Before we judge of them too harshly we must remember what ruthless and utter destruction our own species has wrought, not only upon animals, such as the vanished bison and the dodo, but upon its inferior races. The Tasmanians, in spite of their human likeness, were entirely swept out of existence in a war of extermination waged by European immigrants, in the space of fifty years. Are we such apostles of mercy as to complain if the Martians warred in the same spirit?
agirlnamedluna asked about the Tasmanians. Read more about the fate of the Tasmanian Aborigines at Wikipedia, and about Trugamini. I highly recommend Mudrooroo's 1983 novel Doctor Wooreddy's Prescription for Enduring the Ending of the World for a fictionalized account of the lives of the last full-blooded Tasmanian Aborigines. Canadians should keep the fate of the Beothuk in mind.