Tag: Bonnie F. Jacobs

Categories
Earth & Climate Fossils & Ruins Plants & Animals Student researchers Subfeature

Prehistoric puzzle settled: carbon dioxide link to global warming 22 million years ago

The modern link between high carbon dioxide levels and climate change didn’t appear to hold true for a time interval about 22 million years ago; but now a new study has found the link does indeed exist.

Fossil leaves from Africa have resolved a prehistoric climate puzzle — and also confirm the link between carbon dioxide in the atmosphere and global warming.

Research until now has produced a variety of results and conflicting data that have cast doubt on the link between high carbon dioxide levels and climate change for a time interval about 22 million years ago.

But a new study has found the link does indeed exist for that prehistoric time period, say researchers at Southern Methodist University, Dallas.

The finding will help scientists understand how recent and future increases in the concentration of atmospheric carbon dioxide may impact the future of our planet, say the SMU researchers.

The discovery comes from new biochemical analyses of fossil leaves from plants that grew on Earth 27 million years ago and 22 million years ago, said geologist Tekie Tesfamichael, lead scientist on the research.

The new analyses confirm research about modern climate — that global temperatures rise and fall with increases and decreases in carbon dioxide in our atmosphere — but in this case even in prehistoric times, according to the SMU-led international research team.

Carbon dioxide is a gas that is normally present in the Earth’s atmosphere, even millions of years ago. It’s dubbed a greenhouse gas because greater concentrations cause the overall temperature of Earth’s atmosphere to rise, as happens in a greenhouse with lots of sunlight.

Recently greenhouse gas increases have caused global warming, which is melting glaciers, sparking extreme weather variability and causing sea levels to rise.

The new SMU discovery that carbon dioxide behaved in the same manner millions of years ago that it does today has significant implications for the future. The finding suggests the pairing of carbon dioxide and global warming that is seen today also holds true for the future if carbon dioxide levels continue to rise as they have been, said Tesfamichael.

“The more we understand about the relationship between atmospheric carbon dioxide concentrations and global temperature in the past, the more we can plan for changes ahead,” said Tesfamichael, an SMU postdoctoral fellow in Earth Sciences.

“Previous work reported a variety of results and conflicting data about carbon dioxide concentrations at the two intervals of time that we studied,” he said. “But tighter control on the age of our fossils helped us to address whether or not atmospheric carbon dioxide concentration corresponded to warming — which itself is independently well-documented in geochemical studies of marine fossils in ocean sediments.”

The researchers reported their findings in Geology, the scientific journal of the Geological Society of America. The article is “Settling the issue of ‘decoupling’ between atmospheric carbon dioxide and global temperature: [CO2]atm reconstructions across the warming Paleogene-Neogene divide.”

Co-authors from the Roy M. Huffington Department of Earth Sciences in Dedman College are professors Bonnie Jacobs, an expert in paleobotany and paleoclimate, and Neil J. Tabor, an expert in sedimentology and sedimentary geochemistry.

Other co-authors are Lauren Michel, Tennessee Technological University; Ellen Currano, University of Wyoming; Mulugeta Feseha, Addis Ababa University; Richard Barclay, Smithsonian Institution; John Kappelman, University of Texas; and Mark Schmitz, Boise State University.

Discovery of rare, well-preserved fossil leaves enables finding
The findings were possible thanks to the rare discovery of two sites with extraordinarily well-preserved fossil leaves of flowering plants from the Ethiopian Highlands of eastern Africa.

Such well-preserved fossil leaves are a rarity, Tesfamichael said.

“Finding two sites with great preservation in the same geographic region from two important time intervals was very fortunate, as this enabled us to address the question we had about the relationship between atmospheric carbon dioxide concentration and global temperatures,” he said.

Scientists know that variations in the concentration of atmospheric carbon dioxide affect carbon fixation in leaves during photosynthesis. This causes leaves to develop anatomical and physiological changes such as the frequency and size of stomata — the pores on the surface of a leaf through which carbon passes.

Scientists can measure those attributes, among others, in fossil leaves, so that leaf fossils can be used as proxies for Earth’s atmospheric carbon dioxide history.

The sites producing the leaves for the SMU study were discovered separately in years past, but major fossil collections were produced through field work coordinated by the SMU research team and their co-authors, who have been collaborating on this project for several years.

The work has had funding from the National Science Foundation, The National Geographic Committee for Research and Exploration, the SMU Ford Fellowship Program, SMU Research Council, the Institute for the Study of Earth and Man, and the Dallas Paleontological Society Frank Crane Scholarship.

