The evidence of evolution is clearly seen in numerous fossils and in DNA. Even if not observed in real time, this evidence is regarded as conclusive.
Evolution, the change in allele frequency over time in a population of organisms, is an observed and observable fact. That's why.
All educated people accept evolution and the theory that explains it. " Evolutionist " is a term not used among biologists. Even if there were no " evolutionists " evolution would still be an observed and observable fact and the theory of evolution by natural selection would still be the best explanation for much of the fact of evolution.
A gradual change in life-forms over time is organic evolution.
Rather both. Evolution, the change in allele frequency over time in a population of organisms, is an observed and observable fact. The theory of evolution by natural selection explains this fact with overwhelming evidences from many different disciplines.
Evolution is an observed and observable fact. The theory of evolution by natural selection explains many things about evolution. The theory generates testable hypothesis, as any good theory does. Remember, theory is the highest concept in science.
Evolution is descent with modification. Or, change over time. And formally as the change in allele frequencies over time in a population of organisms. This is an observed and a observable fact. The theory is; the theory of evolution by natural selection, which explains the fact of evolution. Natural selection is the main mechanism ( there are others ) that drives the adaptive change in organism that can lead to speciation, or just simple evolution.
To explain the species problem, " that mystery of mysteries " which was the natural history problem of the day. From his observations and experiments Darwin proposed his theory of evolution by natural selection, which provided a mechanism for the observed fact of evolution.
"Theory" means something much different in the world of science than it does in everyday use. Evolution is an observed fact. The theory around it is just our current understanding of the specific mechanics of it.
Evolution is routinely observed both in nature and in the lab. Even several speciation "events" are on record.
The theory predicts that evolution will happen and in certain ways. The observed evolution makes this prediction correct. It also defines evolution as happening, and as such is perfect evidence in support of it.
The best way to respond to this is to explain that there is the fact of evolution and the theory of evolution. Evolution is defined as genetic change within a population. This is an easily observable fact both in nature and the laboratory. The theory of evolution is an explanation for the diversity of life on earth based on the observable facts that evolution does indeed occur. It is exactly the same situation with gravity. Gravity is a fact, an easily observed physical phenomenon. But there is also a Theory of Gravitation, an explanation for the phenomenon itself and how it works. That there is a theory for both evolution and gravity does not mean the facts of evolution and gravity are any less true.
There is no such reason. Evolution, the change in allele frequency over time in a population of organisms, is a fact and as much a fact as the sun rising in the East every day. The theory of evolution explains much about the fact of evolution and is supported by more evidence that the fact that the sun seems to rise in the East is explained by the theory of heliocenterism.