NEW TWO-SPEAKER FORMAT for 2019-2020!
Costas Arvanitis, Ph.D.
Assistant Professor
George W. Woodruff School of Mechanical Engineering
Georgia Tech
RESEARCH
Costas Arvanitis’ research is focused on biomedical ultrasound and image guided therapy. His work focuses on understanding the biological effects of ultrasound and of acoustically induced microbubble oscillations (acoustic cavitation) and using them to study complex biological systems, such as the neurovascular network and the tumor microenvironment, with the goal of developing novel therapies for the treatment of cancer and central nervous system diseases and disorders.The current research efforts of the lab are focused on the study of the interactions of ultrasound with single and multiple cells and cell types, ultrasound mediated transport of molecules and pharmaceuticals across cellular and vascular barriers, and microbubble dynamics in vessels and tissues.
To facilitate our research, we engineer and integrate multi-modality and multi-scale systems with numerical models and in vivo and in vitro experimentation. We envision that such systems and approaches will allow us to study and understand biological systems in a completely different way, resulting in new concepts, tools and methods to treat cancer and central nervous system diseases and disorders.
BIO
Costas Arvanitis, Ph.D., joined Georgia Institute of Technology as a joint Assistant Professor at the George W. Woodruff School of Mechanical Engineering and the Wallace H. Coulter Department of Biomedical Engineering in August 2016. Before joining Georgia Institute of Technology he was Instructor (Research Faculty) at Harvard Medical Scholl and Brigham and Women’s Hospital. Arvanitis has also worked as a research fellow in the Biomedical Ultrasonics, Biotherapy and Biopharmaceuticals Laboratory at the Institute of Biomedical Engineering at the University of Oxford.
Thomas Orlando, Ph.D.
Professor, School of Chemistry and Biochemistry
Associate Dean for Energy Research, College of Sciences
Adjunct Professor, School of Physics
Georgia Tech
RESEARCH
Professor Orlando directs the Electron- and Photon-Induced Chemistry on Surfaces Lab (EPICS). EPICS is primarily a surface chemistry and physics group that focuses on the use of high-powered pulsed lasers, low-energy electron scattering, micro-plasmas, mass spectrometry, and ultrahigh vacuum surface science techniques. The unifying theme within the group is to understand the important role electronic excitations of surfaces and interfaces play in chemical transformations, which can occur in radiation environments within the interstellar media, plasmas, or planetary magnetospheres. Understanding nonequilibrium processing of surfaces and materials within and beyond our solar system is a specific area of focus, particularly the role of electrons, protons, and extreme ultraviolet radiation in transforming surfaces of planets, their satellites (moons), asteroids, and comets. In addition, there are major efforts to examine the atomic and chemical composition of meteorite and lunar samples that may hold clues to the details of planet formation and possibly the chemical origin of life. These fundamental efforts are connected to many space missions including the Galileo, Cassini, MESSENGER, Deep Impact, and LADEE. Efforts are also underway that examine the chemical processes that occur in star-forming regions, within the solar nebulae, and on grains within interstellar regions. This research group is also affiliated with the Jet Propulsion Laboratory NAI on "Titan as a Pre-biotic Chemical System" and the John Hopkins University Applied Physics Laboratory Lunar Science and SERVI Institutes.
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NEW TWO-SPEAKER FORMAT for 2019-2020!
Blair Brettmann, Ph.D.
Assistant Professor
School of Materials Science and Engineering
Georgia Tech
RESEARCH
Brettmann’s current research interests focus on developing technologies that enable multicomponent, rapidly customizable product design, with a specific focus on polymer systems. Mass customization of manufactured material goods presents significant technical challenges, but could yield significant rewards, similar to advances in “just in time” logistics and on-demand consumer services. Substantial challenges in engineering and design, extending from the complexity of multicomponent functional materials and the difficulty in applying scientific principles to these complex systems, slow material product development. Her research group designs and studies new processing and characterization technologies using both experiments and theory, focusing on linking molecular to micron scale phenomena in complex systems to product performance.
