It’s possible that I shall make an ass of myself. But in that case one can always get out of it with a little dialectic. I have, of course, so worded my proposition as to be right either way (K.Marx, Letter to F.Engels on the Indian Mutiny)
Saturday, October 12, 2024
Mitigating black carbon emissions: Key drivers in residential and coke/brick productions
Science China Press
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Figure 1Temporal trends of black carbon (BC) emissions from 37 major source types across seven sectors from 1960 to 2019 (A). Source profiles in 1962, 1995, and 2019 are shown as ring charts (B).
Black carbon (BC) is a short-lived climate forcing aerosol that can strongly absorb solar radiation, leading to climate warming. As a major component of fine particulate matter (PM2.5), BC also adversely affects human health. Multiple epidemiological studies have shown that BC is significantly more toxic than other PM components. Reducing BC emissions is crucial for mitigating global warming and improving regional air quality. However, existing BC inventories have significant uncertainties due to data limitations and other factors.
This study improved China's BC emission inventory by updating a series of activity intensity data and emission factor data from field measurements. It identified and quantified the contributions of various driving factors of major BC emission sources in China. The inventory was extended to 2019, with emission source categories refined to 146 types, a spatial resolution of 0.1°×0.1°, and a monthly temporal resolution. Benefitted from the new information and structural decomposition analysis for critical factors driving long-term variation of BC emissions in the past and coming decades, the inventory has been substantially improved and will provide stronger scientific support to policy implementation in BC pollution mitigation.
As shown in Figure 1, which presents the temporal variation in BC emissions from major sources. The total annual emission was 1.11 (0.90-1.41) Tg in 1962, increased monotonically to a peak value of 3.03 (1.92-5.15) Tg in 1995, and declined thereafter to 1.02 (0.75-1.52) Tg in 2019. In 1962, residential solid fuel combustion dominated the BC emission sources, accounting for 83.2% of the total emissions. However, by the emission peak year of 1995, the relative contribution of the residential sector had significantly declined to 34.7%, while the industrial sector’s contribution had risen from 7.8% in 1962 to 56.4% in 1995, primarily due to the substantial increase in coke (32.0%) and brick (19.5%) productions. By 2019, the most significant sources of BC emissions were coke production (18.7%), residential coal consumption (15.4%), brick kilns (12.2%), residential biomass fuels (10.8%), and diesel vehicles (8.0%). In sum, the predominant contributors were the consumption of solid fuels in the residential sector and industrial coke and brick production. These three sources accounted for 89.4%, 83.6%, and 57.4% of the total emissions in 1962, 1995, and 2019, respectively.
This study quantitatively analyzed the driving factors for the three major emission sources mentioned above. For residential emissions, the dominant negative factors were residential energy mix transition and stove switching, particularly the transition from coal and biomass fuels to cleaner energy sources. While most factors influenced both rural and urban areas in the same direction, urbanization had a positive effect in urban areas and a negative effect in rural areas, leading to slightly negative net effects on the overall trend.
In 1996, the Coal Law was enacted, and beehive coke began to be banned. Despite beehive coke accounting for only 10.1% of the total production over these 60 years, its contribution to the total BC emissions from coking reached as high as 65.3% due to its extremely high emission factors and lack of control measures. Consequently, the overall temporal trends of coke production and BC emissions exhibited notable differences. The former depended primarily on industrial-scale coke production, while beehive coke ovens predominantly governed the latter. The major drivers behind the changes in BC emissions from coke production were quantified. The key drivers include coke production, the phasing out of beehive coke ovens, and various abatement measures.
There were two general peaks in brick production, with peak years around 1995 and 2016. The significant difference in the overall temporal pattern between the productions and emissions was the relatively low emissions during the second wave. This difference was caused by reduced EFs in recent years due to brick kiln upgrading and installing end-of-pipe dust removal facilities. The positive driver was the brick production on BC emissions. The most important negative driver was the replacement of annular kilns with tunnel kilns. In comparison, dust removal had a much smaller impact on emission reduction since end-of-pipe facilities cannot effectively mitigate strong BC emissions from fugitive sources.
