Another Human Hybrid? The Controversy Continues One Year Later
Last year, we reported on the results of genetic research which revealed that the genome of one of our ancient ancestors, the Denisovans, contains a segment of DNA that seems to have come from another species that is currently unknown to science. Several recent studies have also revealed that modern humans are a product of hybridization, with remnants of Neanderthal and Denisovan genomes in our DNA. This research leads us to realize that our understanding of the origins of modern humans is much murkier than we ever thought possible. This also begs the question, if we are hybrids already, could there be extant human hybrids currently on earth besides us?
It was a year ago today that a bold and controversial study claiming to have sequenced three whole genomes from the species known as Sasquatch or Bigfoot was published, titled ‘Novel North American Hominins, Next Generation Sequencing of Three Whole Genomes’. This study was met with outrage by some scientists, while much of the scientific community ignored it altogether. Some scientists supported it, but most were afraid of what would happen to their careers if they openly supported a study claiming to have proven the existence of the much stigmatized and controversial Sasquatch. Yet upon examination of the paper, it can be seen that it was a huge multidisciplinary effort involving a dozen labs and blind studies, and carried out by nine highly qualified scientists, aimed at quelling controversy about the discovery.
Sasquatch is the name given to a cryptid ape- or hominid-like creature that some people believe inhabits forests, mainly in the Pacific Northwest region of North America. It is usually described as a large, hairy, bipedal humanoid. In many ancient cultures, there are historical accounts, legends, artwork and stories about giants, hairy people, wild people, and other beings fitting the basic description of the Sasquatch. In North America, the Sasquatch are considered to be a tribe by many Native American people. They are known by dozens of names, including Big Foot in America, Almas in Russia, Yeren in China, Yeti in Tibet, Yowie in Australia, and Elder Brother among Native Americans. Virtually every country and culture has a name for them.
At some point, the Sasquatch faded into mythology and reporting one became a reason to ridicule the witness. Nevertheless, individual reports continue to be submitted to local authorities and research organizations describing this elusive creature in detail. These reports document sightings, encounters and tangible pieces of evidence such as footprints, vocalizations captured on audiotape, photographs, video footage and hair samples. Some are clearly hoaxes designed to make fun and ridicule the subject, while others are simply left as unexplained.
Overview Map of North American Bigfoot Sightings as reported by selected Bigfoot research organization web sites. Image credit.
In the most extensive study ever carried out on the subject, a total of 111 samples were analysed, and standard procedures used in forensic science were implemented, including blank and positive control samples, submitter profiles and laboratory personnel profiles, all of which were utilized in conjunction with the testing of the samples. Laboratories and scientists were not told what they were testing when they were contracted to test the Sasquatch samples. This ensured the integrity of the replication of the findings from test to test to test.
Dr. Melba Ketchum of Nacogdoches, Texas, a veterinarian, forensic scientist, and the lead author of the study, claims that the crux of what has the scientific community is in an uproar about is that the samples had human mitochondrial DNA (maternal lineage), while the nuclear DNA (paternal lineage) was a structural mosaic consisting of both human DNA and novel non-human DNA, which did not match any known species in GenBank. The paternal lineage suggests a distantly related hominin that evolved separately from humans, apes and other primates but evolved to the point where it could interbred with humans. A year ago, this might have been difficult for many scientists to believe, but with the recent studies touting that unknown DNA has been found in ancient hominins which bred with humans, one has to wonder if their hypothesis is as far off as some believe.
The five year study costing over half a million dollars employed university laboratories, accredited private laboratories, state government and private forensic laboratories in its quest to test whether the Sasquatch truly existed or not. The different analyses in the study included genotyping using short tandem repeats (molecular biology method used to compare specific loci on DNA from two or more samples), standard nuclear and mitochondrial DNA sequencing, Next Generation whole genome sequencing as well as whole genome SNP arrays, electron microscopy, forensic hair analysis and histopathology (microscopic examination of tissue). The labs responsible for the testing are listed in the paper and all data and test results are publicly available. This was no small study and whether you agree with the findings or not, the best cutting edge technology was utilized to generate the results. Furthermore, ZooBank, the official International Commission on Zoological Nomenclature, has recognised the study by publishing the name that the scientists in the study requested for the new species, Homo sapiens cognatus. One translation of cognatus means blood relative.
The critics of the study say that the samples must have been animal DNA contaminated with human DNA. However, with the authors being forensic scientists, dealing with contaminated samples is a common occurrence that can be tested for. Not only were the DNA hair samples washed to remove contamination, but all samples were screened using species identification sequencing techniques that will work in all mammals. If the samples were contaminated, the electropherograms (the graphic representation of the sequences generated by the sequencer) would have shown the sequences from the different species superimposed on one another. Another critique of the study claims that the DNA must have been degraded. But according to yield gels, the DNA in almost all of the samples exhibits no appreciable degradation, which would appear as smearing instead of a clean band on the gel.
Nothing has been per the status quo with this DNA study. First, there were numerous attempts to have the paper published via main stream science journals. Even with all the science incorporated in the study, only one, the well-known journal Nature, accepted the paper and sent it for peer review. Later, the Journal of Advanced Zoological Exploration in Zoology accepted the paper and it passed peer review, but they backed out of publication on the day the paper was to go live. In yet another ridiculous controversy, GenBank refused to allow the team to upload their sequences, sending emails requiring signed consent forms from the individuals the samples came from (i.e. Sasquatch!), prior to acceptance of the sequences, among other excuses.
One aspect that the study authors certainly cannot be criticized for is a lack of transparency. The entire study, as well as a huge amount of raw data and supplemental material is freely available on their website and Dr Ketchum has invited scientists worldwide to examine it and offer responsible feedback. While some researchers have embraced her findings, many more have dismissed them, based on an insufficient grasp of the data or a neglect of the data altogether. Others have superficially tried to ‘debunk’ the results by making personality attacks on Dr Ketchum, but who failed once again to discredit any of the actual scientific results.
Finally, there have been death threats leveled at scientists in the study, not to mention a pipe bomb that was detonated at a venue where Dr. Ketchum was scheduled to speak, further highlighting the fact that the implications of the study are so profoundly challenging to conventional perspectives that people are willing to take such extreme measures to protect their deep-rooted and preconceived notions. But one has to wonder, what is so polarizing about the presumptive proof of the existence of an extant human hybrid that precipitates such fervor? Hopefully, time will unravel this mystery.
By John Black
Watch interviews with Dr Melba Ketchum
Ketchum, M. S., Wojtkiewicz, P. W., Watts, A. B., Spence, D. W., Holzenburg, A. K., Toler, D. G., Prychitko, T. M., Zhang, F., Shoulders, R., Smith, R. (2013) "Novel North American Hominins, Next Generation Sequencing of Three Whole Genomes and Associated Studies"