For the most part, Bigfoot research involves collecting sighting reports. An awful lot of Bigfoot researchers shy away from expressing any opinions or theories about the creatures they study. At best, they might say they believe Bigfoot is a real animal, not a myth or delusion. Yet everyone has an opinion, whether they want to risk verbalizing it or not. Forming opinions—good or bad, right or wrong—is a part of human nature.
So what is Bigfoot? Ape, hominid, human, alien…Before we can answer that question unequivocally, we must first understand our own origins. We know where human beings came from, right? Well, maybe not.
Information about human origins comes from two sources—fossils and DNA. Fossils are rarer than most people think. A fossil is any remnant of a long-dead living thing, from bones to feces to impressions of body parts, that scientists unearth from the ground. The youngest fossils date back 10,000 years. The process of fossilization alters the chemistry of the carcass by adding, taking out, or substituting minerals. Other kinds of remains, such as mummies, are not technically fossils.
Now consider that scientists estimate upwards of 98% of all the species that have arisen in earth’s history have gone extinct. The fossil record preserves an estimated 10% of all species that have ever lived. Of the species we know existed, those named in our taxonomy of the natural world, over 80% coexist with us today. Thus, the fossil record contains a mere fraction of the life-forms that once populated this planet.
When it comes to putative ancestors of modern humans, the fossil record is even scarcer and the fossils themselves fragmentary and incomplete. For most of the species designated as human ancestors, the evidence for their existence consists of incomplete skulls and perhaps a few isolated bone fragments from the rest of the skeleton (see the drawing at left, which shows the evidence for the species Orrorin tugenensis). The fossil record provides nothing close to conclusive proof of how modern human beings arose.
Now consider the DNA evidence. Scientists have used the DNA of modern humans to construct a molecular clock that supposedly lets them count backward to any moment in the genetic history of our species. The molecular clock is supposed to tell us when specific mutations first appeared. This timeline is then used to calculate the dates of watershed events in human evolution.
When did the hominid branch split off from the trunk of the primate tree of life? When did Homo sapiens diverge from all other hominids? The molecular clock supposedly gives us these answers. The problem is, the DNA evidence often contradicts the fossil evidence. The molecular clock spits out dates that are much more recent than the timeline suggested by the fossils. This discrepancy brings up the major fault of the molecular clock. It relies on the assumption that mutations occur at a regular (i.e., clock-like), predictable rate.
This is hardly the case, however. Recently, two geneticists in England published a paper suggesting that the molecular clock may be off by half. Their study compared the DNA of modern human parents and their children to determine the speed at which mutations occur. Their research pointed to a far slower mutation rate, meaning that the molecular clock may need some serious recalibrating. For instance, as currently calibrated the molecular clock pinpoints the moment modern humans first left Africa 60,000 years ago. The newly proposed mutation rate would push back the human diaspora to 120,000 years ago—a date that meshes with the fossil record.
Yet even the newly calibrated molecular clock, if it becomes widely accepted, relies on the same assumption as the original clock. It assumes that mutations occur at regular, predictable intervals. Is this true? No one knows.
The vagaries of the fossil record and the DNA evidence makes the tale of human origins just that—a tale, a lovely little story. Despite centuries of intense scientific discussion and debate, the mysteries of our own origins still elude us.
And the mysteries of Bigfoot’s identity and origins are even more enigmatic.
Sharpe, Katherine. “Turning Back the Human Clock.” Archaeology, 66(1), p. 21.
Shiel, Lisa A. The Evolution Conspiracy, Vol. 1: Exposing Life’s Inexplicable Origins & the Cult of Darwin. Lake Linden, MI: Slipdown Mountain Publications, 2009. <http://www.jacobsvillebooks.com/nonfiction/EvolutionConspiracy.php>