March of Progress

Original intent

Contrary 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 of which are in the direct line of human ancestors, would not be a correct interpretation. For example, the fourth of Zallinger's figures (Oreopithecus) is said to be "a likely side branch on man's family tree". 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). This implies that none of the first four primates are to be considered actual human ancestors. Likewise, the seventh figure (Paranthropus) is said to be "an evolutionary dead end". In addition, the colored stripes across the top of the figure that 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 that multiple lineages of the figured hominids occurred contemporaneously at several points in the history of the group.

Original sequence of species

The 15 primate figures in Zallinger's image are, from left to right, as follows (the datings follow the original graphic and may no longer reflect current scientific opinion):

Pliopithecus, 22–12 million year old "ancestor of the gibbon line"

Proconsul, 21–9 million year old primate which may or may not have qualified as an ape

Dryopithecus, 15–8 million year old fossil ape, the first such found (1856) and probable ancestor of modern apes

Oreopithecus, 15–8 million years old

Ramapithecus, 13–8 million year old ape and possible ancestor of modern orangutans (now considered a female Sivapithecus)

Australopithecus, 2–3 million years old; then considered the earliest “certain hominid”

Paranthropus, 1.8–0.8 million years old

Advanced Australopithecus, 1.8–0.7 million year old

Homo erectus, 700,000–400,000 years old, then the earliest known member of the Homo genus

Early Homo sapiens, 300,000–200,000 years old; from Swanscombe, Steinheim and Montmaurin, then considered probably the earliest H. sapiens

Solo Man, 100,000–50,000 years old; described as an extinct Asian "race" of H. sapiens (now considered a sub-species of H. erectus)

Rhodesian Man, 50,000–30,000 years old; described as an extinct African "race" of H. sapiens (now considered either H. rhodesiensis or H. heidelbergensis and dated much earlier)

Neanderthal Man, 100,000–40,000 years old

Cro-Magnon Man, 40,000–5,000 years old

Modern Man, 40,000 years to present

Criticism

Evolutionary biologist Stephen Jay Gould (1941–2002) condemned the iconology of the image over several pages of his 1989 book Wonderful Life. In a chapter entitled "The Iconography of an Expectation", Gould asserted that

The march of progress is the canonical representation of evolution – the one picture immediately grasped and viscerally understood by all.... The straitjacket of linear advance goes beyond iconography to the definition of evolution: the word itself becomes a synonym for progress.... [But] life is a copiously branching bush, continually pruned by the grim reaper of extinction, not a ladder of predictable progress.

Gould reproduces several advertisements and political cartoons incorporating the March of Progress to convey one message or another. He even presents a "personally embarrassing" example: one of the four foreign editions of his books (over the design of which he had no control) which used the "march of human progress" as a jacket illustration. Gould never actually mentions Zallinger or the Time-Life Early Man volume in his critique, giving only vague clues as to the origin of the concept.

Intelligent design advocate Jonathan Wells wrote in Icons of Evolution: Science or Myth? (2002) that "Although it is widely used to show that we are just animals, and that our very existence is a mere accident, the ultimate icon goes far beyond the evidence." The book takes its title from the illustration and its imitations.

Parodies and adaptations

A 1966 advertisement for Greg Noll Surfboards' "Da Cat" model (based on the popularity of Malibu surfer Miki Dora) appropriated the Zallinger image to parody the evolution of surfing personas.

The logo for the Leakey Foundation features a small silhouette of the March of Progress image.

The National Museums of Kenya in Nairobi have long utilized a logo based on the Zallinger image.

The cover of the 1972 Doors album Full Circle references the March of Progress.

The cover of the 1985 Supertramp album Brother Where You Bound resembles the March of Progress.

On the cover of the soundtrack CD for the 1992 movie Encino Man, an ape evolves into a skateboarder.

The 3 March 1994 issue of Time magazine includes a graphic, "Humanity's Long March", referencing Zallinger's image with a more complicated graphic underneath.

A 1998 issue of Rolling Stone features an image of actor Ben Stiller evolving from a hairy ape into a naked actor.

A graphic in the December 2005 issue of The Economist depicts hominids progressing up a flight of stairs to transform into a woman in a black dress holding a glass of champagne.

Predecessor

An illustration, with the caption "Evolution," showing two sequences of four images, each illustrating a gradual transformation of an animal into a human, appeared in the 1889 edition of Mark Twain's A Connecticut Yankee In King Arthur's Court: