Their work, drawing global attention, is newly published in the journal Insects.
The researchers examined 13 individual male fossilized ants that lived during the Miocene epoch and identified them as a new genus of primordial ants. The team used the X-ray light source PETRA III at the German Electron Synchrotron (DESY) in Hamburg, aided by state-of-the-art imaging technology. The name given to the new species and genus: "†Desyopone hereon gen. et sp. nov," to honor the two research institutions involved--DESY and Hereon.
The males resemble species of the relictual lineage Aneuretinae, "but which effectively belong to the Ponerinae, as revealed by advanced 3D-imaging technology (synchrotron radiation micro-computed tomography, SR-µ-CT)," the authors wrote. "We subsequently propose a revision of ant classification at the subfamily level. We also recognize that the new species belongs to a new genus based on recent phylogenomic results that have clarified the generic boundaries of Ponerini ants. Our work, therefore, represents an example of reciprocal illumination between phenomic and genomic data."
"The study was really pleasing from a scientific perspective, as we were able to pass through the whole cycle of hypothesis induction based on the original light microscopy, then deductive prediction for structures we then tested using synchrotron radiation, which allowed us to reject the initial hypothesis—and to go even further!" said Boudinot, an Alexander von Humboldt Research Fellow at the Institute of Zoology and Evolutionary Research at Friedrich Schiller University Jena.
"There are a couple of important elements to the study," Boudinot said. "Based on this discovery, we had to redefine two ant subfamilies and two tribes, and we demonstrate the value of the oft-neglected male ants for understanding evolution through the comparison of mandibles of male and females across the phylogeny, revealing a major trend in mandible evolution. In the bigger picture, what I think is significant is that this work marks a boundary for ant paleontology, where we will increasingly be able to use x-ray micro-computed tomography (µ-CT) to generate 3D models for study and quantitative analysis. Soon, we will be able to analyze these phenomic data simultaneously with genomic data. The study of ant morphology and paleontology is transforming and becoming 'big data'! There will be lots more work to come."
The team, in addition to researchers from Friedrich Schiller University Jena, included scientists from the University of Rennes in France, the University of Gdansk in Poland, and the Helmholtz-Zentrum Hereon in Geesthacht, Germany.
In a University of Jena news release, Vincent Perrichot from the University of Rennes explained: "The piece with these ants is from the only amber deposit in Africa so far that has featured fossil organisms in inclusions. Altogether, there are only a few fossil insects from this continent. Although amber has long been used as jewelry by locals in the region, its scientific significance has only become clear to researchers in the last 10 years or so. The specimen therefore offers what is currently a unique insight into an ancient forest ecosystem in Africa.” Its complicated dating was possible only indirectly, by determining the age of the fossil palynomorphs--the spores and pollen--enclosed in the amber, he added.
"Research results such as these are only possible through the use of state-of-the-art technology," according to the University of Jena news release. "As the genetic material of fossils cannot be analyzed, precise data and observations on the morphology of animals are particularly important. Comprehensive data can be obtained using high-resolution imaging techniques, such as micro-computed tomography (CT), in which X-rays are used to look through all layers of the sample."
A quote from Jörg Hammel from the Helmholtz-Zentrum Hereon: “Since the ants enclosed in amber that are to be examined are very small and only show a very weak contrast in classical CT, we carried out the CT at our measuring station, which specializes in such micro-tomography. This provided the researchers with a stack of images that basically showed the sample that was being studied slice by slice.”
"Put together, these produced detailed three-dimensional images of the internal structure of the animals, which the researchers could use to reconstruct the anatomy with precision," the news release related. "This was the only way to exactly identify the details that ultimately led to the new species and genus being determined."
Boudinot, a two-year Alexander von Humboldt Research Fellow, recently was awarded a Peter S. Buck Research Fellowship at the Smithsonian Institution, Washington, D.C., and will begin his fellowship there early next year.
Boudinot received his doctorate in entomology from UC Davis in 2020, working with major professor Phil Ward. During his years at UC Davis, Boudinot received the John Henry Comstock Award from the Pacific Branch, Entomological Society of America, the highest ESA graduate student honor.
The research appears in the February edition of the Zoological Journal of the Linnean Society.
