Arthur Keith. Historical portrait of the British anatomist Arthur Keith (1866-1955). He profoundly affected work on the evolution of humans. He proposed an early appearance of Homo sapiens, removing Neanderthal and Java man from the human ancestry. When the discovery of Piltdown Man was announced in 1912, Keith was among those who believed that this skull was a genuine link between humans and the apes. He lived long enough to hear of its exposure as a fraud in 1953. Keith also believed in fixed, hereditary hormonal differences between races. In 1907 (with M. W. Flack) he identified the region of heart tissue that triggers the heartbeat.