Darwin’s primate tree

December 3, 2015 • 8:30 am

by Matthew Cobb

This sketch of human origins was made by Darwin in 1868, and reflects the knowledge of the time. Humans are on the left, with our closest relatives, gorillas and chimps, grouped together. Darwin seems to mistakenly suggest that the gibbons (Hylobatus) are more closely related to the other apes – gorillas, chimps and orang-utans – than we are.  Strikingly, there is no place on this sketch for any fossil forms, even though the first Neanderthal skull had been discovered in 1829, and the species name Homo neanderthalensis had been proposed in 1864.

[JAC: you’ll note that he also places chimps as more closely related to gorillas and orangs than to humans, which is another error, as chimps and bonobos are our closest relatives (ca. 6-6 myr), and both of us are a bit less closely related to gorillas (about 9 myr), and even less closely related to orangs (ca. 16 myr). But we had no genetic data back then, and this is a fine and prescient effort by Darwin.]

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This image, which is copyright by the Syndics of Cambridge University Library, can be found online here. A facsimile is currently on display at the Wellcome Trust Cultural Zone on The Genome Campus in Hinxton, Cambridge, with the following caption:

This diagram is the most tree-like of Darwin’s lineage drawings. It represents the evolutionary development of primates and highlights some key evolutionary distinctions that we still trace today. For example, on the left he notes the separation of Old World Monkeys and at the top he extends man from the same lineage as the other higher apes, such as gorillas and chimpanzees.

The diagram does not reference other species of hominids, though Darwin would discuss this subject a few years later in his book The Descent of Man, and Selection in Relation to Sex.

h/t Ewan Birney, with thanks to Rebecca Gilmore and Julian Rayner for helping track the image.

25 thoughts on “Darwin’s primate tree”

      1. Nope. From the website’s “shopping cart”, they’ll ship essentially anywhere.

  2. John Hawks discusses this tree here, and points out that in The Descent of Man in 1871 Darwin argues for the modern view that the African apes (gorilla and chimps) and humans form a clade. He notes that this 1868 view is closer to Wallace’s position that the human lineage separated from the lineage of apes before the common ancestor of apes.

    It was trees like Wallace’s that encouraged biologists in the mid-20th-century to go around saying that humans and apes had a common ancestor but that this ancestor was not an ape, so we are not descended from apes. Which is very comforting, but totally wrong.

    2. I don’t understand why it would be comforting, if our ancestor weren’t an ape, it would have been a monkey instead. How is that an improvement?

      1. “We need another and a wiser and perhaps a more mystical concept of animals. Remote from universal nature, and living by complicated artifice, man in civilization surveys the creature through the glass of his knowledge and sees thereby a feather magnified and the whole image in distortion. We patronize them for their incompleteness, for their tragic fate of having taken form so far below ourselves. And therein we err, and greatly err. For the animal shall not be measured by man. In a world older and more complete than ours they move finished and complete, gifted with extensions of the senses we have lost or never attained, living by voices we shall never hear. They are not brethren, they are not underlings; they are other nations, caught with ourselves in the net of life and time, fellow prisoners of the splendour and travail of the earth.”

        Beston, Henry. “The Outermost House,” 1926.

        Does it matter from which particular branch Homo sapiens emerged? Sometimes I feel like an ape, sometimes I fear I fall short (npi). I hope not to make a monkey of myself too often . . . but then, why not?

  4. I had thought that back then some had considered gorillas to be more closely related to humans than are chimpanzees, but he seems to be lumping gorillas w/ chimps here.

  5. “Darwin seems to mistakenly suggest that the gibbons (Hylobatus) are more closely related to the other apes – gorillas, chimps and orang-utans – than we are.”

    More than that, Darwin’s tree actually implies that we are equally closely related to ALL the apes, since we share common ancestry with all of them at the exact same node of the tree – unless, of course, Darwin assumed that the left-to-right order of taxa somehow conveyed relatedness instead of, or in addition to, the actual branching order.

    1. Probably because fossils of ancestral species are found below those of descendant species.

    2. Actually, many trees are presented horizontally, and some have to portray so many branches that the tree is bent back on itself, so that it forms a circle (that of course doesn’t actually close on itself).
      Because of these arbitrary conventions, it is often hard to get students to read trees correctly. If is a vertical tree they have to pay no attention to the arbitrary left-to-right arrangement of taxa (only the branching order from bottom to top), and if it is a horizontal tree they need to do ignore the top-to-bottom arrangement (only the branching order from left to right).

  8. Interesting facts about the early Neanderthal fossils not being given a branch. Did Darwin ever mention Neanderthals?

    1. Oops…I saw that he did mention other hominids in The Descent of Man. Didn’t read carefully enough.

  9. It’s wonderful to imagine Darwin sketching that out (and conceiving of it in the first place, of course).

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