The fossils are housed permanently in the collections at the National Museum of Ethiopia in Addis Ababa. Institutional and governmental support came from the National Museum of Ethiopia, the Authority for Research and Conservation of Cultural Heritage, and Addis Ababa University.

Previous studies firmly established a temperature difference
One of the sites dates to the late Oligocene Epoch, and the other to the early Miocene.

Previous studies that measured ocean temperatures from around the world for the two intervals have firmly established a temperature difference on Earth between the two times, with one much warmer than the other. So the SMU study sought to measure the levels of carbon dioxide for the two time periods.

For the SMU analyses, fossil leaves of a single species were collected from the 27 million-year-old late Oligocene site. The leaves had been deposited during prehistoric times in the area of Chilga in northwest Ethiopia most likely at a river bank. The Earth’s climate during the late Oligocene may have been somewhat warmer than today, although glaciers were forming on Antarctica. The SMU study found carbon dioxide levels, on average, around 390 parts per million, about what it is on Earth today.

Fossil leaves of the 22 million-year-old species from the early Miocene were collected from ancient lake deposits, now a rock called shale, from the modern-day Mush Valley in central Ethiopia. The early Miocene climate at that time was warmer than the late Oligocene and likewise the SMU study found higher carbon dioxide levels. Atmospheric carbon dioxide was about 870 parts per million, double what it is on Earth today.

The SMU study confirmed a relationship between carbon dioxide and temperature during the late Oligocene and early Miocene.

Paleoclimate data can help predict our planet’s future climate
While carbon dioxide isn’t the only factor affecting Earth’s climate or global mean temperature, it is widely considered by scientists among the most significant. Much is known about climate change and global warming, but questions still remain.

“One of those is ‘What’s the sensitivity of the Earth’s temperature to carbon dioxide concentration? Is it very sensitive? Is it not so sensitive?’ Estimating temperature and carbon dioxide concentrations for times in the past can help find the answer to that question,” Jacobs said. “There’s a lot of work on paleoclimate in general, but not as much on the relationship between carbon dioxide and temperature.”

The finding is an important one.

“The amount of temperature change during this interval is approximately within the range of the temperature change that is estimated from climate models for our next century given a doubling of carbon dioxide concentration since the industrial revolution,” Jacobs said.

With the new model reaffirming the prehistoric relationship, scientists can look now at related questions, said climate change scientist Lauren Michel, who worked on the study as a post-doctoral researcher at SMU.

“Answering questions about the rate of change and which factors changed first, for example, will ultimately give a clearer picture of the Earth’s climate change patterns,” Michel said. “I think it is valuable to understand the relationship of greenhouse gases and climate factors represented in the rock record so we can have a better idea of what we can expect in the future and how we can prepare for that.”

SMU study confirms relationship that previous methods overlooked
Previous studies found little to no correlation between temperature and carbon dioxide for the late Oligocene and early Miocene. That has puzzled paleoclimate researchers for at least a decade.

“We have a good test-case scenario with these well-preserved plants from both time slices, where we know one time slice, with higher levels of carbon dioxide, was a warmer climate globally than the other,” Tesfamichael said.

“It’s been a puzzle as to why the previous methods found no relationship, or an inverse correlation,” he said. “We think it’s for lack of the well-dated proxy — such as our fossil leaves from two precise times in the same region — which deliver a reliable answer. Or, perhaps the models themselves needed improvement.”

Previous studies used methodologies that differed from the SMU study, although all methods (proxies) incorporate some aspects of what is known about living organisms and how they interact with atmospheric carbon dioxide.

Some studies rely on biochemical modeling of the relationship between single-celled marine fossils and atmospheric carbon dioxide, and others rely on the relationship between stomata and atmospheric carbon dioxide concentration observed in the living relatives of particular fossil plant species.

“Each method has its assumptions,” said Tesfamichael. “We will see if our results hold up with further studies of this time interval using the same methodology we used.” — Margaret Allen, SMU

Categories
Earth & Climate Fossils & Ruins Plants & Animals Researcher news SMU In The News

Australian Geographic: Secrets of leaf size revealed

New findings reveal the real reasons behind varying leaf sizes.

Australian Geographic has covered the research of SMU paleobotanist Bonnie F. Jacobs, a professor in SMU’s Roy M. Huffington Department of Earth Sciences.

