The last thing we want to do is water down the teaching of biology because some people don’t recognize that evolution happened. Evolution is the basis of modern biology and, in fact, if a lot of people don’t believe it, it only means we have to do a better job teaching it. So once again, I repeat, the purpose of education is not to validate ignorance, but to overcome it. And to overcome a situation where a United States Senator can speak such manifest nonsense with impunity is vitally important to the healthy future of our society.
Thank you, Lawrence Krauss. I think rejection of evolutionary realities--in effect, the rejection of most of biology, genetics, geology, and more--is a singular disqualification for public office. If someone can be so conspiracy-minded and willfully ignorant as to not "believe" in evolution as the only scientific explanation for the origin of species, what other realities will he or she fail to see or understand, a consequence of their epistemological and psychological contortions?
Every time a fossil is found it proves evolution all over again, every time a geneticist observes genetic recombination it proves evolution all over again. Relative to the latter point: That's why genetics in and of itself is the ultimate proof for evolution. Darwin didn't know how heredity worked, not that it had to be part of the larger picture of evolution: no heredity, no evolution through natural selection. That mechanism of heredity was, eventually, discovered: heredity works through units we call genes. It was the great discovery of biology after evolution itself.
This is why the emergence of genetics brought about what is called the new synthesis or modern evolutionary synthesis. Genetics + Darwinian Evolution = a wondrous foundation for our understanding of life, an understanding that is an exciting adventure for 100,000's of scientists who investigate, challenge, confirm, refute, validate, invalidate, observe, expand, refine, enhance, reform and predict about biological evolution on a daily basis, as well as about other realms of science that the theory of evolution incorporates--geology, population genetics, chemistry, ecology, etc.
The theory of evolution isn't "just" a theory. In formal scientific nomenclature, theory doesn't mean a guess, but means an overarching concept that synthesizes myriad laws and observations. It's the same notion of theory at work in the germ theory of disease, the theory of general relativity, or the theory of plate tectonics. Because plate techtonics is a theory, do you doubt that the earth has continental plates and instead believe that earthquakes are caused by gnomes burrowing underground? No, you don't. Relative to plate tectonics, no one asserts that it's "just a theory." No, that is reserved for evolution, and it is one of the oldest and most misguided of evolution-denial's canards.