BIO
Blair Brettmann received her B.S. in Chemical Engineering at the University of Texas at Austin in 2007. She received her Master's in Chemical Engineering Practice from MIT in 2009 following internships at GlaxoSmithKline (Upper Merion, PA) and Mawana Sugar Works (Mawana, India). Blair received her Ph.D. in Chemical Engineering at MIT in 2012 working with the Novartis-MIT Center for Continuous Manufacturing under Prof. Bernhardt Trout. Her research focused on solid-state characterization and application of pharmaceutical formulations prepared by electrospinning. Following her Ph.D., Blair worked as a research engineer for Saint-Gobain Ceramics and Plastics for two years. While at Saint-Gobain she worked on polymer-based wet coatings and dispersions for various applications, including window films, glass fiber mats and architectural fabrics. Later, Blair served as a postdoctoral researcher in the Institute for Molecular Engineering at the University of Chicago with Prof. Matthew Tirrell.
Rebecca Levit, M.D.
Clinical Assistant Professor
Wallace H. Coulter Department of Biomedical Engineering
Georgia Tech and Emory University
Assistant Professor
Division of Cardiology
Emory University
RESEARCH
Cardiovascular diseases are the leading causes of death and disability worldwide. We are dedicated to developing new therapies to help cardiac patients by identifying, testing, and moving new therapies towards clinical use. We study stem cell therapies to prevent heart damage and promote repair. We use biomaterials to increase cell retention, increase efficacy, and target activity. Damage to heart muscle one hour after ischemia-reperfusion. Large amounts of neutrophils have already infiltrated the damaged heart muscle. Our lab is working on new therapies to minimize the damaging effects of these cells.
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Timothy A. Springer, Ph.D.
Latham Family Professor
Professor of Biological Chemistry and Molecular Pharmacology, Professor of Medicine
Harvard Medical School
Program in Cellular and Molecular Medicine
Division of Hematology/Oncology
Department of Medicine
Boston Children’s Hospital
Tim received his B.A. in Biochemistry from University of California in 1971, his Ph.D. in Molecular Biology and Biochemistry from Harvard in 1976 and did a fellowship with Cesar Milstein in Cambridge, England. He began as Assistant Professor on the Quad at HMS in 1977 and has been here ever since, although his institution has changed several times. Since 1989 Springer has been Latham Family Professor. He currently is Professor of Biological Chemistry and Molecular Pharmacology and of Medicine at HMS and in the Program of Cellular and Molecular Medicine, and in the Division of Hematology, Department of Medicine at Children’s Hospital.
Springer discovered with monoclonal antibodies, then cloned and functionally and structurally characterized, many of the adhesion receptors in the immune system. He was the first to demonstrate that lymphocytes and leukocytes had adhesion molecules. His work on these receptors has advanced to characterizing their interactions and allosteric transitions by x-ray crystallography, electron microscopy, and laser tweezers force spectroscopy.
He discovered the lymphocyte function-associated (LFA) molecules, the intercellular adhesion molecules (ICAMs), and the first subfamily of integrins. He discovered that LFA-1 bound to ICAM-1, that LFA-2 (CD2) bound to LFA-3, and that blocking either of these adhesion pathways could block antigen recognition by T lymphocytes. These two pathways were the first examples of like-unlike cell adhesive recognition in biology. These discoveries directly led to the development and FDA approval of efalizumab (Raptiva, Genentech) - an antibody to LFA-1, and Alefacept (Amevive, Biogen) - the LFA-3 ectodomain fused to Fc, both for plaque psoriasis.