Working with a global team of researchers, Jacobs and her colleagues cracked the mystery of leaf size. The research was published Sept. 1, 2017 as a cover story in Science.

The researchers from Australia, the U.K., Canada, Argentina, the United States, Estonia, Spain and China analyzed leaves from more than 7,600 species of plants over the past 20 years, then pooled and analyzed the data with new theory to create a series of equations that can predict the maximum viable leaf size anywhere in the world based on the risk of daytime overheating and night-time freezing.

The researchers will use these findings to create more accurate vegetation models. This will be used by governments to predict how vegetation will change locally and globally under climate change, and to plan for adaptation.

Jacobs contributed an extensive leaf database — research that was funded by a National Science Foundation grant. She analyzed the leaf characteristics of 880 species of modern tropical African plants, which occurred in various combinations among 30 plant communities. Jacobs measured leaves of the plant specimens at the Missouri Botanical Garden Herbarium, one of the largest archives of pressed dried plant specimens from around the world.

Jacobs is one of a handful of the world’s experts on the fossil plants of ancient Africa. As part of a team of paleontologists working there, she hunts plant and animal fossils in Ethiopia’s prolific Mush Valley, as well as elsewhere in Africa.

Read the full story.

EXCERPT:

By Karl Gruber
Australian Geographic
You may have learnt at school that leaf size depends on water availability and that they are meant to help plants avoid overheating. But a new study that looked at leaf sizes around the world found that, rather than water availability, it all boils down to temperature, both high and low.

Leaf sizes can vary by as much as 100,000 fold, with some leaves having an area of just 1 mm2 while other can have an area of up to 1 m2. But what is driving these big differences?

“The conventional explanation was that water availability and overheating were the two major limits to leaf size. But the data didn’t fit,” says Ian. “For example the tropics are both wet and hot, and leaves in cooler parts of the world are unlikely to overheat,” explained Ian Wright, from Macquarie University, who led the new study.

A key finding from the study is that for plants all around the world the main factors limiting leaf size are the risk of frosting in cold nights, which can damage leaves, and the risk of overheating during the day.

“Latitude explains 28% of variation leaf size, globally. Warm wet regions are characterised by large-leaved species, warm dry regions and cold regions by smaller-leaved species. These patterns can all be understood in relation to the energy inputs and outputs to leaves, but only if you consider both the daytime (overheating) and night-time (freezing) risks,” Wright says.

Read the full story.

Categories
Earth & Climate Fossils & Ruins Plants & Animals Researcher news SMU In The News

BBC: Clues to why leaves come in many sizes

The huge variety of leaves in the plant kingdom has long been a source of wonder and fascination.

BBC News has covered the research of SMU paleobotanist Bonnie F. Jacobs, a professor in SMU’s Roy M. Huffington Department of Earth Sciences.

Working with a global team of researchers, Jacobs and her colleagues cracked the mystery of leaf size. The research was published Sept. 1, 2017 as a cover story in Science.

The researchers from Australia, the U.K., Canada, Argentina, the United States, Estonia, Spain and China analyzed leaves from more than 7,600 species of plants over the past 20 years, then pooled and analyzed the data with new theory to create a series of equations that can predict the maximum viable leaf size anywhere in the world based on the risk of daytime overheating and night-time freezing.

The researchers will use these findings to create more accurate vegetation models. This will be used by governments to predict how vegetation will change locally and globally under climate change, and to plan for adaptation.

Jacobs contributed an extensive leaf database — research that was funded by a National Science Foundation grant. She analyzed the leaf characteristics of 880 species of modern tropical African plants, which occurred in various combinations among 30 plant communities. Jacobs measured leaves of the plant specimens at the Missouri Botanical Garden Herbarium, one of the largest archives of pressed dried plant specimens from around the world.

Jacobs is one of a handful of the world’s experts on the fossil plants of ancient Africa. As part of a team of paleontologists working there, she hunts plant and animal fossils in Ethiopia’s prolific Mush Valley, as well as elsewhere in Africa.

Read the full story.

EXCERPT:

By Helen Briggs
BBC News
The leaves of a banana plant, for instance, are about a million times bigger than the leaves of heather.

The conventional wisdom is that leaf size is limited by the balance between how much water is available to a plant and the risk of overheating.

However, a study of more than 7,000 plant species around the world suggests the answer may be more complex.

