Cacti are famous for their ability to survive some of the harshest conditions on Earth, making them symbols of resilience in a warming world. But climate change is altering temperatures and rainfall patterns across many desert regions, highlighting the importance of understanding how these plants adapt.
Although cacti are often seen as slow-growing symbols of unchanging deserts, new research suggests they are evolving much faster than scientists once thought.
Researchers at the University of Reading in the U.K. set out to understand what drives the formation of new cactus species. For decades, biologists believed pollinators and highly specialized flowers were the main forces behind the development of new plant species. However, new research, which was recently published in the journal Biology Letters, found that cacti follow a different pattern. Instead of flower size or pollinator type driving diversification, the key factor appears to be how rapidly cactus flowers change shape over time.
Scientists analyzed flower measurements from more than 750 cactus species. Blooms ranged from just a tenth of an inch long to giant blossoms measuring more than 12 inches in diameter. Surprisingly, flower size itself had little connection to the appearance of new species.
Instead, cacti whose flowers evolved most rapidly were also the most likely to branch off into new species. The findings suggest that deserts, often viewed as harsh and unchanging landscapes, are actually places of rapid biological change.
With nearly one-third of cactus species threatened with extinction, understanding how quickly these plants evolve could help guide future conservation efforts.
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The cactus on your desk is an evolution speed machine