Springer later discovered the three step paradigm for leukocyte diapedesis: 1) rolling adhesion of leukocytes on the vessel wall through a translating zone of selectin-carbohydrate adhesion; 2) activation of G protein-coupled receptors on the leukocyte by chemoattractants presented by vascular endothelium; and 3) activation of integrin adhesiveness for CAMs on endothelium, which mediates firm adhesion and leukocyte migration through the vessel wall. The use of different molecular digits in each step creates area codes that govern which particular subset of leukocytes or lymphocytes will emigrate from the bloodstream to a particular subset of inflammatory signals. This together with the realization that blocking any of these steps could completely block emigration led Springer to found LeukoSite in 1993. In 1996 LeukoSite published that an antibody to integrin α4β7, a lymphocyte homing receptor for mucosal tissues, rapidly resolved colitis in non-human primates. This antibody, vedolizumab (Entyvio, Takeda) was approved for moderate to severe ulcerative colitis and Crohns disease in 2014. Springer recruited to the SAB Herman Waldmann, the creator of the antibody CAMPATH-1 (Alemtuzumab). Waldmann arranged to license CAMPATH-1 to LeukoSite in 1997, which was approved by the FDA for B cell chronic lymphocytic leukemia in 2001. CAMPATH was later acquired by Genzyme, and reintroduced as Lemtrada, which was approved for multiple sclerosis in 2013. LeukoSite went public in 1998 and acquired ProScript and with it the proteasome inhibitor bortezimib in 1999, which was approved for multiple myeloma in 2003 (Velcade, Millenium Pharmaceuticals). LeukoSite was acquired by Millenium in December 1999 and as 35% of Millenium was valued at $3 billion by 2001.
Springer’s academic interests now focus on how protein conformational change together with tensile force activates integrins, von Willebrand factor, the transforming growth factor-β family, and adhesins on malaria sporozoites, and discovering new binding partners. Springer has over 500 publications, a Hirsch index of 147, and over 30 patents. He is a member of the National Academy of Sciences and his honors include the Crafoord Prize, the American Association of Immunologists Meritorious Career Award, and the Stratton Medal from the American Society of Hematology.
Springer is an investor in Selecta Bioscience since its B round and a founding investor in Moderna Therapeutics and Editas Medicine. He is a Resident Professor at Pfizer. He is founder and investor in Scholar Rock and in Morphic Rock Therapeutics, and board member and lead angel of Ab Initio Biotherapeutics. IRR to date (12/31/08 to 3/31/16) is 78% for the private investments, excluding founders shares. As a philanthropist, Springer has endowed Chairs at Harvard Medical School and Children’s Hospital, and is on the Children’s Hospital Boston Board of Trust.
Current projects include a non-profit to advance entrepreneurship and innovation in protein therapeutics and open-source antibodies and small molecules. Next is a dual-acting malaria vaccine, to both protect humans from being infected, and to prevent mosquitos from transmitting infection.
The Bioengineering Seminar Series is co-hosted by the Parker H. Petit Institute for Bioengineering and Bioscience, and the Wallace H. Coulter Department of Biomedical Engineering at Georgia Tech and Emory University.
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NEW TWO-SPEAKER FORMAT for 2019-2020!
Nicoleta Serban, Ph.D.
Professor
H. Milton Stewart School of Industrial and Systems Engineering
Georgia Tech
RESEARCH
Nicoleta Serban's research interests on Health Analytics span various dimensions including large-scale data representation with a focus on processing patient-level health information into data features dictated by various considerations, such as data-generation process and data sparsity; machine learning and statistical modeling to acquire knowledge from a compilation of health-related datasets with a focus on geographic and temporal variations; and integration of statistical estimates into informed decision making in healthcare delivery and into managing the complexity of the healthcare system.
BIO
Nicoleta Serban's education and research trajectory makes her unique in the pursuit of data-driven discovery endeavors. While trained as a mathematician at the most prestigious university in Romania, she pursued a doctoral degree in Statistics at Carnegie Mellon University. Her doctoral research focused on fundamental statistical methods with application to genomics and protein structure determination. After graduation, she changed fields to take a tenure-track position in an engineering school at Georgia Institute of Technology. While at Georgia Tech, she has been engaged in challenging engineering-focused research spanning multiple fields, including enterprise transformation, degradation modeling and monitoring, and healthcare among others. In 2010, she was granted the NSF CAREER award for research in service equity and access. Her research record is quite diverse, from mathematical statistics to modeling to data analysis to qualitative insights on causality and complexity. To date, she has published more than 25 journal articles, and a collaborative (with Dr. William B. Rouse) book published by MIT Press. The book title is Understanding and Managing the Complexity of Healthcare. She is an Area Editor for physical sciences, engineering, and the environment for Annals of Applied Statistics and she was invited reviewer for more than 75 papers. She has reviewed for multiple funding agency and she has served in various workshops organized by the National Academy of Engineering.