“A banana leaf is able to be so huge because bananas naturally grow in places that are very hot and very wet,” said Ian Wright of Macquarie University in Sydney, Australia.
“Our work shows that in fact that if there’s enough water in the soil then there’s almost no limit to how large leaves can be.”

He says this is only part of the puzzle of leaf size.

“The other part is about the tendency for larger leaves to freeze at night,” Dr Wright explained.

“And, you put these two ingredients together — the risk of freezing and the risk of overheating — and this helps understand the pattern of leaf sizes you see across the entire world.”

There are hundreds of thousands of plant species on the planet, from tiny alpine plants to massive jungle palms.

Their leaves vary in area from less than 1 square millimetre to greater than 1 square metre.

Large-leaved plants predominate in tropical jungle — something that was noted as early as the 19th Century. Meanwhile, small-leaved plants thrive in arid deserts and at high latitudes.

Some decades ago, scientists realised that variability in leaf size was related to water and temperature. They proposed that the limit to leaf size was set by the risk of overheating.

Thus, when rainfall is high, plants can get away with having larger leaves.
The new research, published in the journal Science, suggests this idea applies only in certain regions of the globe.

“There were some pieces in this puzzle that were clearly missing,” Dr. Wright told BBC News.

Read the full story.

Categories
Earth & Climate Feature Fossils & Ruins Plants & Animals Researcher news

The mystery of leaf size solved by global team of scientists

A global team of researchers, including SMU paleobotanist Bonnie Jacobs, have cracked the mystery of leaf size. The research was published Sept. 1, 2017 as a cover story in Science.

SMU paleobotanist Bonnie F. Jacobs has contributed research to a major new study that provides scientists with a new tool for understanding both ancient and future climate by looking at the size of plant leaves.

Why is a banana leaf a million times bigger than a common heather leaf? Why are leaves generally much larger in tropical jungles than in temperate forests and deserts? The textbooks say it’s a balance between water availability and overheating.

But it’s not that simple, the researchers found.

The study, published in the Sept. 1, 2017 issue of Science, was led by Associate Professor Ian Wright from Macquarie University, Australia. The study’s findings reveal that in much of the world the key factor limiting the size of a plant’s leaves is the temperature at night and the risk of frost damage to leaves.

Jacobs said the implications of the study are significant for enabling scientists to either predict modern leaf size in the distant future, or to understand the climate for a locality as it may have been in the past.

“This research provides scientists with another tool for predicting future changes in vegetation, given climate change, and for describing ancient climate given fossil leaves,” said Jacobs, a professor in SMU’s Roy M. Huffington Department of Earth Sciences in the Dedman College of Humanities and Sciences.

“Now we can reliably use this as another way to look at future climate models for a specific location and predict the size of plant leaves,” she said. “Or, if we’re trying to understand what the climate was for a prehistoric site tens of millions of years ago, we can look at the plant fossils discovered in that location and describe what the climate most likely was at that time.”

Wright, Jacobs and 15 colleagues from Australia, the U.K., Canada, Argentina, the United States, Estonia, Spain and China analyzed leaves from more than 7,600 species, then pooled and analyzed the data with new theory to create a series of equations that can predict the maximum viable leaf size anywhere in the world based on the risk of daytime overheating and night-time freezing.

The researchers will use these findings to create more accurate vegetation models. This will be used by governments to predict how vegetation will change locally and globally under climate change, and to plan for adaptation.

Big data solves century-old conundrum
The iconic paintings of Henri Rousseau illustrate that when we think of steamy tropics we expect large leaves. But for scientists it’s been a century-old conundrum: why does leaf size vary with latitude – from very small near the poles to massive leaves in the tropics?

“The conventional explanation was that water availability and overheating were the two major limits to leaf size. But the data didn’t fit,” says Wright. “For example the tropics are both wet and hot, and leaves in cooler parts of the world are unlikely to overheat.”

“Our team worked both ends of the problem – observation and theory,” he says. “We used big data – measurements made on tens of thousands of leaves. By sampling across all continents, climate zones and plant types we were able to show that simple ‘rules’ seemingly operate across the world’s plant species, rules that were not apparent from previous, more limited analyses.”

Jacobs contributed an extensive leaf database she compiled about 20 years ago, funded by a National Science Foundation grant. She analyzed the leaf characteristics of 880 species of modern tropical African plants, which occurred in various combinations among 30 plant communities. Jacobs measured leaves of the plant specimens at the Missouri Botanical Garden Herbarium, one of the largest archives of pressed dried plant specimens from around the world.