The fossil, from the Cretaceous geological period and now part of the American Museum of Natural History collection, “was an extremely cool find,” said Boudinot, who is researching evolutionary and comparative anatomy in Jena under a two-year Alexander von Humboldt Research Fellowship. He received his UC Davis doctorate in entomology in 2020.
Boudinot, the lead researcher and corresponding author of the paper, describes the fossil as a “relatively large piece of Kachin amber containing three wingless adult female ants plus a wingless pupa.”
“The key points are that there is a remarkable diversity of evolutionarily intermediate or ‘missing link' ants in the Cretaceous fossil record, and folks have basically assumed that they were eusocial because wingless females—presumptive workers—had been found,” Boudinot said. “The fossil we discovered cuts through the uncertainty because of the pupa; this is the first ever pupa found from Mesozoic fossils, and we confirmed through the use of cutting-edge technology (µ-CT) that it is from the same species as one of the adults. Because pupae are immobile, it is reasonable that she was dropped during transportation by the adult wingless female.”
“Importantly, the transport of larvae and pupae--termed “brood transport”--is a unique feature of ants among all Hymenoptera, and is a critical social behavior,“ Boudinot said. “This fossil is the first evidence of nursing by wingless females, very strongly indicating that advanced social organization had evolved before the origin of the modern ants in the Early Cretaceous.”
“Taken altogether, this fossil opens a totally new pathway for the study of arthropod evolution: Paleoanatomy and paleosociobiology. There is far more to learn from fossils than previously realized!”
The focal amber piece originated from a deposit in theHukawng Valley,Kachin State, northern Myanmar, dated near the Albian–Cenomanian boundary.
Co-authors are Adrian Richter and Rolf Georg Beutel, Friedrich Schiller University Jena; Julian Katzke, Roberto Keller and Evan Economo, Okinawa Institute of Science and Technology Graduate University, Japan; Júlio C M Chaul, Federal University of Viçosa, Brazil; and Shûhei Yamamoto of Hokkaido University Museum, Hokkaido University.
Yamamoto discovered the fossil, Richter and Katzke generated and rendered the µ-CT data, and Beutel, Chaul and Economo were integral for shaping the conclusions, Boudinot said. “The study also represents a breakthrough in the application of µ-CT technology for taxonomy, as we were able to make very precise comparisons among the fossilized individuals, allowing me to revise the classification of the genus †Gerontoformica.”
Globally, there are more than 14,000 described species of ants, Boudinot says "As a community, we usually throw around the figure 20,000 as our rough total estimate for three reasons: (1) there is an incredible diversity of ants in tropical ecosystems that have yet to be formally named, (2) modern sequencing technology is allowing us to gain deep insights into the population structure and relationships of living species, thus revealing considerable hidden species-level diversity, and (3) there are over a thousand subspecies names in the ant literature which need to be re-evaluated as these could actually represent proper species. There is a ton of work to do, and Phil Ward and folk are making tremendous progress!"
Regarding extinct species, Boudinot says here are "almost as many fossil ants described as non-avian dinosaurs! As of today, the number stands at about 746 fossil species; of these, only about 50 are described from Mesozoic fossil deposits. This small fraction is critical, however, as they are the key to understanding the patterns of early evolution in the ants!"
The ant world on Twitter is crawling with congratulatory comments and how "awesome" the work is. Wrote one: "Congratulations! Lasius is a familiar genus in Japan, so I will let the Japanese entomologists know about it."
The story behind the story? It all began in the Ward lab. "The Three Ant Men" are now scattered from Idaho to Arizona to Germany.
- Borowiec, who received his doctorate at UC Davis in 2016, is an assistant professor at the University of Idaho.
- Prebus, who received his doctorate at UC Davis in 2018, is a postdoctoral scholar at Arizona State University.
- Boudinot, who received his doctorate at UC Davis in 2020, is in Jena, Germany on a two-year Alexander von Humboldt Research Fellowship to research evolutionary and comparative anatomy.
"Within the Formicidae, the higher classification of nearly all subfamilies has been recently revised given the findings of molecular phylogenetics," the co-authors wrote in their abstract. "Here, we integrate morphology and molecular data to holistically address the evolution, classification, and identification of the ant genus Lasius, its tribe Lasiini, and their subfamily Formicinae. We find that the crown Lasiini originated around the end of the Cretaceous on the Eurasian continent and is divisible into four morphologically distinct clades: Cladomyrma, the Lasius genus group, the Prenolepis genus group, and a previously undetected lineage we name Metalasius gen.nov., with one extant species M. myrmidon comb. nov. and one fossil species, †M. pumilus comb. nov. " (See more.)
