Thursday, July 16, 2026

Scientists find hidden individuality in viral infections

A new study reveals that viruses exhibit substantial differences in how they shape the fate of host cells, with implications for ecology, evolution and biotechnology

University of Maryland

An international team of researchers developed a new way to uncover hidden differences in how viruses infect and destroy individual microbial cells—solving a biological puzzle that has persisted for more than 80 years.

For decades, researchers have focused on answering a key question: What happens inside a single infected cell before that cell bursts open to release a new generation of viruses? To answer the question, they typically measure two traits—how long the virus takes to rupture the cell and how many new viruses are released—which are estimated as population averages, masking potentially important differences from one infected cell to the next.

In a new University of Maryland-led study embargoed until publication at 2 p.m. ET on July 15, 2026, in the journal Science Advances, researchers showed for the first time that they could accurately predict hidden cell-to-cell variation in infection outcomes using population-level cell measurements.

“Individual infections do not unfold the same way,” said the paper’s senior author Joshua Weitz, a professor of biology at UMD with a joint appointment in the University of Maryland Institute for Health Computing. “Successfully quantifying that variation at the level of a single cell opens the door to developing predictive models of how viruses can be used therapeutically to confront drug-resistant pathogens and how viruses transform environmental health.”

A precise prediction model

The researchers used a mathematical modeling framework developed over the past decade by Weitz’s group to analyze how viral populations accumulate over multiple rounds of infection. Leveraging subtle signals in large-scale patterns, the model inferred what was happening inside individual cells—including variation in the timing of the cell rupture when new viruses are released.

To test those predictions, collaborators in the lab of Debbie Lindell, a professor of biology at the Technion - Israel Institute of Technology, developed a single-cell experimental assay that directly measured infection outcomes in individual cells.

The experiments used bacteriophages, also known as phages, which are viruses that infect bacteria. Though invisible to the naked eye, phages are among the most abundant biological entities on Earth and play a crucial role in shaping microbial populations, nutrient cycling and ecosystem health. Phages are also increasingly evaluated and used therapeutically to target and clear infections caused by antibiotic-resistant bacteria.

The researchers focused on a marine phage-bacteria pair: a specific type of phage that infects abundant open ocean bacteria that fix carbon via photosynthesis. Viral infections of these cyanobacteria impact carbon cycling at global scales, making them ecologically important.

The results showed that the mathematical model’s predictions were strikingly accurate. The researchers found that the timing of cell rupture varied substantially from one infected cell to another in this phage-bacteria pair.

“Our findings contribute to solving an 80-year-old mystery on the sources of phenotypic variability in bacteriophages and advance the understanding of a core principle of the biology of viruses,” said the paper’s first author Marian Dominguez-Mirazo, who recently earned her Ph.D. in quantitative biosciences from the Georgia Institute of Technology.

Timing is (almost) everything

The researchers also uncovered a surprising new relationship between how long a virus remains inside a cell and how many offspring it produces.

Though earlier studies of synthetically controlled viral infections proposed that virus production would quickly level off as infections progressed, Weitz noted that his team didn’t see that happen.

“That’s not what we found,” said Weitz, who also holds the Clark Leadership Chair in Data Analytics at UMD. “Instead, we saw a piecewise linear relationship. Viruses generally kept producing offspring in proportion to the duration of infection, suggesting that viruses burst cells at different moments, often long before they run out of usable resources.”

That finding helps explain another mystery first identified by Nobel laureate Max Delbrück in his pioneering work on bacteriophage biology in the 1940s: Why does the number of viruses released from infected cells vary so dramatically?

The new work shows that much of that variation can be explained by differences in how long a virus takes to rupture the cell, which suggests that viral timing, both its average and its variability, may itself be shaped by evolution.

The study bridges microbiology, ecology, evolutionary biology and mathematical modeling, Weitz said, “offering a new way to understand not just average viral behavior, but the hidden diversity of infection outcomes occurring one cell at a time.”

Beyond advancing principles of virology, these findings provide an important new quantitative tool for studying and predicting the spread of viral infections in systems where direct single-cell measurements are difficult or impossible.