Figure 4 Temporal trends of brick production (A) and BC emissions from brick kilns (B) in China. Major drivers affecting BC emissions are shown as cumulative contributions(C).
Figure 3 Temporal trends in coke production (A) and BC emissions from coking (B) in China. Major drivers affecting BC emissions are also shown as accumulative contributions (C).
Severe cold-water bleaching and mortality of deep-water reef observed in the Eastern Tropical Pacific
New study highlights that deep coral ecosystems in the Eastern Pacific likely face a two-pronged threat over the 21st century: bleaching driven by the intrusion of warm water from above and by cold water from below.
Max Planck Institute for Chemistry
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Expedition diver Rose Dodwell documenting the extent of coral bleaching along a transect at 32 meters depth (white transect tape is visible in the middle of the image).
Researchers from the Max Planck Institute for Chemistry (MPIC) recently published a paper detailing their observations of a major coral bleaching and mortality event that occurred on the deep reefs of the Clipperton Atoll, a remote coral island in the Eastern Tropical Pacific. This bleaching, which was highly unexpected, is driven by the upwards displacement of cold water to much shallow depths than normal. The researchers link the presence of this anomalously shallow, cold water to changes in easterly wind strength in the Pacific, and demonstrate that the variability in wind strength can explain other past observed bleaching events of shallow reefs in the Eastern Tropical Pacific. Their study, which was recently published in the scientific journal Science of the Total Environment, highlights that cold-water bleaching may prove to be a major threat to deep reef ecosystems over the 21st century.
A disturbing surprise in the remote Eastern Pacific
Alan Foreman and Nicholas Duprey, two postdoctoral researchers from Alfredo Martínez-García’s group at the Max Planck Institute for Chemistry in Mainz, conducted a scientific expedition to Clipperton Atoll in early 2023 to collect samples from Clipperton’s shallow reefs. This work, conducted onboard the sailing yacht S/Y Acadia as part of a collaboration with the Rohr Foundation, was aimed at retrieving coral cores and water samples in an area that will allow MPIC researchers to reconstruct changes in the size of oxygen minimum zones in the Eastern Pacific over the 20th century. “Clipperton is a truly remote destination: 800 nautical miles south of Mexico and 1000 nautical miles west of Costa Rica,” explains Nicolas Duprey.
“Although we were in the area to collect other samples, serendipitously we observed bleaching on the deep coral reefs on one of our first dives,” recalls Alan. “From the temperature of the surrounding water, we were able to infer that this was almost certainly driven by the presence of cold water,” adds Nic. This was indeed quite a surprise to the two paleoclimatologists, considering that Clipperton is located in an area of the Pacific known for its warm water, with an average surface water temperature of 28°C for most of the year.
How to quantify a massive bleaching event 30 meters underwater
With assistance in the field from study coauthors Mark Rohr, Rose Dodwell, and Guy Dodwell, the two scientists began documenting the extensive bleaching present around Clipperton, both by recording the percentage of bleached and dead coral at 32 meters depth (~70 percent) and by photographing the bleaching in high resolution. With help from Matan Yuval at the University of Haifa, they merged the huge photo collection into one single image, a so-called a photomosaic, for further analysis back on dry land. When combined with temperature measurements of the upper 300 meters of the water column, it became clear that the deep corals were bleaching due to cold shock, and that this shock played a large part in was leading to substantial mortality along the deep reefs.
Assisted by Marielle Dumestre (MPIC), the researchers compiled a database of published cold- and warm-water bleaching events that occurred in the shallow reefs of the region to better elucidate the role of cold-water intrusions in governing reef ecosystem functionality. It turned out that the timing of cold-water bleaching events coincided with past maxima in easterly wind strength. “We quickly realized that this anomalously cold water so high in the water column was linked to oscillations in easterly wind strength in the Eastern Tropical Pacific,” says Alan. This link suggests that any future intensification of easterly winds in the Pacific may be a significant threat for its mesophotic coral ecosystems, as it could drive severe bleaching via increased exposure to colder waters from depth.
