By Stephen Beech via SWNS
Human remains have been found embedded in the teeth of two lions on display in a museum.
The Tsavo “man-eaters” became infamous after killing at least 28 people in 1898 when they terrorized an encampment of bridge builders on the Tsavo River in Kenya.
The massive and maneless lions crept into the camp at night, raided tents and dragged their victims off into the bush.
They were eventually shot dead in December 1898 by Lieutenant-Colonel John Henry Patterson, the civil engineer on the project.
Patterson kept the lions’ skins as floor rugs for 25 years before selling their remains to the Field Museum of Natural History in Chicago, for $5,000 in 1924.
The skins arrived at the museum in poor condition but were reconstructed and put on display, along with their skulls.
Now Field Museum researchers have teamed up with scientists at the University of Illinois Urbana-Champaign on an in-depth analysis of hairs carefully extracted from the lions’ broken teeth.
The study used state-of-the-art microscopy and genomics to identify some of the species the lions consumed.
The original discovery of the hairs occurred in the early 1990s, when Thomas Gnoske, a collections manager at the Field Museum, found the lions’ skulls in storage and examined them for signs of what they had eaten.
He was the first to determine that they were fully grown older adult males – despite being maneless.
Gnoske was also the first to notice that thousands of broken and compacted hairs had accumulated in exposed cavities in the lions’ damaged teeth during their lifetimes.
By isolating and sequencing DNA in the hairs, the researchers discovered that the lions preyed on animals including giraffes and wildebeests – as well as humans.
The lions in the study, published in the journal Current Biology, had dental injuries, including partially broken canine teeth exposing cavities where hair from their prey built up over time.
From those tooth cavities, the researchers extracted DNA from individual hair shafts and tiny clumps of hair fragments.
While the DNA in those samples was degraded in ways that are typical for historic or ancient DNA, they were able to piece enough of it back together in some of the samples to identify the species the hair originated from.
They ultimately identified six prey species: humans, giraffe, oryx, waterbuck, wildebeest, and zebra.
Dr. Alida de Flamingh, of the University of Illinois Urbana-Champaign, said: “A key part of this study was to create a method to extract and analyze DNA from single hairs of prey species found in the teeth of historical museum specimens.
“Our analysis showed that the Tsavo lions preyed on giraffe, human, oryx, waterbuck, wildebeest, and zebra, and we also identified hairs that originated from lions.
“This method can be used in many ways, and we hope other researchers will apply it to study prey DNA from other animal skulls and teeth.”
The research team was most surprised to find hair from wildebeest, noting that it raises questions about their distribution in the past.
Dr. de Flamingh said: “It suggests that the Tsavo lions may have either traveled farther than previously believed, or that wildebeest were present in the Tsavo region during that time.
“The closest grazing area for wildebeest was over 50 miles from where the lions were killed in 1898 at the Tsavo-Athi confluence.”
Once the samples were authenticated, Dr. de Flamingh focused on mitochondrial DNA.
In humans and other animals, the mitochondrial genome is inherited from the mother and can be used to trace lineages through time.
Dr. de Flamingh said: “Because the mitochondrial genome is much smaller than the nuclear genome, it’s easier to reconstruct in potential prey species.
“We were even able to get DNA from fragments that were shorter than the nail on your pinky finger.”
The lions were found to share the same maternally inherited mitochondrial genome, supporting early reports theorizing that they were siblings. Their mtDNA was also consistent with an origin in Kenya or Tanzania.
The researchers also found that the lions had eaten at least two giraffes, along with a zebra that likely originated in the Tsavo region.
Historical reports noted that the lions left the Tsavo region for about six months before resuming their rampage at the bridge-builders camp.
However, the absence of buffalo DNA and the presence of only a single buffalo hair – identified using microscopy – surprised the research team.
Dr de Flamingh said. “We know from what lions in Tsavo eat today that buffalo is the preferred prey.”
Professor Julian Kerbis Peterhans, of Roosevelt University in Chicago, said: “Colonel Patterson kept a handwritten field journal during his time at Tsavo.
“But he never recorded seeing buffalo or indigenous cattle in his journal.”
Kerbis Peterhans explained that at the time the cattle and buffalo populations in that part of Africa were devastated by rinderpest, a highly contagious viral disease brought to Africa from India by the early 1880s.
He said: “It all but wiped out cattle and their wild relatives, including cape buffalo.”
He said the mitogenome of the human hair has a broad geographic distribution and the scientists declined to describe or analyze it further for the current study.
Kerbis Peterhans said: “There may be descendants still in the region today and to practice responsible and ethical science, we are using community-based methods to extend the human aspects of the larger project.”
Anthropology Professor Ripan Malhi, also of the University of Illinois Urbana-Champaign, said: “As biotechnologies advance, there are unexpected sources of knowledge, in this case genomics, that can be used to inform about the past.”
He added: “This methodology can potentially be used on hairs from broken teeth of more ancient carnivores from hundreds to thousands of years ago.
“The method opens up a new avenue of inquiry into the past.”
