More than one-fifth of the evolutionary history of the world’s flowering plants is at risk of extinction, according to a new study.

This loss represents a significant threat to global biodiversity. When entire evolutionary lineages vanish, the world loses unique genetic information and biological traits that cannot be recovered, potentially destabilizing ecosystems that rely on these plants for survival.

The research was conducted by scientists from the Royal Botanic Gardens, Kew, and the Zoological Society of London. Lead author Rachel Faber and her team analyzed the global distribution of flowering plants to determine how much of their ancestral history is currently threatened [1], [2].

The study found that over 20% of this evolutionary history is at risk [1], [2]. Unlike traditional extinction counts that focus on the number of species, this approach measures the length of time a lineage has existed independently. The loss of a species that is the sole survivor of an ancient lineage is viewed as a greater evolutionary loss than the loss of one of many closely related species.

Researchers identified several primary drivers behind these threats. Habitat loss and climate change are cited as the main extinction pressures pushing these plants toward the brink [1], [2]. As environments shift or are destroyed by human activity, plants that have evolved over millions of years to fit specific niches are unable to adapt quickly enough to survive.

The findings highlight a critical gap in conservation efforts. While many programs focus on high-profile species, the researchers said that protecting evolutionary distinctness is essential for maintaining the resilience of the planet's flora [1], [2].

“Over 20% of the evolutionary history of the world’s flowering plants is at risk of extinction.”

This study shifts the conservation focus from simple species counts to 'phylogenetic diversity.' By quantifying the loss of evolutionary history, scientists can better identify which plants are irreplaceable. This suggests that current conservation strategies may be underestimating the impact of extinction if they do not account for the age and uniqueness of the lineages being lost.