Jeffrey Skolnick, Ph.D.
Professor, Mary and Maisie Gibson Chair
Director, Center for the Study of Systems Biology
Georgia Research Alliance Eminent Schol in Computational Systems Biology
Georgia Tech
RESEARCH
- Systems Biology, Computational Biology, and Bioinformatics
- Cancer Metabolomics
- Prediction of protein tertiary and quaternary structure and folding pathways
- Prediction of membrane protein tertiary structure
- Prediction of DNA-binding proteins
- Protein Evolution
- Prediction of small molecule ligands for drug discovery
- Prediction of druggable protein targets
- Drug Design
- Automatic assignment of enzymes to metabolic pathways
- Simulation of Virtual Cells
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"Very Fast CRISPR On Demand"
Taekjip Ha, Ph.D.
Bloomberg Distingushed Professor
Professor, Biophysics and Biophysical Chemistry
Professor, Biomedical Engineering
Investigator, Howard Hughes Medical Institute
Johns Hopkins University
Taekjip Ha analyzes single molecules to understand how they act in complex biological systems. Ha and his team combine sophisticated biophysical manipulation techniques with fluorescence imaging to visualize and manipulate protein, RNA, and DNA molecules. Probing these molecules allows the researchers to decipher such innate properties as a molecule’s “bendability” and how it binds and interacts with other molecules. Ha’s team strives to emulate or work within natural cellular environments while studying single molecules, testing diverse protein-nucleic acid and protein-protein interactions at unprecedented spatial and temporal resolution.
The Bioengineering Seminar Series is co-hosted by the Parker H. Petit Institute for Bioengineering and Bioscience, and the Wallace H. Coulter Department of Biomedical Engineering at Georgia Tech and Emory University.
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NEW TWO-SPEAKER FORMAT for 2019-2020!
Seth Hutchinson, Ph.D.
Professor and KUKA Chair for Robotics
School of Interactive Computing
Executive Director of the Institute for Robotics and Intelligent Machines
Georgia Tech
RESEARCH
Robots never know exactly where they are, what they see, or what they're doing. They live in dynamic environments, and must coexist with other, sometimes adversarial agents. Robots are nonlinear systems that can be underactuated, redundant, or constrained, giving rise to complicated problems in automatic control. Many of even the most fundamental computational problems in robotics are provably hard.
Over the years, these are the issues that have driven my group's research in robotics. Topics of our research include visual servo control, planning with uncertainty, pursuit-evasion games, as well as mainstream problems from path planning and computer vision. The links to the left will take you to pages that describe some of our results to date.
Gregory S. Sawicki, Ph.D.
Associate Professor
George W. Woodruff School of Mechanical Engineering and
School of Biological Sciences
Georgia Tech
"A Bio-inspired Approach to Lower-limb Exoskeleton Design for Augmenting Human Locomotion"
RESEARCH
Gregory Sawicki, Ph.D., directs the Human Physiology of Wearable Robotics (PoWeR) laboratory—where the goal is to combine tools from engineering, physiology and neuroscience to discover neuromechanical principles underpinning optimal locomotion performance and apply them to develop lower-limb robotic devices capable of improving both healthy and impaired human locomotion (e.g., for elite athletes, aging baby-boomers, post-stroke community ambulators).
By focusing on the human side of the human-machine interface, Sawicki and his group have begun to create a roadmap for the design of lower-limb robotic exoskeletons that are truly symbiotic---that is, wearable devices that work seamlessly in concert with the underlying physiological systems to facilitate the emergence of augmented human locomotion performance.
BACKGROUND
Sawicki is an Associate Professor at Georgia Tech with appointments in the School of Mechanical Engineering and the School of Biological Sciences. He holds a B.S. from Cornell University (’99) and a M.S. in Mechanical Engineering from University of California-Davis (’01).
