A new evolutionary analysis suggests the behavior appears across many bird groupsA new evolutionary analysis suggests the behavior appears across many bird groupsIn the intricate dance of life’s blueprint, DNA has long been celebrated as the master code guiding organismal development and heredity. Yet, the regulation of gene activity—how genes switch on and off with exquisite precision across different cellular contexts and environmental cues—extends beyond the mere sequence of nucleotides. This regulation hinges on a complex layer of control known as epigenetics. Epigenetics encompasses chemical modifications of DNA and histone proteins that influence gene expression without altering the underlying genetic code. Among these modifications, DNA methylation, the addition of methyl groups to cytosine bases within the genome, has emerged as a pivotal mechanism modulating gene activity.
In vertebrates such as mammals, a robust epigenetic “resetting” occurs shortly after fertilization. This sweeping reprogramming strips away most inherited methylation marks, effectively erasing epigenetic memories acquired during the parents’ lifetimes and thus safeguarding embryonic development from potentially deleterious epimutations. However, this epigenetic reprogramming does not appear universal across the animal kingdom. In numerous invertebrates, including marine organisms like corals, worms, sea anemones, and sea urchins, this global erasure seems conspicuously absent, hinting at fundamental evolutionary divergences in epigenetic regulation.
A groundbreaking study recently explored these differences by experimentally disrupting DNA methylation in the starlet sea anemone, Nematostella vectensis, a cnidarian species that occupies a key phylogenetic position near the base of animal evolution. By selectively removing methylation marks within its genome, researchers sought to unravel methylation’s functional importance in an organism where typical epigenetic resetting is missing. Contrary to expectations, the anemones developed normally, even in the near complete absence of DNA methylation. This surprising resilience suggested that DNA methylation’s primary role might not be to orchestrate gene expression as traditionally envisioned.
Rather than broadly compromising gene regulation, the loss of methylation predominantly unleashed the activity of transposable elements—often referred to as “jumping genes” or selfish DNA sequences—that reside within actively transcribed genes. These genetic elements possess the capacity to move within the genome, potentially inserting themselves into critical coding or regulatory regions. If not tightly suppressed, such mobilization can disrupt gene function, precipitate genomic instability, and impair normal development. The discovery that methylation chiefly acts to restrain these disruptive elements underscores an ancestral genomic defense mechanism preserved across evolutionary epochs.
Dr. Alex de Mendoza, a leading expert in evolutionary epigenomics at Queen Mary University of London, highlighted the profound implications of these findings. Because invertebrate species like sea anemones lack the typical epigenetic cleansing during early development, abnormal methylation patterns can persist and transmit to subsequent generations. This epigenetic inheritance modulates gene expression profiles beyond what genetic code alone dictates, revealing an additional layer of heritable biological information. Such phenomena demonstrate how experimentally introduced epigenetic variation can traverse generational boundaries in animals, challenging the long-held tenet that only DNA sequence changes are heritable.
Delving deeper, the research offers a novel perspective on the evolutionary trajectory of DNA methylation. Initially, this modification appears to have evolved primarily as a genomic safeguard, protecting coding sequences from the disruptive capacity of transposable elements. Over time, in mammalian lineages, this molecular machinery was co-opted and expanded to execute broader developmental regulatory roles—acting to silence one X chromosome in females and regulate complex tissue-specific gene expression programs. The study thus illuminates how molecular systems adapt and diversify, transforming ancient genomic guardians into sophisticated regulators of vertebrate biology.
Moreover, the lack of full epigenetic reprogramming in cnidarians suggests these organisms possess an inherent capacity to maintain inherited epigenetic states, providing a reservoir of variation for natural selection to act upon. Such stable transmission of epigenetic marks without underlying genetic mutation may represent an unappreciated source of phenotypic diversity and evolutionary innovation. This challenges the paradigm that heritable biological change requires DNA sequence alteration, expanding evolutionary biology’s conceptual framework to include epigenetic mechanisms in shaping organismal adaptation.
This work also emphasizes the intricate interplay between epigenetics and genome integrity. Transposable elements constitute a significant fraction of animal genomes, and their regulation is paramount to preventing genomic chaos. DNA methylation emerges as a critical regulator, keeping these elements silenced, especially within gene bodies, where their disruptive potential is highest. The failure of this epigenetic control unleashes internal genomic parasites that can jeopardize normal gene function and organismal survival.
