This short article in the journal Endeavour takes a creationist claim about Darwin to task:
John van Wyhe
Abstract For decades creationists have claimed that Charles Darwin sought the skulls of full-blooded Aboriginal Tasmanian people when only four were left alive. It is said that Darwin letters survive which reveal this startling and distasteful truth. Tracing these claims back to their origins, however, reveals a different, if not unfamiliar story.