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In 1898, two male lions gained notoriety when they terrorized and ate humans during the construction of a railway bridge over the Tsavo River in Kenya. Now, innovative genetic analysis of hairs trapped inside the cavities of broken teeth has revealed new insights into the prey the so-called Tsavo cannibal once hunted.
The harrowing true story of a lion that attacked a camping tent at night and dragged its victim into the bush has inspired films and books over the years to understand what drives lions to prey on humans. It has also influenced a huge amount of research.
Lions killed at least 28 people, including workers on the Kenya-Uganda Railway, from April 1898 until civil engineer Lt. Col. John Henry Patterson shot and killed the giant feline. Patterson then sold the lion’s remains in 1925 to the Field Museum of Natural History in Chicago, where it has remained ever since.
Thomas Gnoske, the museum’s collections manager, first discovered thousands of hairs trapped in lion teeth when he examined a lion’s skull in the 1990s.
Now, Gnoske and his colleagues at the Field Museum in Kenya and the University of Illinois at Urbana-Champaign have isolated individual hairs and clumps of hair stuck inside tooth cavities and extracted DNA from them to determine where they belong. successfully identified the animal. . The findings suggest that the lion duo traveled further than previously believed in search of food.
The study was published Friday in the journal Current Biology. The researchers also said the method could reveal connections not only between living predators and their prey, but also between specimens that are hundreds of thousands of years old.
“An important part of this research was creating a method to extract and analyze DNA from a single prey hair found on the tooth of a history museum specimen,” said study lead author and University of Illinois at Urbana University said postdoctoral researcher Alida de Flamin. – Champaign, in a statement. “Our analysis shows that historical Tsavor lions preyed on giraffes, humans, oryx, waterbucks, wildebeest, and zebras, and we also identified lion-derived fur. We hope that other researchers will apply this method to study prey DNA from the skulls and teeth of other animals.”
Gnoske and his colleague and study co-author Julian Kerbis Petehans, adjunct curator at the Field Museum and professor of natural sciences at Roosevelt University, have been studying lion skulls for decades.
Gnosuke discovered that both lions were adult males, but both lacked the manes characteristic of fully grown males. The lack of a mane in adult male lions is common and can be caused by the environment and climate the animal lives in, injuries that occur as the mane develops, and other factors, he said. Ta.
Gnoske and Kelvis Peterhans also first reported the state of lion tooth damage in 2001, which may have been part of the reason why lions shifted their focus to attacking and eating humans. Their research suggests that one of the lions may have suffered damage from kicks and blows from the buffalo or zebra, making it unable to hunt its normal prey effectively.
“While no single cause can guarantee that a lion will turn into a ‘man-eater,’ it is clear that a variety of causes increase the likelihood,” the researchers wrote in a January 2001 study. are. Or a predator that is already interested in humans after scavenging a corpse.
The lion had numerous dental injuries, including some broken canines, and over time a layer of prey hair had built up.
For the new study, Gnoske and Carbis-Petehans carefully removed sections of hair. The research team focused on four small hairs and three hair clumps that were all well over 100 years old.
Co-authors of the study, Ogeto Mwebi, a senior researcher at the National Museums of Kenya, and Nduhiu Gitahi, a researcher at the University of Nairobi, conducted microscopic analysis of the hairs. Dr. de Flamin then led a study of the hair genome with study co-author Ripan S. Malhi, a professor of anthropology at the University of Illinois at Urbana-Champaign.
The joint effort has opened up a treasure trove of data about lion prey and predators themselves.
The genetic analysis focused on mitochondrial DNA (mtDNA), which is inherited from mothers in humans and animals and can be used to trace maternal lineage. Hair stores mtDNA well and protects it from contamination, de Flamin said, and mtDNA is more abundant in cells than other types of DNA.
“We were able to obtain DNA from fragments shorter than a pinky fingernail,” de Flamin said.
The lions’ fur indicates that they share the same mitochondrial genome inherited from their mothers, supporting the previous idea that the two males are siblings. Carbis Peterhans said the presence of lion hair stuck in its teeth suggests the brothers had a close bond and groomed each other.
Researchers discovered some surprising facts when they analyzed the hair of prey eaten by lions.
The discovery of wildebeest DNA was unexpected, since the closest populations of wildebeest in the 1890s were at least 50 miles (80.5 kilometers) away. However, the Lion Brothers left Tsavo for about six months, returning in November 1898 to attack the camp again.
“This suggests that the Tsavo lion may have traveled further than previously believed, or that wildebeest may have been present in the Tsavo area at the time,” de Vlamin said.
Microscopic examination also revealed a single buffalo hair, and while buffalo is the preferred prey of the modern-day Tsavo lion, a viral rinderpest wiped out the cattle and buffalo populations in the Tsavo region in the late 1800s. I received it. The highly contagious disease has nearly wiped out cattle and their wild relatives, including the Cape buffalo, Carvis Petehans said.
“Patterson kept a handwritten field diary while he was in Tsavo,” said Carbis Petehans. “However, he did not record in his diary that he had seen any water buffalo or native cattle.”
Meanwhile, the researchers are careful and respectful of the human hair exposed during their studies, but refuse to describe or analyze it to predict ancestry or ethnicity.
“There may be descendants in this area today, and in order to practice responsible and ethical science, we are using community-based methods to extend the human side of the larger project. ” the authors state in their study. “Anthropological methods would require discussing this project with local institutions and groups as well as reporting a detailed human colonial history of this geographic region, which is beyond the scope of this study. Masu.”
Malhi said the research team plans to work with local communities to consider how to advance human hair research and genetic tracing.
Genetic techniques developed during the study can be used to study the contents of ancient carnivores’ broken teeth, potentially opening new ways to piece together the past, Malhi said.
Rav Dalen, a professor of evolutionary genomics at Stockholm University, thinks the technique is “very original.”
“We’ve known for some time that it’s possible to extract information about diet by extracting DNA from plaque on ancient teeth,” said Darren, who was not involved in the study. Ta. “But no one thought of using the hairs on the teeth of carnivores as a source of DNA.”
Microscopic studies are underway to identify more individual hairs within the lion’s teeth.
“I’m not aware of any other lion in history that has had such a diverse and long list of prey species, at least in published literature,” Gnoske said.
By analyzing the fur layers, researchers will be able to reconstruct a partial timeline of the lions’ diet and determine when they began hunting humans.
“The lower layer of the tooth cavity represents prey eaten early in life, and the upper layer of the cavity represents prey eaten more recently,” de Flamin said. “This type of analysis could provide insight into the human-lion conflicts that still affect many communities in this region and across Africa. But if they then start attacking livestock and eventually prey on humans, we can develop strategies and recommendations to reduce these risks.”
