" I'm a bit surprised you did't pick up on that, Stu, to be honest."

But she is talking about genes, albeit the effects of mutation rather than mutation itself.

I'm guessing this is difficult to sum up in a couple of paragraphs for a general readership, but I still see nothing wrong with either. They're discussing the flow of information and the agents that affect that flow. Mutations resulting in different alleles (variations of a gene, eye colour for instance) are not adaptive, but might confer an advantage on an animal carrying that mutation; equally they might not make any difference or be a disadvantage. Of course they touch upon sexual selection as being another driver of evolution, and there are others of course but for a laypeople this might all get a bit confusing.

All they're saying is "survival of the fittest" is not how evolution works; it should be "survival of the best adapted".