Plants are ubiquitous in terrestrial environments and have been so for the last 400 million years, and a recent study by scientists at the University of Gothenburg demonstrates just how hardy the Kingdom Plantae is, Tech Times reports. Plants just don’t have negative rates of diversification (in which the number of species dying out is larger than new species emerging) for very long periods of time.
Scientists analyzed some 20,000 plant fossils to better judge the effects these events have had on plant diversity, and the evidence shows that mass extinctions have had diverse impacts among plant groups.
Periods where plant biodiversity was in decline, such as when older plant species died out quicker than new plant species were evolving, were short-lived, and that, the scientists say, is a good indicator of their ability to survive tough times and then recover.
“In the plant kingdom, mass extinction events can be seen as opportunities for turnover leading to renewed biodiversity,” says lead study author Daniele Silvestro, per Tech Times.
One of the most striking extinction events occurred during the Cretaceous-Paleogene mass extinction, which was caused by the impact of a massive asteroid off of the Mexican coast about 66 million years ago. The event drastically changed the configuration of terrestrial habitats and led to the extinction that killed off all dinosaurs except birds. What’s most surprising about this is that it’s effect on plant diversity was quite limited, R & D Mag reports.
Some major plant groups, like the gymnosperms — a group that includes pines, spruce, and firs — lost much of their diversity through extinction. Angiosperms, which are flowering plants, didn’t suffer much increased extinction, and it wasn’t long after the impact that they underwent a rapid increase in their diversity. This evolutionary proliferation allowed flowering plants to dominate today’s global diversity of plant groups.
“Mass extinctions are often thought as a bad thing, but they have been crucial in changing the world into how we know it today,” says Alexandre Antonelli, a senior author of the study.
If the asteroid hadn’t smacked into Earth, there’s a good chance that large dinosaurs might still be looking for bite-sized snacks, mammals would still be tiny, and humans might not have evolved, R & D Mag reports.
The results of the study, which were published in the journal New Phytologist, have relevance for our world today, Tech Times reports.
“By studying such extreme events we are trying to learn which groups of organisms and features are more sensitive to changes, so that we can apply this knowledge to protect biodiversity in the face of on-going climate change and human deterioration of natural ecosystems,” Antonelli says.
One thing is clear, plants are beautiful and remarkable in their diversity and some extinct forms were equally wonderful as well. One extinct family that is quite fascinating are the seed ferns.
What are seed ferns?
In appearance, these vascular plants, also known as pteridosperms, look rather like ferns–especially tree ferns. What makes this group notable however, is that unlike ferns, they produced seeds and are considered to be the first seed-bearing plants. Originating as far back as the Devonian period, with the evolution of seeds, these revolutionary plants brought about a major shift in plant evolution. While pteridosperms are now extinct, modern plants certainly owe much of their diversity to these and other pioneering plants that have helped proliferate the planet’s wondrous diversity.