She looked at all aspects of leaf shape and climate, ranging from seasonal and annual rainfall and temperature for each locale, as well as leaf shape, size, tip, base, among others. Using statistical analyses to plot the variables, she found the most prominent relationship between leaf shape and climate was that size increases with rainfall amount. Wet sites had species with larger leaves than dry sites.

Her Africa database was added to those of many other scientists who have compiled similar data for other localities around the world.

Threat of night time frost damage determines the size of a leaf
“Using our knowledge of plant function and biophysics we developed a fresh take on ‘leaf energy balance’ theory, and compared our predictions to observed leaf sizes,” Wright says.

“The most surprising result was that over much of the world the maximum size of leaves is set not by the risk of overheating, but rather by the risk of damaging frost at night. Larger leaves have thicker, insulating ‘boundary layers’ of still air that slows their ability to draw heat from their surroundings – heat that is needed to compensate for longwave energy lost to the night-time sky,” says co-author Colin Prentice from Imperial College London, who co-ordinated the mathematical modelling effort.

“International collaborations are making ecology into a predictive science at global scale,” says Emeritus Professor Mark Westoby. “At Macquarie University we’re proud to have led this networking over the past 20 years.” — Margaret Allen, SMU, and Macquarie University

By Ian Wright
Macquarie University
As a plant ecologist, I try to understand variation in plant traits (the physical, chemical and physiological properties of their tissues) and how this variation affects plant function in different ecosystems.

For this study I worked with 16 colleagues from Australia, the UK, Canada, Argentina, the US, Estonia, Spain and China to analyse leaves from more than 7,600 species. We then teamed the data with new theory to create a model that can predict the maximum viable leaf size anywhere in the world, based on the dual risks of daytime overheating and night-time freezing.

These findings will be used to improve global vegetation models, which are used to predict how vegetation will change under climate change, and also to better understand past climates from leaf fossils.

From giants to dwarfs
The world’s plant species vary enormously in the typical size of their leaves; from 1 square millimetre in desert species such as common eutaxia (Eutaxia microphylla), or in common heather (Calluna vulgaris) in Europe, to as much as 1 square metre in tropical species like Musa textilis, the Filipino banana tree.

But what is the physiological or ecological significance of all this variation in leaf size? How does it affect the way that plants “do business”, using leaves as protein-rich factories that trade water (transpiration) for carbon (photosynthesis), powered by energy from the sun?

More than a century ago, early plant ecologists such as Eugenius Warming argued that it was the high rainfall in the tropics that allowed large-leaved species to flourish there.

In the 1960s and ‘70s physicists and physiologists tackled the problem, showing that in mid-summer large leaves are more prone to overheating, requiring higher rates of “transpirational cooling” (a process akin to sweating) to avoid damage. This explained why many desert species have small leaves, and why species growing in cool, shaded understoreys (below the tree canopy) can have large leaves.

But still there were missing pieces to this puzzle. For example, the tropics are both wet and hot, and these theories predicted disadvantages for large-leafed species in hot regions. And, in any case, overheating must surely be unlikely for leaves in many cooler parts of the world.

Our research aimed to find these missing pieces. By collecting samples from all continents, climate zones and plant types, our team found simple “rules” that appear to apply to all of the world’s plant species – rules that were not apparent from previous, more limited analyses.

We found the key factors are day and night temperatures, rainfall and solar radiation (largely determined by distance from the Equator and the amount of cloud cover). The interaction of these factors means that in hot and sunny regions that are also very dry, most species have small leaves, but in hot or sunny regions that receive high rainfall, many species have large leaves. Finally, in very cold regions (e.g. at high elevation, or at high northern latitudes), most species have small leaves.

But the most surprising results emerged from teaming the new theory for leaf size, leaf temperature and water use with the global data analyses, to investigate what sets the maximum size of leaves possible at any point on the globe.

Read the author’s full essay

Categories
Culture, Society & Family Earth & Climate Economics & Statistics Energy & Matter Events Fossils & Ruins Health & Medicine Learning & Education Mind & Brain Plants & Animals Researcher news Student researchers

SMU 2015 research efforts broadly noted in a variety of ways for world-changing impact

SMU scientists and their research have a global reach that is frequently noted, beyond peer publications and media mentions.

