A lack of understanding about fetal skeletal development led researchers to form "overzealous conclusions" about the genome of a mummified skeleton that was found in the Atacama region of Chile, writes Kristina Killgrove from University of North Carolina-Chapel Hill at Forbes.
In March, a team led by the University of California, San Francisco's Atul Butte and Garry Nolan reported in Genome Research that they sequenced the genome of the Atacama skeleton. They said the sample harbored a number of novel mutations in genes associated with skeletal malformations that could account for the mummy's appearance: the mummy, which was estimated to be between six and eight years old at death, was small with an elongated head and had fewer ribs than usual.
But in an analysis appearing in International Journal of Paleopathology, Killgrove and her colleagues say that the UCSF-led team made a number of errors. They note that original assessment of the mummy's skeleton was never published in a peer-reviewed journal and that, rather than belonging to a six- to eight-year-old child, they say it may have belonged to a 15-week-old fetus. Rather than the skeleton being abnormal, the critique's authors say it instead represents an early stage of development. Based on that, they argue that the UCSF-led team's conclusions tying certain genomic regions to skeletal abnormalities are erroneous.
Chilean and other researchers also previously argued that the study itself was unethical and that the skeleton may have been illegally exhumed and taken from Chile. The UCSF-led team noted it was not involved in samples collection and that when it started its analysis, there were uncertainties about the age of the sample and even its species. In a statement at the time, Genome Research said that as the mummy's origins were uncertain, it didn't fall under human subjects research as defined by the Federal Office of Human Research Protections.
Killgrove and her colleagues also questioned the ethics of the study. They said that, as the sample was estimated to be about 500 years old or even much younger, the study should have followed either archaeological or forensic ethics. "[O]nce her humanity was confirmed, analysis should have stopped and her body should have been repatriated to Chile," she and her colleagues write in their analysis.