The issue of natural selection and survival of the fittest refers to selection processes that act on the reproductive success of the organism, and not on how strong it is, how pretty it is, etc. That is, reproductive success is all that counts. Second, evloution does not mean that there is no God (as Ann points out). Third, all the data that bioscience has amassed since The Origin of Species was published has provided mechanisms and corroboration for his basic insights. For example, comparative anatomy, embryology, genetics, proteomics, etc. The evolutionary model fits best with the facts as we know them: when a better theory or model comes along (that is, it explains the facts better than evolution) science will eventually embrace the new. Untill then...
She does not state that. She states the science developed after The Origin of the Species refutes his theory, it does not back it up. Are you reading the same book?