Sawicki completed his Ph.D. in Human Neuromechanics at the University of Michigan, Ann-Arbor (‘07) and was an NIH-funded Post-Doctoral Fellow in Integrative Biology at Brown University (‘07-‘09). Sawicki was a faculty member in the Joint Department of Biomedical Engineering at NC State and UNC Chapel Hill from 2009-2017. In summer of 2017, he joined the faculty at Georgia Tech with appointments in Mechanical Engineering 3/4 and Biological Sciences 1/4.
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Lydia Bourouiba, Ph.D.
Associate Professor, Civil and Environmental Engineering and Mechanical Engineering
Affiliate Faculty of the Institute for Medical Engineering and Science
Harvard-MIT Health Sciences and Technology (HST) Faculty
Affiliate Faculty of Harvard Medical School
Physical applied mathematician focusing on problems at the interface of fluid dynamics and disease transmission with the aim of elucidating the fundamental physical mechanisms shaping the epidemiology and disease transmission dynamics in human, animal and plant populations.
With a doctoral research focused on the theoretical and numerical study of rotating homogeneous turbulence and a subsequent postdoctoral research focused on the mathematical modeling of infectious diseases and epidemiology, the focus of the Bourouiba Group is to elucidate the poorly understood mechanisms of disease transmission through the lens of fluid dynamics.
The Bioengineering Seminar Series is co-hosted by the Parker H. Petit Institute for Bioengineering and Bioscience, and the Wallace H. Coulter Department of Biomedical Engineering at Georgia Tech and Emory University.
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Editor's Note: This essay by Kimberly Chen and Matthew Herron was originally published in The Science Breaker on Sept. 10, 2019. It is reposted here with permission.
Discussions about the evolution of multicellularity tend to focus on animals and plants, but there have actually been at least 25 independent origins of multicellularity in the history of life on this planet, including fungi, slime molds, several groups of algae, cyanobacteria and myxobacteria. So how did early single cells evolve into organisms consisting of multiple cells, and why? What were the advantages of being a multicellular organism?
It would be helpful in answering these critical questions if we could study the fossil history of multicellular organisms. However, few fossils have been found that show the earliest stages of the transition to multicellular life. Most such transitions happened hundreds of millions or even billions of years ago, and fossils that old are very rare. So it is really hard to know just what happened that far back.
Since we couldn't learn much from fossils, we used experimental evolution to replay life's tape in the laboratory. One favored driver for the evolution of multicellularity is Predation. Because most predators can only consume prey up to a certain size, getting bigger can provide protection against being eaten, and one way for single-celled organisms to get bigger is to form multicellular structures.
We used single-celled, free-swimming green algae (Chlamydomonas reinhardtii) to explore the possible evolution of multicellularity. The predators we used in our experiment are filter-feeding ciliates (Paramecium tetraurelia). Despite being unicellular, these ciliates are larger and graze on small algae by sweeping them into their mouths with hairlike structures called cilia. We cultured some algae with predators and some without predators for a year to see if predators would increase the evolution of multicellularity.
Single-celled algae normally multiply by a process called multiple fission, where a cell goes through one to three divisions to produce two, four or eight daughter cells. These daughters then hatch out of the mother cell wall to start the cycle again. By the end of our experiment, some of the cultures grown with predators had become multicellular by modifying their cell life cycle. In these evolved multicellular algae, we did not observe the last hatching step when the cell cycle is about to complete.
Instead, we found that each daughter cell continued its cell cycle within the mother cell wall, leading to multicellular clusters. Strictly speaking, cells in each cluster are descendants of a mother cell, and are genetic clones of each other. As clusters continue to grow bigger, they reach a limit and start to release single cells or small clusters of cells. In a separate experiment, we further showed that it is the cluster formation rather than other prey defenses that protects cells from predation. Selective pressure through predators, therefore, can favor the increase of clusters over single cells.
The multicellular life cycle is genetically fixed in the evolved multicellular algae, continuing even when they are grown in normal growth conditions without predators. But there is a price to pay. In nature, single-celled algae use slim threadlike structures called flagella to swim towards the light they need for photosynthesis. However, in the evolved multicellular algae each cell's flagella, even though they are present and active, are trapped within the mother cell wall. As a result, the multicellular clusters do not show noticeable movement. Such a drawback can be mitigated in the laboratory, since we culture these algae in an incubator with an ample supply of light. They might not be so lucky in nature.