“Because viruses that infect microbes influence everything from ocean ecosystems to bacterial disease dynamics, understanding the hidden variation of viral traits could improve predictive models in environmental science, microbiology and emerging therapeutic applications,” Weitz said.

***

The paper, “Inferring single-cell heterogeneity of bacteriophage lysis-associated life-history traits from population-scale dynamics,” by Marian Dominguez-Mirazo, Ran Natan, Shay Kirzner, Debbie Lindell, and Joshua Weitz, is in press. It will be published in Science Advances on July 15, 2026, under doi 10.1125/sciadv.6456.

This research was supported by the Simons Foundation Life Sciences Program (Award Nos. 735081, 529554 and 722153). This article does not necessarily reflect the views of this organization.

Journal

Science Advances

DOI

10.1126/sciadv.aed6456

Method of Research

Experimental study

Subject of Research

Cells

Article Title

Inferring single-cell heterogeneity of bacteriophage lysis-associated life-history traits from population-scale dynamics

Article Publication Date

15-Jul-2026

CUNY Graduate Center research helps confirm discovery of new African monkey species

Anthropology Professor Christopher Gilbert and collaborators identify one of the first new African monkey species described in more than 75 years

The Graduate Center, CUNY

S1_video_congoensis — video:
Colobus congoensis, known locally as “likweli,” has deep resonant roaring calls that resemble those of related Colobus species but possesses a distinct acoustic structure.
view more
Credit: Bernard Bonanga

NEW YORK (July 15, 2026) — A team of researchers led in part by Christopher Gilbert, professor of anthropology at the CUNY Graduate Center and Hunter College, has confirmed the discovery of a previously unknown species of African monkey in the rainforests of the Democratic Republic of Congo (DRC), marking one of the most significant primate discoveries in decades.

The new species, Colobus congoensis, known locally as the Likweli, is only the fifth new monkey species identified in Africa in the past 75 years. The findings, published in PLOS One, are the culmination of years of international collaboration combining genetics, anatomy, field observations, and local ecological knowledge to establish the monkey as a distinct evolutionary lineage.

For Gilbert, the discovery builds on more than a decade of research in the Congo Basin. He also played a central role in confirming the discovery of the Lesula (Cercopithecus lomamiensis), another monkey species identified in the same region in 2012.

"When a potential new species is discovered, the evidence has to be overwhelming," said Gilbert. "We analyzed museum collections and comparative datasets, examining skulls, pelts, and skeletal anatomy alongside specimens from known African colobus monkeys. Those comparisons allowed us to demonstrate conclusively that Colobus congoensis represents a distinct species."

Gilbert led the anatomical analyses with longtime collaborator Eric Sargis, a Yale University professor and CUNY Graduate Center Ph.D. alumnus. They were joined by Julia Arenson, who was then a doctoral student at the Graduate Center. Arenson had assembled one of the most comprehensive comparative datasets on colobus monkey anatomy as part of her dissertation research, providing critical evidence that helped distinguish the new species from all other African colobus monkeys.

The team's anatomical research began in 2022 after field researchers recovered specimens that allowed detailed scientific comparisons. Using extensive collections from the Yale Peabody Museum and the American Museum of Natural History, along with Arenson's newly compiled database of skull measurements and Gilbert's comparative analyses of pelts and skeletal remains, the researchers established the formal anatomical diagnosis required to describe the species.

The discovery stems from a mystery that began in 2008, when researchers photographed an unusual monkey in the forests between the Lomami and Congo (Lualaba) rivers in east-central DRC. A clearer observation a decade later prompted an international investigation involving researchers from Florida Atlantic University, the Lukuru Wildlife Research Foundation, Yale University, the CUNY Graduate Center and Hunter College, Lomami National Park, and the Frankfurt Zoological Society.

Genetic analyses confirmed that C. congoensis belongs to the genus Colobus while revealing that it diverged from its closest known relative, Colobus satanas, approximately 4 to 5 million years ago. Anatomical evidence generated by Gilbert, Arenson, and their collaborators independently confirmed the species' distinctiveness.