Looking back, Prebus and Borowiec said that they were both interested in Lasius atopus "due to its strange morphology and lack of phylogenetic data despite the amount of attention paid to the genus, and planned a collecting trip to the type locality in Mendocino County in 2013."
The collecting trip to Mendocino proved unsuccessful. "But because of Phil's extensive collections. we knew of a population of a closely related species in Gates Canyon near the city of Vacaville," Prebus said. This time the trio collected specimens from several colonies at Gates Canyon, which is located off Pleasants Valley Road.
"For all of us, this was a collaborative side project, so after the study was presented, submitted, and rejected, it took the back-burner while people finished their dissertations, got jobs, got married, had kids, and so on," Prebus recalled. "Speaking personally, the pandemic put quite a few of my postdoc projects on hold after the Arizona State University campus closed, but the small upside amongst the inundation of downsides was that I was able to focus on getting some long-haul projects into shape for publication, including the Lasius study. This involved a huge amount of reanalysis of data that we had already collected, but thankfully didn't require generating any new data."
"In my opinion, one of the really cool aspects of this study is the method of evaluating the placement of fossil taxa in the phylogeny of the subfamily Formicinae," Prebus shared. "Because DNA data aren't available for fossil taxa, the assignment of fossils to ranks higher than species relies on the interpretation of their morphology, and historically that interpretation has relied heavily on expert opinion--and all of the biases that said experts hold. By collecting morphological data from all extant and fossil taxa in our dataset, we were able to unite the DNA data--from extant taxa--and the morphological data--from extant and fossil species--and formalize fossil placement, and evaluate the uncertainty of those placements, in model-based analyses. I think that this study joins a growing trend in systematics in general, in which we are increasingly moving away from expert opinion toward approaches that are testable and repeatable."
Follow the myrmecologists on Twitter:
Wilson, recognized as one of the world's most influential scientists, was known as “The Ant Man,” "The Father of Sociobiology," "The Father of Diversity" and “The Modern-Day Darwin," for his pioneering and trailblazing work that drew global admiration and won scores of scientific awards.
But among his peers, colleagues and mentees, he was known as "Ed."
Wilson's work, On Human Nature, won the Pulitzer Prize in 1979. He won a second Pulitzer in 1991 with The Ants, co-authored with colleague Bert Hölldobler. In 1990, the Royal Swedish Academy of Sciences awarded Wilson the Crafoord Prize in biosciences, the highest scientific award in the field. In 1996, Time magazine named him one of America's 25 most influential people. In 1977 President Jimmy Carter awarded him the National Medal of Science for his contributions toward the advancement of knowledge in biology.
Wilson, according to reports, always considered himself an Alabaman who went to Harvard, rather than a Harvard professor born in Alabama. Born June 10, 1929 in Birmingham, Ed graduated from the University of Alabama in 1949 with two degrees in biology, and received his doctorate in biology from Harvard in 1955. He joined the Harvard faculty in 1956. Although officially retiring in 1996, he remained active as an emeritus professor and honorary curator until his death.
Some tributes from UC Davis faculty and students:
“E. O. Wilson was a towering figure in the study of social insects, in evolutionary biology, and in conservation biology,” said fellow ant specialist and professor Phil Ward of the UC Davis Department of Entomology and Nematology who organized the 2007 E.O. Wilson Festschrift (a collection of writings published in honor of a scholar). “He made important contributions in all of these areas, but his specialty was the study of ants, those ‘little creatures that run the world.' Wilson's book, The Insect Societies (1971), introduced its readers to the fascinating world of ants and other social insects, using language that was both engaging and accessible, yet highly informative.”
“This was followed two decades later by the equally magisterial The Ants, co-authored with Bert Hölldobler,” Ward noted. “These landmark contributions inspired many budding biologists, myself included, to devote ourselves to the study of ants and other social organisms. Equally important, Wilson argued passionately and compellingly for the conservation of biological diversity in a dwindling natural world. He once said that 'destroying rainforest for economic gain is like burning a Renaissance painting to cook a meal.' Let us honor his legacy by heeding this message!”