Mesophotic coral reefs are facing dual threats in the 21st century
Recent studies suggest that major La Niña events associated with strong easterly winds will become both stronger and more frequent in the near future. Models also predict that extreme La Niña events will follow extreme El Niño events more often. The researchers hypothesize, that, if this becomes a reality, unusually cold water will be displaced onto Eastern Tropical Pacific deep and mid-depth reefs on the heels of increased warm thermal stress from the surface. The authors of the study fear that, given the severity of bleaching and the associated coral mortality seen at Clipperton, the impact of cold-water bleaching on deep coral reefs is not transient, and that such events could strongly impact the health and functionality of a given deep-water reef.
“Our observations, in combination with recent reports of warm-water bleaching of Red Sea and Indian Ocean mesophotic coral ecosystems, highlight that 21st century mesophotic coral ecosystems in the Eastern Pacific face a two-pronged challenge: warm-water bleaching from above, and cold-water bleaching from below”, Alan concludes.
More information:
Coral Bleaching: The corals expel single-celled algae that they need to survive. As a result, they lose their color and often starve to death. Read more: https://www.mpg.de/21887931/coral-bleaching
Funding: Beyond funding by the Max Planck Society, the field expedition and research was made possible in major part by The Rohr Foundation. Other funders include the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) – Project number 468591845 – SPP 2299/Project number 441832482; the Paul Crutzen Nobel Prize Fellowship; the Leona M. and Harry B. Helmsley Charitable Trust; the Maurice Hatter Foundation; the Data Science Research Center at the University of Haifa; the Murray Foundation for student research; Microsoft AI for Earth: AI for Coral Reef Mapping.
About The Rohr Foundation and S/Y Acadia: In support of ocean conservation, S/Y Acadia hosts scientists onboard to help document the health of marine ecosystems and diversity of marine life on voyages to remote locations around the globe. Their goals are to help forge connections between people, to document the challenges we face with regard to ocean health and climate change, and to promote policy-relevant science in support of marine conservation. (More details: https://www.yachtacadia.com/)
Severe cold-water bleaching of a deep-water reef underscores future challenges for Mesophotic Coral Ecosystems, Alan D. Foreman, Nicolas N. Duprey, Matan Yuval, Marielle Dumestre, Jennifer N. Leichliter, Mark C. Rohr, Rose C.A. Dodwell, Guy A.S. Dodwell, Eric E.G. Clua, Tali Treibitz, Alfredo Martínez-García
Easily deployable multisensory collaborative tele-robotic system to inspect pipes located in radioactive environments
The prototype has been designed and built by the Interactive and Robotic Systems Lab within the EU H2020 project "El-Peacetolero"
Universitat Jaume I
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The Interactive and Robotic Systems Lab (IRS) group at the Universitat Jaume I of Castelló has developed a mobile, lightweight, modular and reconfigurable manipulator robot, which includes a remote control station with 3D perception, modular and multi-device 3D simulation software that implements a digital twin for operator training, with the aim of operating in hazardous scenarios for human health, initially in the inspection of plastic pipes by probing and artificial vision.
The Interactive and Robotic Systems Lab (IRS) group at the Universitat Jaume I of Castelló has developed a mobile, lightweight, modular and reconfigurable manipulator robot, which includes a remote control station with 3D perception, modular and multi-device 3D simulation software that implements a digital twin for operator training, with the aim of operating in hazardous scenarios for human health, initially in the inspection of plastic pipes by probing and artificial vision.
The new technology, which has been validated on an experimental scale at the UJI's Centre for Research in Robotics and Underwater Technologies (CIRTESU), is applicable to the inspection of pipes and plastic materials in the surroundings of particle accelerators and nuclear power plants, and can be adapted to support teaching or healthcare staff in other types of challenging environments, such as infectious ones.