From this experiment, we learned that multicellularity evolves readily in response to predation. This initial transition, although being a key step towards more complex life, does not seem to require organisms like green algae to evolve something new. Rather, this can be accomplished through a small modification to the existing cell cycle. The multicellular algae that evolved in our experiment also provide opportunities for further evolution experiments. For example, will they be able to regain the ability to swim? Can they evolve a division of labor, with cells becoming specialized to perform different tasks as we see in more complex multicellular organisms? These questions are under our current investigations.
Kimberly Chen is a postdoctoral researcher and Matthew Herron is a senior research scientist in the School of Biological Sciences.
Editors Note: This story is an abridged version of an article by Kelsey Abernathy and Selena Perrin published originally on Aug. 29, 2019, by the Scheller College of Business. A different headline was set for the College of Sciences audience.
How do you stop millions of pounds of heat-trapping CO2 from ever being emitted? In Georgia Tech’s Summer 2019 Carbon Reduction Challenge, student interns used their ingenuity to identify opportunities for scalable carbon reduction projects at a wide variety of partnering organizations. In doing so, they delivered large energy and cost savings to their employers.
Over the 10-week challenge, the students benefited from frequent coaching sessions led by faculty co-directors Kim Cobb, Director of the Global Change Program and professor in the School of Earth and Atmospheric Sciences, and Beril Toktay, Director of the Ray C. Anderson Center for Sustainable Business and professor in the Scheller College of Business.
Now in its third year, the internship-based Challenge has resulted in a total of over 30 million pounds of avoided CO2 emissions while delivering hundreds of thousands of dollars in avoided energy costs to partner organizations. In this year’s Challenge, 45 students from Georgia Tech, Agnes Scott College, Clemson University, Emory University, Georgia State University, and the University of Georgia competed for prizes provided by the Sheth Foundation.
On August 13, students presented their Summer 2019 projects to the general public and key industry leaders at the Challenge’s Summer Poster Expo at the Georgia Tech Scheller College of Business. Partnering organizations included Agnes Scott College, AT&T, Boeing, Emory University, Hartsfield-Jackson Atlanta International Airport, Jacobs Engineering, Michaud Cooley Erickson, and SunTrust Banks.
The top prize of $5,000 was awarded to Georgia Tech College of Sciences students Rebecca Guth-Metzler, Brooke Mancinelli-Rothschild, and Priyam Raut, who worked to implement a number of energy-saving initiatives in the Petit Institute for Bioengineering and Bioscience Building. Working with Georgia Tech Facilities, they replaced fluorescent light bulbs with LED bulbs and created a system for bundling energy-intensive autoclave loads. When fully implemented, their proposed changes will result in over 250,000 pounds of CO2 reductions per year.
“Our scientific research requires that we work in labs that are energy-intensive,” the team said. “We saw the Carbon Reduction Challenge as an opportunity to advocate for updates to our lab building and to lead the way toward more environmentally friendly lab practices.”
The second prize went to a team that developed a proactive plan to recycle aluminum in SunTrust signage that will need to be replaced as the company rebrands following its merger with BB&T. This project will save 1.2 million pounds of CO2 and generate a revenue of $125,000.
Two projects tied for third place. One is a project to upgrade dozens of outdoor lighting fixtures to LEDs at Michaud Cooley Erickson in Minneapolis, Minnesota, which will save 62,000 pounds of CO2 and $5,500 per year. The other project was a proposal for a more efficient lighting schedule for sprawling buildings at the Boeing campus in Seattle, Washington, which will translate to a savings of 6 million pounds of CO2 and $700,000 per year. Honorable mentions were awarded to projects with Agnes Scott College, Jacobs Engineering, and SunTrust Banks.
Student interns’ innovative work at the Poster Expo illustrated that employees do not need to have “sustainability” in their job title in order to be successful climate champions at work. “The Carbon Reduction Challenge is a particularly innovative real-world learning opportunity,” said Andrea Pinabell, President of Southface Institute, who served as a judge. “It equips students for success in an era of increasing interest in sustainable and climate-driven solutions.”