Intriguingly, the seemingly paradoxical normal development of methylation-deficient anemones underscores redundancy and plasticity in gene regulatory networks. The absence of overt developmental defects suggests that alternative mechanisms can compensate for lost methylation-mediated repression. This resilience hints at a genome architecture finely tuned through evolution to maintain stability even when key regulatory systems falter, underscoring the robustness of biological systems.
The study not only deepens our understanding of DNA methylation’s ancestral functions but also opens avenues for exploring how epigenetic inheritance influences ecological and evolutionary dynamics in marine ecosystems. Cnidarians represent ecologically vital keystone species; thus, their capacity to pass on epigenetic traits may impact resilience and adaptation in changing oceans, with implications for biodiversity and conservation.
Beyond evolutionary insights, the research sets a foundation for new epigenetic models that integrate heritable methylation patterns with genome defense and gene regulation. It challenges researchers to reconsider the boundaries between genetic and epigenetic inheritance and to explore how ancient molecular mechanisms continue to shape life’s diversity from sea anemones to humans. This deeper comprehension may ultimately inform biomedical approaches targeting epigenetic modifications in disease and developmental biology.
In sum, this landmark investigation redefines DNA methylation’s evolutionary purpose, positing that its primordial function was genome protection rather than gene regulation per se. The delicate dance between epigenetic marks, transposable elements, and genetic regulation emerges as a foundational axis steering animal evolution and developmental fidelity. As we dive deeper into epigenomes across diverse species, the revelations from humble sea anemones remind us that evolution often innovates by repurposing age-old molecular tools in unexpected, transformative ways.
Subject of Research: Not applicable
Article Title: Gene body methylation suppresses intragenic transcription and permits epigenetic inheritance in a cnidarian
Web References: 10.1038/s41559-026-03090-6
Image Credits: Karmannye Chaudhary
Keywords: Evolutionary biology, epigenetics, DNA methylation, transposable elements, epigenetic inheritance, cnidarian, genome stability, gene regulation, Nematostella vectensis
How do you determine how many months or years animal mothers nurse their babies? If you’re not in a rush and can observe this dynamic, you could supposedly stick around to see when the baby, mother, or both decide that they’re done. However, that could take years. A team of researchers investigating breastfeeding in orangutans recently opted for a different, perhaps surprising strategy—searching for particular proteins in poop.
In a preliminary study published in the journal Communications Biology, researchers searched for milk‑specific proteins in the feces of wild Bornean orangutans (Pongo pygmaeus) living in the Danum Valley Conservation Area, in the Malaysian part of the island of Borneo. These proteins prove that he or she is continuing to drink breast milk.The practice of recognizing particular proteins in feces is called fecal proteomics and it can help scientists better understand what animals are consuming.
“Orangutans have a slow life history with one of the longest interbirth intervals and the lowest reported infant mortality rates among primates or even mammals,” the team wrote in the study. “Breastfeeding is a key factor in their life history because it possibly promotes offspring health and increases maternal interbirth intervals.”
The team gathered fecal samples for over two and a half years, and found milk‑specific proteins in all the 20 samples from orangutans less than six and a half years old. This indicates that the young great apes were continuing to breastfeed until they were at least that age.
According to the team, these results are “consistent with the behavioral evidence as having one of the longest breastfeeding periods in mammals.”
What’s more, “milk intake was significantly correlated with higher levels of biological defense and probiotic bacterial proteins.”
In other words, the more milk a young orangutan drinks, the more probiotic intestinal bacteria it has and the sturdier its biological protections are. Such consistent and enduring breastfeeding probably helps the very high survival of orangutan babies and plays a role in their slow reproductive approach.
Unfortunately, Bornean orangutans are critically endangered, and the paper highlights why their populations don’t rebound quickly after a decrease. Safeguarding what’s left of their rainforest habitats is crucial.
The post Orangutan poop holds surprising clues about how long they breastfeed appeared first on Popular Science.
