Who cares!
He's wrong!
And how are you so certain that he's wrong? Have you studied biology? Taken the time to get a Ph.D. (as I have), thereby demonstrating that you have a good understanding of the basic science as it stands now? Have you ever undertaken a research project aimed at understanding the differences between two similar species, and then, furthermore, tried to carry out the project while handicapping yourself by refusing to look at any research that touches on the evolutionary aspects of the differences?
Until you have that kind of knowledge and experience about what we do in the biological sciences, you really have no basis on which to call someone who correctly states "Evolution is a cornerstone of modern biology" a liar.
Of course that is ALL they teach so I'm not surprised you don't think for yourself! Indoctrination doesn't make it so and I know of folks MORE qualified than YOU who see things VERY differently.
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Saying that someone is wrong is not the same as calling them a liar. A person can come to an incorrect conclusion innocently.