By Margaret Allen
SMU News & Communications
It was a good year for SMU faculty and student research efforts. Here is a small sampling of public and published acknowledgements during 2015:

Simmons, Diego Roman, SMU, education

Hot topic merits open access
Taylor & Francis, publisher of the online journal Environmental Education Research, lifted its subscription-only requirement to meet demand for an article on how climate change is taught to middle-schoolers in California.

Co-author of the research was Diego Román, assistant professor in the Department of Teaching and Learning, Annette Caldwell Simmons School of Education and Human Development.

Román’s research revealed that California textbooks are teaching sixth graders that climate change is a controversial debate stemming from differing opinions, rather than a scientific conclusion based on rigorous scientific evidence.

The article, “Textbooks of doubt: Using systemic functional analysis to explore the framing of climate change in middle-school science textbooks,” published in September. The finding generated such strong interest that Taylor & Francis opened access to the article.

bichaw_v054i049.indd

Research makes the cover of Biochemistry
Drugs important in the battle against cancer were tested in a virtual lab by SMU biology professors to see how they would behave in the human cell.

A computer-generated composite image of the simulation made the Dec. 15 cover of the journal Biochemistry.

Scientific articles about discoveries from the simulation were also published in the peer review journals Biochemistry and in Pharmacology Research & Perspectives.

The researchers tested the drugs by simulating their interaction in a computer-generated model of one of the cell’s key molecular pumps — the protein P-glycoprotein, or P-gp. Outcomes of interest were then tested in the Wise-Vogel wet lab.

The ongoing research is the work of biochemists John Wise, associate professor, and Pia Vogel, professor and director of the SMU Center for Drug Discovery, Design and Delivery in Dedman College. Assisting them were a team of SMU graduate and undergraduate students.

The researchers developed the model to overcome the problem of relying on traditional static images for the structure of P-gp. The simulation makes it possible for researchers to dock nearly any drug in the protein and see how it behaves, then test those of interest in an actual lab.

To date, the researchers have run millions of compounds through the pump and have discovered some that are promising for development into pharmaceutical drugs to battle cancer.

Click here to read more about the research.

SMU, Simpson Rowe, sexual assault, video

Strong interest in research on sexual victimization
Teen girls were less likely to report being sexually victimized after learning to assertively resist unwanted sexual overtures and after practicing resistance in a realistic virtual environment, according to three professors from the SMU Department of Psychology.

The finding was reported in Behavior Therapy. The article was one of the psychology journal’s most heavily shared and mentioned articles across social media, blogs and news outlets during 2015, the publisher announced.

The study was the work of Dedman College faculty Lorelei Simpson Rowe, associate professor and Psychology Department graduate program co-director; Ernest Jouriles, professor; and Renee McDonald, SMU associate dean for research and academic affairs.

The journal’s publisher, Elsevier, temporarily has lifted its subscription requirement on the article, “Reducing Sexual Victimization Among Adolescent Girls: A Randomized Controlled Pilot Trial of My Voice, My Choice,” and has opened it to free access for three months.

Click here to read more about the research.

Consumers assume bigger price equals better quality
Even when competing firms can credibly disclose the positive attributes of their products to buyers, they may not do so.

Instead, they find it more lucrative to “signal” quality through the prices they charge, typically working on the assumption that shoppers think a high price indicates high quality. The resulting high prices hurt buyers, and may create a case for mandatory disclosure of quality through public policy.

That was a finding of the research of Dedman College’s Santanu Roy, professor, Department of Economics. Roy’s article about the research was published in February in one of the blue-ribbon journals, and the oldest, in the field, The Economic Journal.

Published by the U.K.’s Royal Economic Society, The Economic Journal is one of the founding journals of modern economics. The journal issued a media briefing about the paper, “Competition, Disclosure and Signaling,” typically reserved for academic papers of broad public interest.

The Journal of Physical Chemistry A

Chemistry research group edits special issue
Chemistry professors Dieter Cremer and Elfi Kraka, who lead SMU’s Computational and Theoretical Chemistry Group, were guest editors of a special issue of the prestigious Journal of Physical Chemistry. The issue published in March.

The Computational and Theoretical research group, called CATCO for short, is a union of computational and theoretical chemistry scientists at SMU. Their focus is research in computational chemistry, educating and training graduate and undergraduate students, disseminating and explaining results of their research to the broader public, and programming computers for the calculation of molecules and molecular aggregates.

The special issue of Physical Chemistry included 40 contributions from participants of a four-day conference in Dallas in March 2014 that was hosted by CATCO. The 25th Austin Symposium drew 108 participants from 22 different countries who, combined, presented eight plenary talks, 60 lectures and about 40 posters.