Built to track enemy submarines, the Navy’s underwater listening network inadvertently revealed that whales may be singing across entire oceans.Built to track enemy submarines, the Navy’s underwater listening network inadvertently revealed that whales may be singing across entire oceans.The New York Times described the stunning behavior over 100 years ago.A barn owl’s ability to hunt by hearing alone relies on exquisite variations in the structure of its feathers.Saving Gilbert’s potoroo means finding habitats rich in the underground fungi it eats.
Snakes saw a burst of adaptation about 128 million years ago that led to them exploding in diversity and evolving up to three times faster than lizards
© Alejandro Arteaga/Khamai Foundation
Chimpanzee “helicopter moms” often protect their offspring from bullies, but bonobo moms are more hands-off
© Fiona Rogers/Getty Images
Charlotte, a stingray in a small North Carolina aquarium, is taking a DIY approach to reproduction
© Luis Diaz Devesa/Getty Images
What sets humans apart from other animals is our ability to create culture; however, a new study from the Max Planck Institute of Animal Behavior focusing on chimpanzees is challenging how researchers define culture in the animal kingdom.
Digging deeper into chimpanzee behavior, the new findings indicate that wild chimpanzees learn dozens of everyday behaviors from one another, many of which are essential for survival but have not traditionally been recognized as “cultural.”
The study took place in the Budongo Forest region at the Budongo Conservation Field Station in Uganda. Over two years, the team followed 28 wild chimpanzees of different ages, recording more than 1,000 hours of detailed observations of their daily behavior.
“Animal culture doesn’t have to be rare or complex. It can include basic skills used every day, like finding food and knowing how to eat it,” says first author Nora Slania from the Max Planck Institute of Animal Behavior in a statement.
Researchers focused on a behavior called “peering,” in which one chimpanzee closely watches another’s actions. This attention-based learning technique has been studied in other primates, but its broader role in chimpanzee cultural transmission had not been fully explored. The team documented 366 instances of peering and found that chimpanzees selectively observed others during important learning moments, such as when acquiring complex or rare skills.
“In humans, our everyday lives are full of culture, including the way we speak, dress, or eat. We don’t require behaviors to be especially remarkable or independent of our environment,” says Dr. Caroline Schuppli, senior author of the study.
“Animals, however, have long been held to stricter standards. By adopting a more inclusive view of culture—and standards more comparable to those applied to humans—future research may reveal that many animals possess richer cultures than previously recognized,” she adds.
During the long-term observations, the research team identified 69 distinct behaviors that chimpanzees appeared to learn socially. Surprisingly, only a small subset of those behaviors would have been classified as cultural under previous definitions. Most of the observed activities involved feeding, grooming, playing, and basic environmental exploration.
One of the study’s most important findings involved the central role food plays in chimpanzee culture. Around 60% of the observed behaviors involved identifying, processing, or consuming plant foods such as fruits and leaves. These observations suggest chimpanzees rely not only on instinct, but also on social learning through “peering” to locate and process food sources.
Notable researchers such as Jane Goodall previously linked chimpanzee culture primarily to tool use, identifying 39 cultural behaviors across chimpanzee populations. However, the new findings suggest that a narrower definition may have underestimated the true scale of cultural learning in chimpanzees.
“The fact that so much of a chimpanzee’s diet is socially learned highlights how important social learning is for their development,” Schuppli said in a statement.
“While some behaviors may be simple and learned quickly, acquiring the full range of their culture still takes young chimpanzees many years,” she adds.
These everyday practices are very similar to human culture, like eating habits, communication styles, and social norms. The study proposes that chimpanzee culture is more continuous and embedded in daily life than previously recognized.
“Behavior allows animals to respond flexibly to the world around them, and cultural transmission offers a fast way to learn new behaviors. Ultimately, understanding the full scope of animal culture will help us protect the diverse ways these species adapt to changing environments,” Slania added
This study was previously published in iScience.
Chrissy Newton is a PR professional and the founder of VOCAB Communications. She currently appears on The Discovery Channel and Max and hosts the Rebelliously Curious podcast, which can be found on YouTube and on all audio podcast streaming platforms. Follow her on X: @ChrissyNewton, Instagram: @BeingChrissyNewton, and chrissynewton.com. To contact Chrissy with a story, please email chrissy @ thedebrief.org.
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