The monkey is immediately recognizable by its glossy black coat, long cape-like fur, sweeping tail, and striking orange-cream facial markings. Weighing about 15 pounds, it is smaller than its closest relatives and possesses distinctive cranial, dental, and skeletal characteristics that separate it from every other known African colobus monkey.

The researchers also documented the species' unique vocalizations and worked closely with local communities to understand its distribution and behavior. Between 2018 and 2022, the team recorded just 114 sightings across an estimated range of approximately 1,700 square kilometers.

That limited distribution raises conservation concerns. The researchers propose that Colobus congoensis be classified as Endangered because of its restricted range, habitat loss, and hunting pressure. Most of its known habitat lies within Lomami National Park, making protection of the region critical for the species' survival.

"We continue to be reminded that the Congo Basin remains one of the world's last great frontiers for mammal discovery," said John A. Hart, first author of the study and a conservation scientist with the Lukuru Wildlife Research Foundation. "Even in regions that have been scientifically explored, entirely new species are still coming to light. This discovery reinforces how much

Striking new species of African monkey discovered deep in the Congo rainforest

Florida Atlantic University

C. Congoensis — image:
A photograph of Colobus congoensis, whose common name is the local vernacular name, “likweli.”
view more
Credit: Daniel Rosengren

In the rainforests of the Democratic Republic of Congo (DRC), scientists have identified a previously unknown species of African monkey – one of the rarest discoveries in modern primatology.

Named Colobus congoensis and known locally as “Likweli,” the monkey, which is mainly black with striking orange face patches is only the fifth new monkey species identified in Africa the last 75 years. Hidden within a remote region of the Congo Basin, the species remained undocumented despite decades of scientific exploration in Central Africa.

The mystery of this new species began with an unexpected sighting in 2008, when researchers captured a partially obscured photograph of the monkey. A decade later, researchers encountered the animal again and obtained a much clearer image. That discovery sparked further investigation into the elusive primate.

Now, new genetic, anatomical and acoustic analyses have confirmed that the monkey represents a distinct evolutionary lineage that diverged from its closest known relative 4 to 5 million years ago. The findings, published in PLOS One, also suggest the species may already be at risk because of its limited range, habitat loss and hunting pressure.

The discovery was made by an international team of scientists from Florida Atlantic University, the Lukuru Wildlife Research Foundation, Yale University, the City University of New York, as well as Lomami National Park, Frankfurt Zoological Society.

The mysterious monkey was found in the remote interfluve between the Lomami and Congo (Lualaba) rivers in east-central DRC, one of Central Africa’s most biologically significant regions.

“This discovery is both exciting and deeply personal, highlighting the extraordinary biodiversity of my homeland and how much remains undocumented,” said Junior Amboko, co-corresponding author, a Ph.D. student in the Department of Biological Sciences in FAU’s Charles E. Schmidt College of Science and a National Geographic Explorer. “I was honored to name the species ‘Colobus congoensis,’ recognizing the Congo Basin’s remarkable natural heritage and, we believe, marking the first primate named after the Democratic Republic of Congo itself – underscoring both its global importance and local pride.”

Draped in glossy black fur with cape-like shoulders, a long sweeping tail and a vivid orange-cream patch around the mouth and nose, C. congoensis has a striking, mask-like appearance unlike any other known colobus monkey. Smaller than related colobus monkeys – about 15 pounds – it is distinguished by sleek, light-reflecting fur and dramatic facial features created by long black facial hairs and large folded ears. White perianal markings further distinguish this species.

The discovery of C. congoensis also emphasizes the scientific importance of the Lomami National Park and its buffer zone in the DRC, which previously yielded another major primate discovery in 2012 by several members of this research team: the Lesula (Cercopithecus lomamiensis).

“We continue to be reminded that the Congo Basin remains one of the world’s last great frontiers for mammal discovery,” said John A. Hart, first author and a conservation scientist with the Lukuru Wildlife Research Foundation. “Even in regions that have been scientifically explored, entirely new species are still coming to light. This discovery reinforces how much biodiversity remains undocumented in the Central Congo Basin and how this region continues to reshape our understanding of primate evolution and conservation.”

Genetic analyses confirmed that C. congoensis belongs to the genus Colobus but also revealed an unexpected evolutionary connection.

