The image has been described as having a "visual logic" of linear progression. It has been criticized as "unintentionally and wrongly" implying that " evolution is progressive". The image has frequently been copied, modified, and parodied. In addition, the colored stripes, across the top of the figure, which indicate the age and duration of the various lineages clearly imply that there is no evidence of direct continuity between extinct and extant lineages and also, multiple lineages of the figured hominids occurred contemporaneously at several points in the history of the group. Likewise, the seventh figure ( Paranthropus) is said to be "an evolutionary dead end". That implies that the first four primates are not to be considered actual human ancestors. Only the next figure ( Ramapithecus) is described as "now thought by some experts to be the oldest of man's ancestors in a direct line" (something no longer considered likely). For example, the fourth of Zallinger's figures ( Oreopithecus) is said to be "a likely side branch on man's family tree". Modern Man, 40,000 years to the presentĬontrary to appearances and some complaints, the original 1965 text of "The Road to Homo Sapiens" reveals an understanding of the fact that a linear presentation of a sequence of primate species, all in the direct line of human ancestors, would not be a correct interpretation.Rhodesian Man, 50,000–30,000 years old described as an extinct African "race" of H.sapiens (now considered a sub-species of H. Solo Man, 100,000–50,000 years old described as an extinct Asian "race" of H.Early Homo sapiens, 300,000–200,000 years old from Swanscombe, Steinheim and Montmaurin, then considered probably the earliest H.Homo erectus, 700,000–400,000 years old, then the earliest known member of the genus Homo.Advanced Australopithecus, 1.8–0.7 million year old.Paranthropus, 1.8–0.8 million years old.Australopithecus, 2–3 million years old then considered the earliest "certain hominid".
The 15 primate figures in Zallinger's image, from left to right, are listed below. The first two sentences of the caption read "What were the stages of man's long march from apelike ancestors to sapiens? Beginning at right and progressing across four more pages are milestones of primate and human evolution as scientists know them today, pieced together from the fragmentary fossil evidence." Sequence of species The 15 human evolutionary forebears are lined up as if they were marching in a parade from left to right. It shows a sequence of figures, drawn by natural history painter and muralist Rudolph Zallinger (1919–1995). The illustration is a foldout entitled "The Road to Homo Sapiens". The illustration is part of a section of text and images commissioned by Time-Life Books for the Early Man volume (1965) of the Life Nature Library, by F.