On October 24, the fifth cohort of graduates from the Museum’s Richard Gilder Graduate School—the first Ph.D.-degree-granting program for any museum in the Western Hemisphere—received Doctor of Philosophy degrees in Comparative Biology at a commencement ceremony in the Milstein Hall of Ocean Life. We're profiling the newly minted Ph.D.s.
With some 1.8 million people, the city of Vitória on Brazil’s coast is no nature reserve. So when Bernardo Santos was growing up there, he channeled his love for animals into those that were “at hand”: insects. Santos’s father was a beekeeper, and Bernardo helped with the bees. He also had a butterfly board, where he’d collect and pin specimens representing the diverse species that he’d found flying through the hilly streets and avenues of Vitória.
Santos studied at Universidade Federal do Espírito Santo in his home town, earning both his Bachelor’s and Master’s degrees, and where he later worked as a university lecturer, teaching subjects ranging from cell biology to paleontology to undergraduate students before moving to New York to start his doctoral studies at the Museum’s Richard Gilder Graduate School (RGGS). His primary advisor was Peter J. Solomon Family Curator in the Division of Invertebrate Zoology and RGGS professor James Carpenter.
The wide world of so-called parasitoid wasps would become his domain while he worked toward his Ph.D. Unlike eusocial bees and ants, which are highly socially organized and live in colonies (as do some members of one family of wasps, the Vespidae), most wasp species live solitary lives, coming together only to mate. Parasitoid wasps, of which there are over 70,000 known species (more than all species of vertebrates), are far more common.
They are also, says Santos vividly, “like Ridley Scott’s Alien!”
Female parasitoid wasps lay eggs in the bodies of other insects or arachnids. There, the eggs grow and develop into larvae, which consume their unlucky hosts from the inside. Then, the larva pupates—that is, grows larger and spins a cocoon for itself, in which to continue to develop and grow before metamorphosing to emerge from the cocoon as an adult wasp.
While parasitoid behavior may seem unusual, Santos points out that it evolved much earlier than the sociality we associate with insects like bees and ants. Amazingly, a species of parasitoid wasp exists to prey upon nearly every other species of insect and of many of their arachnid relatives.
“These wasps are the single most effective insect-population control in nature,” says Santos.
Santos’s passion for describing previously unknown species of wasps drove his fieldwork and studies at the RGGS. He traveled far and wide, into field sites and museum collections alike, to identify new species. By examining collections around the world, he already has described almost a hundred new species of parasitoid wasps during his young career.
In describing one of these new species, Santos worked with public school 6th-graders in New York’s Washington Heights neighborhood to choose its new name. Together, they landed on the name “La luz brilliante” or “the brilliant light” which became part of its official scientific Latin name, Nesolinoceras laluzbrillante.
He was inspired to undertake this special type of outreach by his time at the Museum, where he also had the opportunity to mentor two high-school students in the AMNH’s Science Research Mentorship Program, who studied an Andean species of wasp. In his four years at RGGS, Santos also spent extensive time in the molecular lab, sequencing DNA for hundreds of species of parasitoid wasps.
Using those DNA data to unravel the evolutionary history of these wasps, and building an “evolutionary family tree”; measuring and photographing specimens, and then using statistical tools to quantify their similarity in shape. By combining shape data with evolutionary history, Santos was able to understand how different modes of parasitism (using different hosts, etc.) influenced the evolution of their body shapes.
Following commencement, Santos will continue his scientific research on parasitoid wasps as a Peter Buck Postdoctoral Researcher at the Smithsonian National Museum of Natural History, in Washington, D.C.