UC Davis doctoral alumnus Brendon Boudinot of the Phil Ward lab and now a postdoctoral researcher in Germany at the Institute of Zoology and Evolutionary Research, Friedrich Schiller University Jena, says the ant world is reeling with Wilson's passing. “A big chunk of my dissertation was dedicated to testing his hypotheses for the origin and early evolution of ants!”
Boudinot met Wilson when he was visiting the Ant Room at the Harvard Museum of Comparative Zoology in 2013. “The work I was doing was the foundation for my studies on ant males, and I was near the end of the trip, at one of the many microscopes by the window facing the yard,” he said. “Ed surprised me by coming right up to my shoulder at the scope; he asked me what I was working on. I am a bit abashed to say that I couldn't say anything because my mind went blank! Stef Cover, the pins-and-points curator told Ed what I was doing, and for the life of me I will always remember what Wilson said. He was happy that I chose to work on male ants, when this sex has been actively ignored by researchers over the past centuries, and that he himself was more apt to squash one at a light trap than to collect one. I hope that my keys and diagnoses have helped people appreciate male ants.”
“I am so thankful that I met him,” Boudinot said, “and that I was able to work with so many people in his sphere. The ant world is reeling, as he was a gentle giant of myrmecology, and of course biology writ large.”
Doctoral candidate Jill Oberski of the Phil Ward lab met “The Ant Man” in 2019. “I got to meet E. O. Wilson when I traveled to the Harvard Museum of Comparative Zoology in 2019. In addition to myself, there were several other researchers visiting the “Ant Room,” which houses a huge number of type specimens.”
“He asked me about my research on Dorymyrmex taxonomy and biogeography, although as a second-year PhD student I didn't have much to report yet. He was genuinely interested in my work and excited that I was working to resolve Dorymyrmex--which has always been a taxonomic headache. He also told me he recalled watching ants forming cone-shaped nests as a child in Alabama, which could only have been Dorymyrmex. He was exceedingly kind and encouraging.
“Finally, the Ant Room staff and visitors ate lunch together in Ed's office—lobster sandwiches, diet Dr. Pepper, and coffee, as is customary.”
Lynn Kimsey, director of the Bohart Museum of Entomology and a UC Davis distinguished professor of entomology, remembers working near his office when she served as a visiting professor/lecturer (1987 to 1989) at Harvard's Museum of Comparative Zoology, before joining the UC Davis faculty in 1989.
“His office was just down the hall from mine when I taught at Harvard. Here he was, one of the most famous biologists of his generation and I would see him sit down on the sidewalk to show a little kid the ants there. Also, saw him in the sitting on a bench Burlington Mall while his wife shopped, writing on a yellow pad of paper. Totally focused on what he was writing with shopping pandemonium all around. He was brilliant, humble and engaging.”
UC Davis doctoral alumnus Fran Keller, a professor at Folsom Lake College, and a research scientist at the Bohart Museum of Entomology, helped honor his work at a special symposium hosted at the 2005 Entomological Society of America meeting in Fort Lauderdale, Fla.
"Our department of entomology helped fund my trip to Harvard,” she recalled, “and he agreed to meet me over the course of two days in May 2005. The ESA symposium took place in mid-December. I recorded our interview on a cassette tape,” she said, adding she hopes to publish it in a journal.
Wilson responded: “Everyone has an animal that reaches them or that they connect with at some level, even though you were born an entomologist, perhaps yours is the rhino.”
“After my interview with Ed, I bought the book in the MCZ, The Rarest of the Rare: Stories Behind the Treasues at the Harvard Museum of Natural History. In that book, it highlights the extinct and rare species held in the MCZ collections. One of those specimens is the last Xerces butterfly, which was caught by Harry Lange (UC Davis emeritus professor of entomology). Harry's quote in that book, ‘I didn't know it was the last one, I thought there would be more' and then my time eating lunch and then wandering the MCZ collection and chatting with Ed inspired me to create the Xerces t-shirt for the Bohart Museum of Entomology.”
One of Keller's mentors, Tom Schoener, studied with Wilson. “I worked on plant ecology and island biogeography for my undergrad research (Sacramento City College)," she said, "and continued that for awhile in grad school (UC Davis). Ed Wilson was one of the founders of island biogeography.”
