Cactus evolving faster than expected explained: The slowest-looking plant on Earth is evolving faster than scientists expected — here’s how
Researchers at the University of Reading have found that the secret behind this rapid evolution is not flower size, but how quickly cactus flowers change shape over time.
New research questions long-held ideas about plant evolution
For years, many scientists believed that pollinators and highly specialized flowers were the main reason new plant species evolved, Science Daily reports. Ideas associated with Charles Darwin’s work on orchids helped shape this idea.
But the new study found that cacti don’t follow the same pattern.
Researchers discovered that rather than flower size driving diversity, rapid flower evolution plays a much larger role in helping cactus species branch into entirely new forms.
Scientists examined more than 750 cactus species
The research team analyzed flower length data from more than 750 cactus species. The differences in flower sizes were huge.
While some cactus flowers were only 2 mm long, some reached 37 cm in length, creating a 185-fold difference in size. Despite this great diversity, flower length had almost no connection with the rate at which new species emerged.
What researchers consistently found was that cactus species with rapidly changing flower shapes were much more likely to evolve into new species throughout both recent and ancient evolutionary history, Science Daily reports.
Fast-changing flowers may explain cactus diversity
Researchers initially expected cacti with larger, more specialized flowers would produce more species. Instead, the study showed that flower size made little difference.
What was most important was how quickly the flowers developed over time.
Lead author Jamie Thompson, of the University of Reading, said many people think of cacti as slow-growing and unchanging plants, but the research shows that the cactus family is actually one of the fastest-growing groups of plants on Earth, Science Daily reports.
The findings also suggest that deserts may not be as stable as they appear. Scientists say that these environments may actually be places where rapid natural change and evolution occurs.
Findings may impact future cactus conservation
The researchers say the study may also have important conservation implications.
Because the evolution of flowers has helped establish cactus species over millions of years, scientists believe evolutionary speed could be an important part of future conservation efforts.
Rapid evolution does not automatically guarantee survival, especially as climate change continues to accelerate faster than many cacti can adapt, the researchers noted.
Rather than focusing on a single trait to predict risk, conservationists may need to examine how quickly different cactus species evolve.
New cactus database aims to support future research
The study also introduced a new Open Access database called CactEcoDB.
Developed over seven years by Jamie Thompson and ten co-authors from three continents, including six researchers from the University of Reading, the database combines information about the characteristics, habitats and evolutionary relationships of cacti, Science Daily reports.
The resource has been published in Nature Scientific Data and is expected to help researchers better understand cactus biodiversity and future conservation challenges.
Cacti continue to be one of the fastest diversifying plant groups
Researchers say there are approximately 1,850 known species of cactus. Over the last 20 to 35 million years, cacti have spread widely across the Americas.
New findings show that even plants known for their slow growth may be evolving rapidly behind the scenes.
FAQ
What did the new cactus study discover?
Scientists have found that cacti evolve surprisingly quickly and form new species.
Who conducted the research?
The study was carried out by researchers at the University of Reading.