Software enhancements include a Robot Operating System (ROS)-based server and multiple clients that can be expanded to meet specific mission requirements. Hardware enhancements include wireless communications, various vision devices, localisation techniques, mobility, low weight and power consumption, an open nature that allows modularity and adaptability, and low production costs.
The new technology, which is the result of the European project "EU H2020 El-Peacetolero" (Embedded Electronic Solutions for Polymer Innovative Scanning Methods using Light-Emitting Devices for Diagnostic Routines), in which the UJI participates along with eight other European universities and research centres, will be adapted to specific applications through specific agreements and subsequent licensing agreements with companies.
The Universitat Jaume I, through the Cooperation and Technological Development Office and the Vice-Rector's Office for Scientific Transfer, Innovation and Dissemination, facilitates the scientific and technological transfer of its research staff, with the aim of advancing its vocation to transmit and disseminate scientific, technical, social and humanistic knowledge.
Method of Research
Computational simulation/modeling
Toddlers show increased physical activity with a robot playmate moving around the room
CORVALLIS, Ore. – Parents seeking help in encouraging toddlers to be physically active may soon need to look no further than an inexpensive robotic buddy for their kids, a new study by Oregon State University suggests.
The findings are important because movement plays a key role in the overall health of children, both in youth and later on in adulthood, the authors note.
Researchers observed individual sessions for eight kids ages 2-3 once a week for two months in a playroom that included various toys as well as a toddler-sized GoBot: a custom, wheeled, foam-padded robot designed through a collaboration between the OSU colleges of Engineering and Health.
Weekly sessions with each of the five boys and three girls were broken into three segments.
During one of them, the GoBot was in the room but not active, though the child was free to push and pull the robot around if he or she wanted to.
In another, the GoBot’s movements – basically keep-away maneuvers – were directed by an operator using a PlayStation DualShock4 controller, and in the third segment type, the motion was autonomous. In either scenario, the GoBot rewarded the child for getting close to it by emitting sounds, lights or bubbles.
The results showed that kids’ activity levels, measured by multiple sensors and cameras, were higher in the presence of an active robot.
“It was interesting to us that the simple autonomous routine worked as well as directly teleoperated control when it came to engaging children,” said the College of Engineering’s Naomi Fitter, who led the study. “That means a relatively low-cost robot playmate – one that offers more intelligence and independence compared to current phone-operated robotic toys – might be feasible in the near future.”
For young children, the authors say, physical activity contributes to cognitive, social and motor development and also sets the stage for better psychosocial and cardiometabolic health later on, serving as a foundation for the potential of a lifetime of healthy habits.
“High rates of sedentary behavior are a big current challenge across many phases of life, and better physical activity at any part can lead to better health outcomes,” Fitter said.
The researchers also note that past studies indicate a significant number of children are below recommended physical activity guidelines, which contributes to high levels of childhood obesity and other negative health consequences.
“Toys that motivate crawling and assist with walking are widespread,” Fitter said, “but there’s a scarcity of toys designed to motivate young children to be active and explore their environments once they are ambulatory.”
Assistive robots like GoBot, she added, may be more effective than other tools for physical activity promotion because people tend to see robots as more “peer-like and influential” than non-embodied technologies like phones or computers.
“An important point is that we're not aiming to replace caregivers, but for parents, there can be periods of development during which it is hard to know how best to engage with your toddler,” Fitter said. “The work in our paper could lead to new robotic toys that families could play with together to help fill those gaps.”
Collaborating with Fitter were Rafael Morales Mayoral and Ameer Helmi of the College of Engineering and Samuel W. Logan of the College of Health.
Findings were published in the Journal of Translational Engineering in Health & Medicine.
Journal
IEEE Journal of Translational Engineering in Health and Medicine
Low-cost robots which can harvest and package strawberries in a matter of seconds have been trialled in Essex as part of ambitious plans to tackle a labour shortage in the industry.
The University of Essex has been working with world-famous jam makers, Wilkin & Sons, to test the new prototype, which costs a fraction of the price of existing technology.
