Mutations are changes in traits that already exist;
Uh, no, that's not what mutation is. Mutation is a copying error when DNA is being used to create new proteins. The author again, is trying to confuse the reader to make them think that mutations and the natural changes we see through the reproductive process are the same. They are not. One is designed and results in diverse life (within their kind) and one scrambles the perfect code that God created (mutations).
For more on mutations:
https://www.thecreationaccount.com/evolution-of-life

