Darwin's suggestion anticipates phylogenetic bracketing, a method based on that uses characteristics of organisms in a clade to make predictions about the common ancestor of the clade and all of its descendants.

The truman doctrine was an american foreign policy whose stated purpose was to counter soviet geopolitical expansion during the cold war. it was announced to congress by president harry s. truman on march 12, 1947, and further developed on july 12, 1948, when he pledged to contain threats to greece and turkey