Scientists just found DNA “supergenes” that speed up evolution
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Scientists just found DNA “supergenes” that speed up evolution
Date:
April 1, 2026
Source:
University of Cambridge
Summary:
Hidden within fish DNA are powerful genetic twists that may explain one of nature’s biggest mysteries: how new species form so quickly. In Lake Malawi, hundreds of cichlid fish species evolved at lightning speed, and scientists now think “flipped” sections of DNA—called chromosomal inversions—are the secret. These inversions lock together useful gene combinations, creating “supergenes” that help fish rapidly adapt to different environments, from deep waters to sandy shores.
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DNA “supergenes” may be the hidden engine behind nature’s rapid bursts of evolution. Credit: Shutterstock
Researchers have uncovered a powerful genetic mechanism that may help explain how some species evolve with surprising speed. Certain sections of DNA, known as "flipped" segments, appear to help fish rapidly adapt to new environments and even split into entirely new species. These genetic features act like evolutionary accelerators, preserving useful traits and speeding up change.
One of biology's biggest questions is how Earth became home to such a vast range of plants and animals. Cichlid fish in Lake Malawi, located in East Africa, provide a striking example. In this single lake, more than 800 species have emerged from a shared ancestor in far less time than it took humans and chimpanzees to diverge.
Even more remarkable, all of this diversification occurred within the same body of water. Some cichlids evolved into predators, while others specialized in feeding on algae, sifting sand, or consuming plankton. Each species carved out its own ecological role despite living side by side.
Scientists from the Universities of Cambridge and Antwerp set out to understand how this rapid burst of evolution was possible. Their findings were published in the journal Science.
The Discovery of Flipped DNA Segments
To investigate, researchers analyzed the DNA of more than 1,300 cichlid fish. They were searching for genetic features that could explain the unusually fast pace of evolution.
"We discovered that, in some species, large chunks of DNA on five chromosomes are flipped -- a type of mutation called a chromosomal inversion," said senior author Hennes Svardal from the University of Antwerp.
Under normal conditions, reproduction involves recombination, a process where DNA from both parents is mixed together. However, within these flipped regions, this mixing is blocked. As a result, groups of genes remain linked and are passed down intact from one generation to the next. This preserves combinations of traits that are already beneficial, allowing evolution to proceed more efficiently.
"It's sort of like a toolbox where all the most useful tools are stuck together, preserving winning genetic combinations that help fish adapt to different environments," said first author Moritz Blumer from Cambridge's Department of Genetics.
"Supergenes" and Rapid Adaptation
These linked gene clusters are often referred to as 'supergenes. In cichlid fish, they appear to play a major role in shaping species differences. Even though different species can still interbreed, these inversions limit how much their DNA mixes, helping maintain distinct traits.
This is especially important in areas where species overlap, such as open sandy regions of the lake where there are no clear physical boundaries separating habitats.
Many of the genes within these supergenes influence traits essential for survival and reproduction, including vision, hearing, and behaviour. For instance, fish that live deep underwater (down to 200 meters) must cope with low light, high pressure, and different food sources compared to those near the surface. Their supergenes help preserve the specific adaptations needed for those conditions.
"When different cichlid species interbred, entire inversions can be passed between them -- bringing along key survival traits, like adaptations to specific environments, speeding up the process of evolution," said Blumer.
A Broader Role in Evolution
Chromosomal inversions do more than preserve helpful traits. They can also function as sex chromosomes, influencing whether an individual develops as male or female. Because sex determination plays a role in how species form, this adds another layer to understanding evolution.
"While our study focused on cichlids, chromosomal inversions aren't unique to them," said co-senior author Professor Richard Durbin, from Cambridge's Department of Genetics. "They're also found in many other animals -- including humans -- and are increasingly seen as a key factor in evolution and biodiversity."
Researchers believe these findings could help answer a long-standing question about how life diversifies so rapidly under the right conditions.
"We have been studying the process of spe