Top Three Teams
First Place ($5000)
Georgia Tech Labs Project
Rebecca Guth-Metzler (Biochemistry, second-year PhD student)
Brooke Mancinelli-Rothschiled (Biochemistry, second-year PhD student)
Priyam Raut (Bioinformatics, MS ’20)
Second Place ($3000)
SunTrust Banks Project
Nicholas Loprinzo (Industrial and Systems Engineering, BS ’20)
Raina Parikh (double major: Business Administration, International Affairs and Modern Languages; BS ’21)
Sarah Poersch (Business Administration, BS ’19)
Hongyangyang Shi (Analytics, MS ’19)
Athara Vaidya (Georgia State University, Analytics, MS ’19)
Third Place (tie, $1000 each)
Boeing Project
Kian Halim (Earth and Atmospheric Sciences, BS ’21)
Louis Hou (Business Administration, BS ’20)
Sam Shapiro (Computer Science, BS ’20)
Chris Wink (Business Administration, BS ’20)
Michaud Cooley Erickson Project
Nic Fite (Electrical Engineering, BS ’22)
If your ancestry in the United States stretches back more than 250 years, you may have Native American forbears. A new population genetics study shows that Americans with early European or early African ancestry can also have Native American gene groups.
Those Americans usually have family roots near the traditional homes of the respective tribes found in their genes, according to research led by the Georgia Institute of Technology. But where the descendants are today differs between these groups.
“People of Western European heritage have Native gene sequences from tribes that were located near where they now live,” said Andrew Conley, who led the study and is a research scientist in Georgia Tech’s School of Biological Sciences. “For African descendants, Native American ancestry looks like it came from regional groups of Native Americans in the southeastern United States.”
Many Americans descending from enslaved Africans later left the South in the Great Northward Migration, took those Native American sequences with them, and apparently no longer significantly reproduced with indigenous populations.
Americans with European heritage going back to Spain, mostly people who immigrated to the U.S. from Mexico, carry sequences from Native American ancestors who were traditionally located in what is Mexico today. This group also carries the most Native American genetic sequences by far, roughly 40% of their total genome, according to the study.
The researchers came to their conclusions by tracking haplotypes, patterns of genetic variants that are passed on by one parent, and that are typical for certain regions and peoples. They published their results in the journal PLoS Genetics on September 23, 2019.
“Haplotype combinations are very different between European, African and Native American ancestries and specific to locations,” Conley said.
The data was extracted from a much larger study, The Health and Retirement Study, sponsored by the National Institute on Aging (NIA) and conducted by the University of Michigan. That study also followed health and finance over time but included genomes and geography. Neither the NIA nor Michigan was part of the Georgia Tech study.
Americans of early African heritage have about 1.0% and of Western European heritage about 0.1% Native American haplotypes, though the difference in those numbers can be deceiving. The native ancestry probably lies a similar number of generations back for both groups.
“With African Americans, it correlates to about eight to nine generations back and probably ends there,” Conley said. “With Western European ancestors, we think about eight to 10 generations ago, and the contact with Native Americans could have also been more continuous.”
Further immigration from Europe likely dropped the percentage of Native American ancestry for the overall sample of Americans with Western European heritage.
“Particularly in the Mid-Atlantic and the Northeast there is almost no Native American ancestry among European descendants,” Conley said. “When you go out West, that’s where you have the most Native American ancestry in European populations.”
There was also an outlier group with European heritage from Spain.
“In parts of the Southwest, there are people of Spanish descent with also distinctive Native American ancestry. These groups call themselves Hispanos or Nuevomexicanos,” Conley said. “Their native American ancestry does not come from present-day Mexico. There were Spanish settlers in the region 400 years ago, and they could be the European ancestors of the Nuevomexicanos.”
The following coauthors from Georgia Tech collaborated on the study: King Jordan and Lavanya Rishishwar. Any findings, conclusions, or recommendations are those of the study’s authors.
Writer & Media Representative: Ben Brumfield (404-660-1408), email: ben.brumfield@comm.gatech.edu
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