“The discovery of Colobus congoensis is reshaping our understanding of African monkey evolution,” said Kate Detwiler, Ph.D., senior and corresponding author and an associate professor of biological sciences in FAU’s Charles E. Schmidt College of Science. “Its closest known relative is Colobus satanas, found more than 1,200 kilometers away in west-central Africa. Yet our genetic evidence shows the two species diverged roughly 4 to 5 million years ago, marking one of the oldest known evolutionary splits within the Colobus lineage.”

Anatomical analyses played an instrumental role in confirming C. congoensis as a distinct species and establishing the physical characteristics that set it apart from other African colobus monkeys.

“We compared the skulls and pelts of C. congoensis with other species of African colobines, which underscored how unique this new species is,” said Julia L. Arenson, Ph.D., co-author and a postdoctoral associate at the Yale Institute for Biospheric Studies, who had a very large collection of skeletal data related to her Ph.D. thesis on colobus monkeys. “At the same time, despite being much smaller in body size, we also demonstrated it shares features of the teeth, skull and face with Colobus to the exclusion of other African colobines.”

The cranial and dental findings corroborated the genetic evidence and helped researchers establish the formal anatomical diagnosis required to validate the species.

“In order to name a new species, you have to be able to prove it,” said Christopher Gilbert, Ph.D., co-author and an anthropology professor with the City University of New York Graduate Center and Hunter College. “We used extensive museum collections including specimens housed at the Yale Peabody Museum and the American Museum of Natural History, and comparative datasets to compare the skulls and pelts with known African colobus monkeys. This robust pool of information allowed us to pretty quickly and conclusively confirm C. congoensis as a new species.”

The newly identified primate is not only genetically and anatomically distinct from other African colobus monkeys but is further distinguished by its vocalizations. Its deep, resonant roaring calls resemble those of related Colobus species but possess a distinct acoustic structure.

Researchers also incorporated local ecological knowledge to better understand the species’ distribution and behavior, speaking with residents and hunters across villages in the Lomami National Park’s buffer zone. Only eight villages recognized the species or could accurately describe it. Local communities referred to the monkey as “Likweli” and “kasaba nkoni,” the latter meaning “the branch shaker,” and described it as elusive and rarely seen.

Between 2018 and 2022, researchers recorded 114 sightings across an estimated range of just 1,700 square kilometers – an unusually small range for colobus monkeys. C. congoensis appears naturally isolated by rivers and forest barriers and dependent on scattered upland forest patches in the Congo Basin.

But even as the species enters the scientific record, researchers warn it may already be at risk. Because of its extremely limited range, small population size, growing hunting pressure and ongoing habitat loss, scientists are proposing C. congoensis be classified as Endangered on the IUCN Red List. Most of its known habitat lies within Lomami National Park, making protection of the region critical to the species’ survival.

“The discovery of Colobus congoensis is both a scientific triumph and a sobering reminder that some of Earth’s rarest creatures may vanish before the world even knows they exist,” said Detwiler.

Study co-authors are Emma R. Horton and Kathryn F. Coates, FAU’s Department of Biological Sciences; Jean-Pierre Kapale, Lukuru Wildlife Research Foundation and Lomami National Park, Frankfurt Zoological Society; Mardoché B. Koko, Lomami National Park, Frankfurt Zoological Society; Terese B. Hart, Ph.D., Lukuru Wildlife Research Foundation; and Eric J. Sargis, Ph.D., Yale University, Yale Peabody Museum, and Yale Institute for Biospheric Studies.

- FAU -

About Florida Atlantic University:

Florida Atlantic University serves more than 32,000 undergraduate and graduate students across six campuses along Florida’s Southeast coast. Recognized as one of only 13 institutions nationwide to achieve three Carnegie Foundation designations - R1: Very High Research Spending and Doctorate Production, Opportunity College and University, and Carnegie Community Engagement Classification - FAU stands at the intersection of academic excellence and social mobility. Ranked among the Top 100 Public Universities by U.S. News & World Report, FAU is also nationally recognized as a Top 25 Best-In-Class College and cited by Washington Monthly as “one of the country’s most effective engines of upward mobility.” To learn more, visit www.fau.edu.