Frequent Volcano Eruptions Can Wipe Out Plant Species, But Also Help Them Evolve and Thrive

Earth’s long volcanic history has physically shaped the terrain and brought about the demise of some species. For example, on the volcanic island of Nishinoshima, Japan, volcanic activity has wiped out a species of purslane, a common plant.

While extinction typically has a negative connotation, in this case, researchers could study how life grows and evolves from its earliest stages in a brand new environment. In the case of the extinct purslane, the research team traced its origins and found a quirky surprise along the way. The findings have been published in Plant Systematics and Evolution.

Read More: Activity at Alaska’s Mount Spurr Suggests That The Volcano Is About To Erupt

Frequent Volcanic Eruptions

Nishinoshima Island is part of the Ogasawara Island chain, which is about 600 miles south of Tokyo. The island is home to frequent volcanic eruptions that nearly wipe out most plant life each time. Before a 2019 eruption that led to the native purslane's extinction, researchers from Tokyo Metropolitan University extracted a few purslane plants and brought them back to their lab.

The purslane — Portulaca oleracea — is found in other tropical regions across the globe. However, according to the researchers, on Nishinoshima Island, it is now extinct.

The research team began a genetic analysis of the Nishinoshima Island purslane and compared it to purslane collected across various parts of Japan and Guam. Through this analysis, the team discovered where this specific purslane fell on the Portulaca oleracea phylogenetic tree.

Purslane Experienced Founder Effect

Example of a phylogenetic tree

(Image Credit: VectorMine/Shutterstock)

The results, which looked at a genome-wide survey of nuclear DNA and Chloroplast DNA analysis, revealed that the purslane on Nishinoshima Island was most closely related to the purslane on the nearby volcanic island of Chichijima.

Though these two species were close, there was some genetic variation. So much so that the team noted that the species on Nishinoshima had experienced what is known as a “founder effect.”

A founder effect occurs when there is a loss of genetic variation as a new and smaller population forms from a larger population.

The Difference Is in the Seeds

According to the study, common purslane seeds are tiny, only about a millimeter long, and rather flat. Because of this, they can easily be spread by wind, waves, and animals. And the researchers found that these seeds would have had a harder time germinating on Nishinoshima. Here, the team started to notice the genetic variance.

In their analysis, the team also noted that this species of purslane experienced genetic drift, which occurs when natural disasters like volcanic eruptions and hurricanes cause genetic changes, not natural selection.

Through their findings, the research team gained a deeper understanding of the phylogenetics of an extinct species and discovered firsthand how some species may survive and regrow after natural disasters like volcanic eruptions.

Read More: How to Stay Safe Before, During, and After a Volcano Eruption

Article Sources

Our writers at Discovermagazine.com use peer-reviewed studies and high-quality sources for our articles, and our editors review for scientific accuracy and editorial standards. Review the sources used below for this article:

• Science Daily. A volcano erased an island’s plants. Their DNA revealed how life starts over
• Plant Systematics and Evolution. Origin of populations of Portulaca oleracea on Nishinoshima, an active volcanic oceanic island