Funded by a £1.02million grant fvia the Department for Environment, Food and Rural Affairs’ flagship Farming Innovation Programme, the project has seen the low-cost robot tasked with picking strawberries from one of Wilkins and Sons’ vertical farms in Tiptree.
The robot, which can pick a strawberry in just 2.5 seconds, is based on a previous prototype which has been successfully trialled for the last two seasons.
The modular architecture can be easily adapted to other crops – with robotic harvesting trials planned later on in the project with onions, tomatoes and lettuce.
Dr Vishwanathan Mohan and Professor Klaus McDonald-Maier, both from Essex’s School of Computer Science and Electronic Engineering, have helped design and build the robot.
Dr Mohan said: “Through this project we want to transform how food is grown efficiently using robotics and AI, and make state-of-the-art agri-robotics technologies accessible to everyone.
“Even if smaller farms and businesses can afford a robot, you need a whole fleet of them to make a difference, so it is vital we find cost-effective alternatives to help the agricultural industry.
“At the same time robotics is a game changer to tackle some of the critical challenges facing us – food security, labour security, climate and energy.”
The prototype is able to pick the strawberries using a robotic arm, before weighing each one and placing it in packaging.
It is hoped the project will not only reduce the repetitive, labour-intensive process of crop picking, but will also extend the shelf-life of produce by speeding up the packaging process.
Existing crop-picking robots cost on average around £150,000 but if successful, the new prototype will cost a fraction of the price at around £10,000.
Chris Newenham, Joint Managing Director of Wilkin & Sons, said: “Wilkin & Sons are once again delighted to partner with the University of Essex in tackling what is currently the most significant challenge for our industry.
“Our experience from our initial work with the institution is that these challenges are inordinately complex and take time, it is work which is definitely not for the faint hearted but we are confident that we are working with the very best partners and very much looking forward to seeing the fruits of our collective labours over the coming years.”
The Government’s flagship Farming Innovation Programme aims to support ambitious projects to transform productivity and enhance environmental sustainability in England’s agricultural and horticultural sectors, whilst driving the sectors towards net zero.
Dr Vishwanathan Mohan trialling the robot on the farm in Tiptree, Essex.
Credit
University of Essex
These 19th century lions from Kenya ate humans, DNA collected from hairs in their teeth shows
Cell Press
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The lions’ teeth had been damaged during their lifetimes. Study coauthor Thomas Gnoske found thousands of hairs embedded in the exposed cavities of the broken teeth.
Credit: Field Museum of Natural History in Chicago
By isolating and sequencing DNA in compacted hairs collected from the teeth of two Tsavo lion museum specimens from the 1890s, researchers have found that the historic lions from Kenya preyed on a variety of species, including humans, giraffes, and wildebeests. These so-called “Tsavo Man-Eaters” are estimated to have killed at least dozens of people, including those working along the Kenya-Uganda Railway in the late 1890’s. The findings appear in the Cell Press journal Current Biology on October 11.
“As biotechnologies advance, there are unexpected sources of knowledge, in this case genomics, that can be used to inform about the past,” says Ripan Malhi (@MalhiRipan) of the University of Illinois Urbana-Champaign. “Our results inform on the ecology and diet of lions in the past as well as on the impacts of colonization on life and land in this region of Africa.”
“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,” says Alida de Flamingh (@adeflamingh), also at the University of Illinois Urbana-Champaign. “Our analysis showed that the historic 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.”
Study co-author Tom Gnoske at the Field Museum of Natural History in Chicago was the first to consider reconstructing the diet of these historic lions using prey hairs from their skulls, the researchers say. With collaborators in Kenya, he began to identify the hairs using microscopy. While conducting ancient DNA research on other animals at the Field Museum, the University of Illinois team got the idea to add genomics as a complementary approach to the study of those compacted hairs.
The Tsavo lions in the new study 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, including giraffe, human, oryx, waterbuck, wildebeest, and zebra.
