Liddle makes an oversight in his piece. He basically claims that because atheists believe in Darwinism and Darwinism's core principles leave no room for what we call morality, Darwinism therefore leaves no room for morality it all. Although "natural selection" and "survival of the fittests" are core principles of Darwinism there is a Darwinian explanation for morality.
Mortality is a meme
(coincidentally, a term which Dawkins coined), a viral entity which infects the vast majority of us. Those of us who are not infected by it suffer a sort of artificial selection: the people who steal and kill are imprisoned; the people who are antisocial are socially shunned; the people throughout history who are immoral (like Hitler or Stalin) are vilified and people who were moral visionaries (like Jesus or Confucius) are praised centuries after their deaths. It follows then that morality can be considered a "fit" property of humans. Further, memes are themselves evolved* and thus subjected to all the core principles of Darwinism.
*And our morality has evolved! Here in the States people are generally less sexist and racist than they would have been as little as fifty years ago. (Ironically, atheists are one of the few people who could be still be considered true outcasts in even liberal American society. As the comedian Bill Maher said, we have a more diverse Congress, one that looks like America, but there are no diversity of ideas.)