As a undergraduate at Sacramento City College, Keller was part of a field trip to hear Wilson speak at his 2002 book tour on The Future of Life.
UC Davis doctoral alumnus Alex Wild, an evolutionary biologist, science photographer and curator of entomology at the University of Texas, Austin, wrote this on his Twitter account, @Myrmecos, which has more than 30,000 followers: “Ed Wilson was one of my science heroes. Over the years I came to admire two things in particular. One was his ability to craft technical books so compelling as to launch scores of scientific careers in their wake.”
“The other thing is how Ed Wilson handled professional disagreement," Wild tweeted. "And he had a lot of those, because Wilson was frequently wrong. About a great range of topics. For a guy known for ant research, his interpretation of ant origins was just… silly.”
"But he continued to support, both financially and professionally, the young upstarts who, over and over, proved him wrong. That's a rare trait for a field as ego-driven as evolutionary biology.”
When a follower asked: “Can you explain to a non-biologist bug enthusiast why his interpretation of ant origins was silly?”, Wild replied: “His arrangement of the ant subfamilies, based on subjective hunches of evolutionary relationships rather than data, bore no resemblance at all to the well-supported relationships from subsequent data-based studies, like https://www.pnas.org/content/103/48/18172. (This 2006 research article, "Evaluating Alternative Hypotheses for the Early Evolution and Diversification of Ants," is co-authored by Seán G. Brady, Ted R. Schultz, Brian L. Fisher, and Philip S. Ward and edited by Bert Hölldobler, University of Würzburg, Würzburg, Germany)
“There are no words that adequately describe E.O. Wilson's courage in challenging dogma, his energy in documenting and sharing the wonders of our planet, or his extraordinary creativity," said Diane Ullman, UC Davis professor of entomology and former chair of the Department of Entomology. "So much of his writing touched me deeply, from his writing about the continuum between art and science (Consilience), to his collaboration with Bert Hölldobler, addressing the incredible biology and behavior of social insects (Superorganism). He wrote a wonderful, 'coming of age' novel, seemingly much inspired by his own youth (Anthill)."
"The first time I was able to hear him speak in person was in 1996 at the International Congress of Entomology in Florence, Italy, where he was the plenary speaker opening the meeting. He spoke passionately about loss of biodiversity, and was sounding the alarm on impact of humans and climate change on the planet. He continued to lead this charge up to the very end, never giving up on proposing potential solutions on a global scale. He was witty and with use of metaphor made us see so very many things."
Caleb Johnson, who teaches writing at Appalachian State University, Boone, N.C., described E.O. Wilson as “the world's forestmost authority on biodiversity” in an April 21, 2020 article in The Bitter Southerner. He referred to him as “A world-renowned scientific thinker whose vision for stopping this unprecedented environmental hemorrhaging is based on more than seven decades of careful witness, writing, and work in ecology and conservation."
Johnson wrote that Wilson lost his right eye in a fishing accident in the summer of 1936 near Paradise Beach, Fla., but he never let that stop his goals.
"In the 1940s, E.O. Wilson was an Alabama teenager who wandered the bottomland around Mobile and studied its creatures. He never stopped and became the world's foremost authority on biodiversity. He's 90 now, but still working, because he knows there's a way to undo the damage we've done to Mother Earth."
Boudinot, who studied with major professor Phil Ward of the UC Davis Department of Entomology and Nematology, is the second UC Davis-affiliated entomologist to receive the honor in its 28-year history. Jessica Gillung of the Lynn Kimsey lab, Bohart Museum of Entomology, won the award in 2019.
Snodgrass (1875-1962), a leader in insect morphology, is known for his 76 scientific articles and six books, including Insects, Their Ways and Means of Living (1930) and the book considered to be his crowning achievement, the Principles of Insect Morphology (1935).
Boudinot has them all. “Principles of Insect Morphology and the Anatomy of the Honey Bee were the foundation of my studies,” he said. “I have both, plus his Textbook of Arthropod Morphology and Insects, Their Ways and Means of Living on my desk in the lab.”
The Snodgrass Award, which includes a certificate and cash prize, recognizes outstanding research by a PhD student who has completed a research thesis or dissertation in arthropod morphology, systematics, taxonomy, or evolution. Nominees are scored on honors, awards, achievements and recognition; recommendations of professors and advisors; grantsmanship, publications, creativity and innovation of thesis or dissertation; and contribution to morphology.
