Although that is a one-sided account of Darwin’s moral theory, even according to this text his views were a far cry from regarding humanity as having “animal lusts with no morality”. If the account you linked is accurate, then it is quite different from Nietzsche’s theory of how moral conventions arose, so how can one juxtapose the two, except out of ignorance?
Although we today regard advocacy of eugenics as shocking, it was prevailing wisdom among the educated persons of his day. It is historicism to condemn him for rationalizing a conventional opinion.
On a similiar note, there are numerous Christian apologia for slavery from the 18th and 19th centuries. The pagan festival of Saturnalia persisted into the 16th century under sanction of the Church, during which Jews would be stripped naked and chased through the streets of Rome. Is it fair to say that what is perceived as Christian morality has ...changed?
I think we have changed. I believe that the West has become more morally aware over time (and I don’t mean “better”)- that we have become more aware of the “other”, broadening our scope of empathy beyond tribe, race, and country. In other words, we are inching closer to God in an individual, non-utopian, non-hubristic sense. Darwin was indeed secular, but I think his observations were his attempt to describe and understand the same phenomenon. I do not regard his views as offensive or ridiculous, or even particularly wrong. Incomplete, perhaps, but not necessarily wrong.
Teilhard de Chardin had similar views (cf. the noosphere), and I think Teilhard’s Jesuitical mysticism endowed the idea with a certain beauty. Flannery O’Connor found poetry in Teilhardism, and understood the relevance to the morality of everyday life, and wrote “Everything that Rises Must Converge” as a tribute to his philosophy.