Nature’s Great Survivors: Flowering Plants Sue
a New study Researchers from the University of Bath (UK) and the National Autonomous University of Mexico (Mexico) have shown that flowering plants survived relatively unscathed from the mass extinction that killed off the dinosaurs 66 million years ago. While they suffered the loss of some species, this devastating event helped flowering plants become the dominant type of plant today.
There have been many mass extinctions in Earth’s history, the most famous of which was caused by an asteroid impact 66 million years ago, which profoundly redirected the course of life on Earth.
The Cretaceous-Paleogene (K-Pg) extinction event wiped out at least 75% of all species on Earth including dinosaurs, but until now it has not been clear how much it affected flowering plants.
Plants do not have skeletons or exoskeletons like most animals, which means that fossils are relatively rare compared to animals, making it very difficult to understand the timeline of evolution from fossil evidence alone.
Dr. Jamie Thompson of the Milner Center for Evolution and Dr. Santiago Ramírez Barahona of the National Autonomous University of Mexico analyzed evolutionary trees created from mutations in the DNA sequences of up to 73,000 living species of flowering plants (angiosperms).
Using sophisticated statistical methods, they fitted “birth-death” models to estimate extinction rates over geological time.
While the fossil record shows that many species have already disappeared, the lineages to which they belong, such as families and orders, survived long enough to flourish and then dominate – of the approximately 400,000 species of plants living today, about 300,000 of them are flowering plants.
Molecular clock evidence suggests that the vast majority of angiosperm species that exist today existed before the K-Pg event: species including the ancestors of orchids, magnolias and mints all shared the land with dinosaurs.
Dr Jamie Thompson said: “After most species on Earth went extinct in K-Pg, angiosperms benefited, similar to how mammals took over after the dinosaurs, and now almost all life on Earth is ecologically dependent on flowering plants.”
So what made them strong enough to survive despite being unable to move and relying on the sun for energy?
Dr Ramírez Barahona said: “Flowering plants have a remarkable ability to adapt: they use a variety of seed dispersal and pollination mechanisms, some have completely copied their genomes, and others have developed new ways of photosynthesis.
“This flower power is what makes them true survivors of nature.”
The study is published in Biology letters The project was supported by donors Roger and Sue Horrod.
There is no evolutionary evidence for a mass extinction of angiosperms at the Cretaceous-Paleogene (K-Pg) boundary.
Date the article was published
September 13, 2023