"Fossils May be Humans’ Missing Link" reported the Washington Post on April 22, 1999, explaining that newly discovered Ethiopian fossils "may well be the long-sought immediate predecessor of human beings." But almost fifty years earlier, paleontologist Robert Broom published Finding the Missing Link, a book about his discovery of fossil "ape men" in a crumbling South African cave. Indeed, the phrase "the missing link" was commonly used even before Broom, and reports of the discovery of "missing links" have been continuous since the 1850s (1).
You have to ask, "What’s going on?" How is it that the missing link has been discovered repeatedly, for at least fifty years, and in places as widely separated as South and East Africa? Are there lots of missing links, or just one? What exactly is a missing link, and do anthropologists really spend their lives searching for them? We only really hear about missing links between people and apes, but do other life-forms have missing links? "The Missing Link" is a common phrase that causes confusion. It also gives rise to two major misconceptions.
First, the phrase leads directly to a profound misunderstanding of the world of living things because it promotes an essentially medieval view of nature, one in which species are fixed "types," or "links," that don’t change through time. But as we’ll see throughout this book, this view is at spectacular odds with the essence of evolution, which is change. Species can’t be both changeable and unchangeable over time, so we have a major issue to sort out here.
Second, the phrase leads to misconceptions about the study of ancient life and the people who study it. While evolutionary scientists do sometimes seek missing links, they do a lot more than that, and there’s far more involved in the studies of ancient life than the quest for the missing link.
A complicating factor here is that there are missing links, but their real significance is often lost in the mass media. Luckily, with a bit of thought, it becomes clear what the term really means.
We have a lot of issues to grapple with here: the myth of single Missing Links, the concepts of changeability and fixity, and misconceptions about what people who study ancient life really do. To clarify what’s meant by the common use of "The Missing Link," let’s start with the origins of the phrase, and then see how that concept matches up with what we know about biology today.
Notes to Myth Four: The Missing Link
1. Even today, the excellent television program NOVA aired an entire series on the story of life of the missing link. This was originally broadcast on PBS in 2002, and aside from the problematic (as we saw in this chapter) title, the series is excellent.