Boudinot's dissertation: “Systematic and Evolutionary Morphology: Case Studies on Formicidae, Mesozoic Aculeata, and Hexapodan Genitalia.”
He earlier received the prestigious Alexander von Humboldt Research Fellowship to do research on evolutionary and comparative anatomy in Jena, Germany. He will locate to Germany in early 2021 for the two-year fellowship, after completing intensive language studies.
'I Am a Morphologist Because of Robert Evans Snodgrass'
“I am a morphologist because of Robert Evans Snodgrass,” Boudinot wrote in his application. “Although I have had pressure from my earliest undergraduate to become a molecular systematist, it was my chance encounter with Snodgrass's Principles of Insect Morphology late one night in the college library that set the course of my career. I had struggled for years at that point to understand the biodiversity of insects and to untangle the deep morass of arcane terminology, but my vision was illuminated by the conceptual clarity, linguistic simplicity, and exceptional engravings of the Principles. This work continues to hold special dominion over my thinking, as it is through the principle of mechanical function for explaining comparative anatomical observations that I have come to my present understanding of systematic and evolutionary morphology.”
Boudinot wrote that his “career objective, in brief, is to resolve the morphological evolution of insects through the synthesis traditional morphology, as represented by Snodgrass, with recent trends in digital anatomy and bioinformatics. I envision a future wherein students rely not on Borror & Delong, a holdover from Comstock's 19thCentury manual, but rather learn about insect structure, function, classification, and evolution through manipulation of three- and four-dimensional digital anatomical models, substantiated via manual curation and dissection. I want students to see for themselves what I have understood through the study of Snodgrass's work, balanced by contemporary research: The origin of the Arthropoda and morphological transformation through geological time to the resplendent, and endangered, diversity of today.
“In sum, my identity as an entomologist, and as a scientist more broadly, is due to the insights on the language and phenomenology of morphological evolution I gained from the oeuvre of Snodgrass. Without these works, I would probably still be a botanist.”
Boudinot's research interests include the origin and evolution of complex phenotypic systems from the perspective of phylogenetic systematics, including molecular and paleontological evidence. Specializing on morphological identity and evolutionary transformation, the skeletomuscular system of Arthropoda, with emphasis on the male genitalia of Hexapoda and systematics of the Hymenoptera, particularly the Formicidae.
John Henry Comstock Award
Highly honored for his academics, leadership, public service activities, professional activities and publications while at UC Davis, Boudinot received the 2019 John Henry Comstock Award, the top graduate student award given by ESA's Pacific Branch. The branch encompasses 11 Western states, U.S. territories, and parts of Canada and Mexico.
In the Comstock award application, Steve Nadler, professor and chair of the Department of Entomology and Nematology, described Boudinot as “A highly respected scientist, teacher and leader with a keen intellect, unbridled enthusiasm, and an incredible penchant for public service.” Boudinot maintained a 4.00 grade point average and published 18 peer-reviewed publications on insect systematics, some landmark or groundbreaking work.
His most recent publications: one on Cretaceous Strepsiptera in Cladistics and the other on the iron maiden ants in Myrmecological News ("Two New Iron Maiden Ants from Burmese Amber (Hymenoptera:
Boudinot received multiple “President's Prize” awards for his research presentations at national ESA meetings. He organized the ESA symposium, “Evolutionary and Phylogenetic Morphology,” at the 2018 meeting in Vancouver, B.C. , and delivered a presentation on “Male Ants: Past, Present and Prospects” at the 2016 International Congress of Entomology meeting in Orlando, Fla.
Boudinot served on—and anchored—three of the UC Davis Linnaean Games teams that won national or international ESA championships. The Linnaean Games, now known as the Entomology Games, are a lively question-and-answer, college bowl-style competitions on entomological facts played between university-sponsored student teams.
Brendon served as president of the UC Davis Entomology Graduate Student Association from 2006 to 2019, and co-chaired the department's UC Davis Picnic Day celebration (with forensic entomologist Robert Kimsey) for three years.
Before enrolling in graduate school program at UC Davis in 2014, Brendon received his bachelor's degree in entomology in 2012 from The Evergreen State College, Olympia, Wash. Professor John T. Longino served as his mentor.