A new study by researchers at VIB and Ghent University suggests that flowering plants may have survived the asteroid impact that wiped out the dinosaurs because of genome duplication
Published in the journal Cell, the research explores how whole-genome duplication could have helped species endure periods of extreme environmental stress over millions of years.
Genome duplication is the process by which plants accidentally copy their entire genetic material.
Around 66 million years ago, an asteroid estimated to be the size of Mount Everest struck Earth, causing devastating environmental collapse. The event led to the extinction of all non-avian dinosaurs and wiped out roughly a third of all life on the planet. But many plants managed to survive this event.
Researchers now believe this is due to polyploidy, a condition in which plants possess more than the usual two sets of chromosomes. While humans and most animals carry two sets of chromosomes, many plants naturally carry extra copies. Bananas, for example, often have three sets, while wheat can have six.
These duplicated genomes can create challenges. Larger genomes require more energy and nutrients to maintain, increase the chances of harmful mutations, and can reduce fertility. Because of these disadvantages, most duplicated genomes disappear over time.
However, the extra genetic material can also provide important benefits. Duplicate genes can evolve new functions, helping plants adapt to difficult conditions such as drought, extreme heat, or rapid environmental changes.
Millions of years of evolution
To understand when and why genome duplications happen, the research team analysed the genomes of 470 flowering plant species, creating one of the largest datasets of its kind.
Scientists searched for matching blocks of genes that signal ancient whole-genome duplication events. They then compared those genetic patterns with evidence from 44 plant fossils to estimate when the duplications occurred.
The results revealed that many surviving duplicated genomes originated during periods of major environmental stress.
These periods included the asteroid-triggered mass extinction 66 million years ago, episodes of severe global cooling, and the Palaeocene-Eocene Thermal Maximum (PETM) around 56 million years ago.
The study suggests that during these unstable periods, plants with duplicated genomes may have been better equipped to survive changing conditions while other species disappeared.
What this means for today’s climate crisis
The research also offers insights into how modern plants could react to climate change.
During the PETM, global temperatures rose by 5-9 °C over approximately 100,000 years. Although today’s warming is happening far more quickly, scientists believe the ancient fossil and genetic records still provide valuable clues.
Plants with duplicated genomes could be better able to adapt to environmental stress, increasing their survival in the face of rising temperatures, shifting rainfall patterns, and ecosystem disruptions.
The findings highlight how evolutionary traits that may appear disadvantageous during stable times can become crucial survival tools during global crises.
As climate change accelerates, understanding these ancient survival mechanisms could help scientists identify which plant species are most resilient.
