Questioning the Questionable: The idea of missing links

Primate drawings from Brehms Tierleben

Image via Wikipedia

I recently came across an old and outmoded idea, dating back to early 20th century ideas on evolution, namely that of the so-called ‘missing link,’ which is still perpetuated by many creationists arguing against evolution.

This is an idea that involves questioning that ‘man evolved from apes‘ (or monkeys, take your pick…), a straw-person, since no reputable biologist argues this, and is based upon the ‘ladder of evolution’ or ‘great chain of being‘ fallacy, the idea that evolution is linear, like the rungs on a ladder from lower or more primitive species to higher, more advanced ones and the idea that evolution has a certain ‘direction’ or goal it must move toward.

This is unlike Darwin’s own actual concept of a sort of tree of life, or shrub, in which species can be compared to ever more branching limbs and twigs, that spread out and diversify over time, but without any goal or directional intent existing in the process.

This more accurate view is used today in biology and in which living things are simply different from one another, and in which humans are not descended from apes, but jointly descended along with other present-day primates from an earlier common primate ancestor that over time diversified into the modern species we see today.

We did not, of course, come from modern apes, or monkeys, or from any species currently extant, but from an earlier ancestral species that was simply different, not ‘lower’ than we on the rungs on a ladder or links in a chain, but which diverged in response to selective pressures and branched out into the current species over millions of years.

All current hominids descend from a common, earlier and presumably extinct form of apelike ancestor, itself branching off from its contemporaries from still earlier primates, those descending from a still earlier mammalian species, themselves deriving from proto-mammals and ultimately stretching all the way back some several billion years to the earliest self-replicating bacteria-like cells, and before them, earlier proto-cells following the origin of the molecular precursors of life on the early Earth.

There is no such thing as a ‘missing link’ and never was, for it assumes an argument that modern biology does not make, and I find it curious that anyone would take it seriously as a genuine weakness in evolutionary biology.

Then again, when one makes use of erroneous facts in support of an argument, the only way to do so consistently and effectively is with equally erroneous logic, something that in any sort of science denial is invariably committed by those so denying.

Go figure.

Advertisements

4 thoughts on “Questioning the Questionable: The idea of missing links

  1. This is why people should read Origin of Species. It’s not just creationists who get this wrong; the general population tends to think of evolution as an internal force pushing us upward toward progress (tell that to all the extinct species).

    As you note, Darwin does not have this linear ascent; it’s more like a bush (he even has a diagram). This notion of ever-upward progress seems to be an appropriation of evolution, harnessed to the ideas of perfectability, salvation, fate — and all that metaphysics that does not beling.

    Like

    • Yes. I’ve noticed that a book I read once by Julian Huxley was suffused with the notion of a directional drive, and that same idea could have influenced the circumstances of the Piltdown hoax and the time it took until it was finally exposed.

      Like

  2. Michael Ruse, philosopher of science and all-around sensible person, has an excellent and accessible book about how epistemic and cultural values shape science — and shape what scientific findings mean (_Mystery of Mysteries: Is Evolution a Social Construction?_, 2001). He has a lot to say about Huxley.
    If, like me, you haven’t read either Popper or Kuhn, Ruse starts the book by guiding the reader (gently) through their theories of science (well enough that I was later nerved to read Popper’s statements about evolution).

    Like

Commenting below. No spam or trolling, or my cats will be angry.

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s