CATCO presented its research with contributions from Cremer and Kraka, as well as Marek Freindorf, research assistant professor; Wenli Zou, visiting professor; Robert Kalescky, post-doctoral fellow; and graduate students Alan Humason, Thomas Sexton, Dani Setlawan and Vytor Oliveira.

There have been more than 75 graduate students and research associates working in the CATCO group, which originally was formed at the University of Cologne, Germany, before moving to SMU in 2009.

519ca82d-6517-4df9-b5ac-26e5458882ef

Vertebrate paleontology recognized with proclamation
Dallas Mayor Mike Rawlings proclaimed Oct. 11-17, 2015 Vertebrate Paleontology week in Dallas on behalf of the Dallas City Council.

The proclamation honored the 75th Annual Meeting of the Society of Vertebrate Paleontology, which was jointly hosted by SMU’s Roy M. Huffington Department of Earth Sciences in Dedman College and the Perot Museum of Science and Nature. The conference drew to Dallas some 1,200 scientists from around the world.

Making research presentations or presenting research posters were: faculty members Bonnie Jacobs, Louis Jacobs, Michael Polcyn, Neil Tabor and Dale Winkler; adjunct research assistant professor Alisa Winkler; research staff member Kurt Ferguson; post-doctoral researchers T. Scott Myers and Lauren Michael; and graduate students Matthew Clemens, John Graf, Gary Johnson and Kate Andrzejewski.

The host committee co-chairs were Anthony Fiorillo, adjunct research professor; and Louis Jacobs, professor. Committee members included Polcyn; Christopher Strganac, graduate student; Diana Vineyard, research associate; and research professor Dale Winkler.

KERA radio reporter Kat Chow filed a report from the conference, explaining to listeners the science of vertebrate paleontology, which exposes the past, present and future of life on earth by studying fossils of animals that had backbones.

SMU earthquake scientists rock scientific journal

Modelled pressure changes caused by injection and production. (Nature Communications/SMU)
Modelled pressure changes caused by injection and production. (Nature Communications/SMU)

Findings by the SMU earthquake team reverberated across the nation with publication of their scientific article in the prestigious British interdisciplinary journal Nature, ranked as one of the world’s most cited scientific journals.

The article reported that the SMU-led seismology team found that high volumes of wastewater injection combined with saltwater extraction from natural gas wells is the most likely cause of unusually frequent earthquakes occurring in the Dallas-Fort Worth area near the small community of Azle.

The research was the work of Dedman College faculty Matthew Hornbach, associate professor of geophysics; Heather DeShon, associate professor of geophysics; Brian Stump, SMU Albritton Chair in Earth Sciences; Chris Hayward, research staff and director geophysics research program; and Beatrice Magnani, associate professor of geophysics.

The article, “Causal factors for seismicity near Azle, Texas,” published online in late April. Already the article has been downloaded nearly 6,000 times, and heavily shared on both social and conventional media. The article has achieved a ranking of 270, which puts it in the 99th percentile of 144,972 tracked articles of a similar age in all journals, and 98th percentile of 626 tracked articles of a similar age in Nature.

“It has a very high impact factor for an article of its age,” said Robert Gregory, professor and chair, SMU Earth Sciences Department.

The scientific article also was entered into the record for public hearings both at the Texas Railroad Commission and the Texas House Subcommittee on Seismic Activity.

Researchers settle long-debated heritage question of “The Ancient One”

The skull of Kennewick Man and a sculpted bust by StudioEIS based on forensic facial reconstruction by sculptor Amanda Danning. (Credit: Brittany Tatchell)
The skull of Kennewick Man and a sculpted bust by StudioEIS based on forensic facial reconstruction by sculptor Amanda Danning. (Credit: Brittany Tatchell)

The research of Dedman College anthropologist and Henderson-Morrison Professor of Prehistory David Meltzer played a role in settling the long-debated and highly controversial heritage of “Kennewick Man.”

Also known as “The Ancient One,” the 8,400-year-old male skeleton discovered in Washington state has been the subject of debate for nearly two decades. Argument over his ancestry has gained him notoriety in high-profile newspaper and magazine articles, as well as making him the subject of intense scholarly study.

Officially the jurisdiction of the U.S. Army Corps of Engineers, Kennewick Man was discovered in 1996 and radiocarbon dated to 8500 years ago.