The DNA data narrowed the giraffe sample down to a subspecies of Masai giraffe from southeast Kenya. The researchers also found Tsavo lion DNA that most closely matched other East African lions from Kenya and Tanzania. The researchers said they were most surprised to find hair from wildebeest, noting that it raises questions about their distribution in the past.
“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,” de Flamingh said. “The closest grazing area for wildebeest was over 50 miles from where the lions were killed in 1898 at the Tsavo-Athi confluence.”
The researchers say they are excited to explore the findings in even greater detail. For example, they suggest that the layered hairs can allow them to go back in time to reconstruct the lions’ diet at different ages. They suggest that such analysis may offer insight into human-lion conflicts that continue to impact communities in Africa, where lions may prey on wildlife as well as domestic animals and humans. The method also holds promise for studies of even older specimens.
“This methodology can potentially be used on hairs from broken teeth of more ancient carnivores from hundreds to thousands of years ago,” Malhi said. “The method opens up a new avenue of inquiry into the past.”
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This work was supported by the US Department of Agriculture, USAID, and the University of Illinois Urbana-Champaign.
Current Biology (@CurrentBiology), published by Cell Press, is a bimonthly journal that features papers across all areas of biology. Current Biology strives to foster communication across fields of biology, both by publishing important findings of general interest and through highly accessible front matter for non-specialists. Visit http://www.cell.com/current-biology. To receive Cell Press media alerts, contact press@cell.com.
Credit: Photo copyright Michael Jeffords and Susan Post
CHAMPAIGN, Ill. — In 1898, two male lions terrorized an encampment of bridge builders on the Tsavo River in Kenya. The lions, which were massive and maneless, crept into the camp at night, raided the tents and dragged off their victims. The infamous Tsavo “man-eaters” killed at least 28 people before Lt. Col. John Henry Patterson, the civil engineer on the project, shot them dead. Patterson sold the lions’ remains to the Field Museum of Natural History in Chicago in 1925.
In a new study, Field Museum researchers collaborated 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 microscopy and genomics to identify some of the species the lions consumed. The findings are reported in the journal Current Biology.
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 consumed. He was the first to determine that they were fully grown older adult males — despite being maneless. He also was the first to notice that thousands of broken and compacted hairs had accumulated in exposed cavities in the lions’ damaged teeth during their lifetimes.
In 2001, Gnoske and Julian Kerbis Peterhans, a professor at Roosevelt University and Field Museum adjunct curator, first reported on the damaged condition of the teeth — which they hypothesized may have contributed to the lions’ predation of humans — and the presence of hairs embedded in broken and partially healed teeth. A preliminary analysis of some of the hairs suggested that they were from eland, impala, oryx, porcupine, warthog and zebra.
In the new study, Gnoske and Peterhans facilitated a new examination of some of the hairs. Co-authors Ogeto Mwebi, a senior research scientist at the National Museums of Kenya; and Nduhiu Gitahi, a researcher at the University of Nairobi, conducted the microscopic analysis of the hairs. U. of I. postdoctoral researcher Alida de Flamingh led a genomic investigation of the hairs with U. of I. anthropology professor Ripan S. Malhi. They focused on a separate sample of four individual hairs and three clumps of hairs extracted from the lions’ teeth.
Malhi, de Flamingh and their colleagues are developing new techniques to learn about the past by sequencing and analyzing ancient DNA preserved in biological artifacts. Their work in partnership with Indigenous communities has yielded numerous insights into human migration and the pre- and postcolonial history of the Americas. They have helped develop tools for determining the species and geographic origins of present-day and ancient tusks of African elephants. They have advanced efforts to isolate and sequence DNA from museum specimens and have traced the migration and genomic history of dogs in the Americas.
In the current work, de Flamingh first looked for, and found, familiar hallmarks of age-related degradation in what remained of the nuclear DNA in the hairs from the lions’ teeth.
“To establish the authenticity of the sample we’re analyzing, we look to see whether the DNA has these patterns that are typically found in ancient DNA,” she said.
