsified because it simply exists as does chemistry, physics or astronomy. Evolution is a term that applies to a whole host of hypotheses and theories concerning genetic changes in populations and the results of those changes through time. All hypotheses and theories of evolution are testable and thus falsifiable by either direct or indirect evidence. There are a number of evolutionary hypotheses that have been falsified and as a result have been rejected by the scientific community as supported by the evidence. Such hypotheses as Lamarkianism, mutationism and saltationism have not been supported by the evidence and thus have been falsified.

However, other hypotheses that are falsifiable have not been falsified, but have been supported by abundant evidence. Natural selection, punctuated equilibrium and allopatric speciation have been supported by the evidence and have NOT been falsified even though these ideas are falsifiable. Perhaps in the coming decades and centuries of research these ideas will never be falsified, but nevertheless will always remain testable and thus falsifiable and scientific.

Science is not out to prove anything! The purpose of science is to tentatively support or reject ideas with existing evidence. Every hypothesis and theory in science is on the edge of error and is therefore testable....such as the various ideas of evolution.