Because of his cranial shape and size he was declared not Native American but instead ‘Caucasoid,’ implying a very different population had once been in the Americas, one that was unrelated to contemporary Native Americans.

But Native Americans long have claimed Kennewick Man as theirs and had asked for repatriation of his remains for burial according to their customs.

Meltzer, collaborating with his geneticist colleague Eske Willerslev and his team at the Centre for GeoGenetics at the University of Copenhagen, in June reported the results of their analysis of the DNA of Kennewick in the prestigious British journal Nature in the scientific paper “The ancestry and affiliations of Kennewick Man.”

The results were announced at a news conference, settling the question based on first-ever DNA evidence: Kennewick Man is Native American.

The announcement garnered national and international media attention, and propelled a new push to return the skeleton to a coalition of Columbia Basin tribes. Sen. Patty Murray (D-WA) introduced the Bring the Ancient One Home Act of 2015 and Washington Gov. Jay Inslee has offered state assistance for returning the remains to Native Tribes.

Science named the Kennewick work one of its nine runners-up in the highly esteemed magazine’s annual “Breakthrough of the Year” competition.

The research article has been viewed more than 60,000 times. It has achieved a ranking of 665, which puts it in the 99th percentile of 169,466 tracked articles of a similar age in all journals, and in the 94th percentile of 958 tracked articles of a similar age in Nature.

In “Kennewick Man: coming to closure,” an article in the December issue of Antiquity, a journal of Cambridge University Press, Meltzer noted that the DNA merely confirmed what the tribes had known all along: “We are him, he is us,” said one tribal spokesman. Meltzer concludes: “We presented the DNA evidence. The tribal members gave it meaning.”

Click here to read more about the research.

Prehistoric vacuum cleaner captures singular award

Paleontologists Louis L. Jacobs, SMU, and Anthony Fiorillo, Perot Museum, have identified a new species of marine mammal from bones recovered from Unalaska, an Aleutian island in the North Pacific. (Hillsman Jackson, SMU)
Paleontologists Louis L. Jacobs, SMU, and Anthony Fiorillo, Perot Museum, have identified a new species of marine mammal from bones recovered from Unalaska, an Aleutian island in the North Pacific. (Hillsman Jackson, SMU)

Science writer Laura Geggel with Live Science named a new species of extinct marine mammal identified by two SMU paleontologists among “The 10 Strangest Animal Discoveries of 2015.”

The new species, dubbed a prehistoric hoover by London’s Daily Mail online news site, was identified by SMU paleontologist Louis L. Jacobs, a professor in the Roy M. Huffington Department of Earth Sciences, Dedman College of Humanities and Sciences, and paleontologist and SMU adjunct research professor Anthony Fiorillo, vice president of research and collections and chief curator at the Perot Museum of Nature and Science.

Jacobs and Fiorillo co-authored a study about the identification of new fossils from the oddball creature Desmostylia, discovered in the same waters where the popular “Deadliest Catch” TV show is filmed. The hippo-like creature ate like a vacuum cleaner and is a new genus and species of the only order of marine mammals ever to go extinct — surviving a mere 23 million years.

Desmostylians, every single species combined, lived in an interval between 33 million and 10 million years ago. Their strange columnar teeth and odd style of eating don’t occur in any other animal, Jacobs said.

SMU campus hosted the world’s premier physicists

The SMU Department of Physics hosted the “23rd International Workshop on Deep Inelastic Scattering and Related Subjects” from April 27-May 1, 2015. Deep Inelastic Scattering is the process of probing the quantum particles that make up our universe.

As noted by the CERN Courier — the news magazine of the CERN Laboratory in Geneva, which hosts the Large Hadron Collider, the world’s largest science experiment — more than 250 scientists from 30 countries presented more than 200 talks on a multitude of subjects relevant to experimental and theoretical research. SMU physicists presented at the conference.

The SMU organizing committee was led by Fred Olness, professor and chair of the SMU Department of Physics in Dedman College, who also gave opening and closing remarks at the conference. The committee consisted of other SMU faculty, including Jodi Cooley, associate professor; Simon Dalley, senior lecturer; Robert Kehoe, professor; Pavel Nadolsky, associate professor, who also presented progress on experiments at CERN’s Large Hadron Collider; Randy Scalise, senior lecturer; and Stephen Sekula, associate professor.

Sekula also organized a series of short talks for the public about physics and the big questions that face us as we try to understand our universe.

Click here to read more about the research.