Once the samples were authenticated, 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 matrilineal lineages through time.
There are several advantages to focusing on mtDNA in hair, the researchers said. Previous studies have found that hair structure preserves mtDNA and protects it from external contamination. MtDNA also is much more abundant than nuclear DNA in cells.
“And because the mitochondrial genome is much smaller than the nuclear genome, it’s easier to reconstruct in potential prey species,” de Flamingh said.
The team built a database of mtDNA profiles of potential prey species. This reference database was compared with mtDNA profiles obtained from the hairs. The researchers took into account the species suggested in the earlier analysis and those known to be present in Tsavo at the time the lions were alive.
The researchers also developed methods for extracting and analyzing the mtDNA from the hair fragments.
“We were even able to get DNA from fragments that were shorter than the nail on your pinky finger,” de Flamingh said.
“Traditionally, when people want to get DNA from hairs, they’ll focus on the follicle, which is going to have a lot of nuclear DNA in it,” Malhi said. “But these were fragments of hair shafts that were more than 100 years old.”
The effort yielded a treasure trove of information.
“Analysis of hair DNA identified giraffe, human, oryx, waterbuck, wildebeest and zebra as prey, and also identified hairs that originated from lions,” the researchers reported.
The lions were found to share the same maternally inherited mitochondrial genome, supporting early reports theorizing that they were siblings. Their mtDNA also was consistent with an origin in Kenya or Tanzania.
The team found that the lions had consumed at least two giraffes, along with a zebra that likely originated in the Tsavo region.
The discovery of wildebeest mtDNA was surprising because the nearest population of wildebeests in the late 1890s was about 50 miles away, the researchers said. Historical reports, however, noted that the lions left the Tsavo region for about six months before resuming their rampage on the bridge-builders’ camp.
The absence of buffalo DNA and the presence of only a single buffalo hair — identified using microscopy — was surprising, de Flamingh said. “We know from what lions in Tsavo eat today that buffalo is the preferred prey,” she said.
“Colonel Patterson kept a handwritten field journal during his time at Tsavo,” Kerbis Peterhans said. “But he never recorded seeing buffalo or indigenous cattle in his journal.”
At the time, the cattle and buffalo populations in this part of Africa were devastated by rinderpest, a highly contagious viral disease brought to Africa from India by the early 1880s, Kerbis Peterhans 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.
“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,” they wrote.
The new findings are an important expansion of the kinds of data that can be extracted from skulls and hairs from the past, the researchers said.
“Now we know that we can reconstruct complete mitochondrial genomes from single hair fragments from lions that are more than 100 years old,” de Flamingh said.
There were thousands of hairs embedded in the lions’ teeth, compacted over a period of years, the researchers said. Further analyses will allow the scientists to at least partially reconstruct the lions’ diet over time and perhaps pinpoint when their habit of preying on humans began.
The National Science Foundation and U.S. Department of Agriculture supported this research.
A genomic study of the maneless Tsavo lions confirmed that they were likely siblings. Pictured: a pair of maneless lions living today in the Tsavo region.
The lions’ teeth were damaged during their lifetimes. Study co-author Thomas Gnoske found thousands of hairs embedded in the exposed cavities of the broken teeth.
Credit
Photo Z94320 courtesy Field Museum of Natural History in Chicago
Hairs embedded in the lions’ teeth included those of zebra, top, and wildebeest, bottom.
The study also identified hairs from two giraffes in the lions’ teeth.
Credit
Painting copyright Velizar Simeonovski, 2024
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In the 1990s, a team from the Kenya Wildlife Service and the Field Museum of Natural History in Chicago found a cave that the “man-eater” lions had used in Tsavo, Kenya. The team included Thomas Gnoske, front row, far left; Julian Kerbis Peterhans, front row, far right; and Samuel Andanje, back row, second from left, a KWS research biologist who, with Gnoske and Kerbis Peterhans, coordinated the search for the cave.
