The resilient moss species known as Takakia, which has thrived for hundreds of millions of years amidst the harsh conditions of the Tibetan Plateau’s cliffs, may be facing a challenge in adapting to climate change, according to a team of researchers who have dedicated nearly a decade to studying this remarkable moss. Takakia is a part of the genus Takakia, consisting of just two species exclusive to the Tibetan Plateau, often referred to as the “roof of the world.”
Professor Dr. Xuedong Li, one of the study’s co-authors, discovered Takakia populations at an elevation exceeding 13,000 feet (4,000 meters) in 2005. Since then, the team has conducted extensive research both on-site and in the laboratory.
Life on the Tibetan Plateau is demanding, with Takakia being buried under snow for eight months annually and exposed to high levels of UV radiation when it emerges from its snowy cover. The moss has been evolving in this region for over 65 million years, dating back to when the plateau was formed due to continental drift, resulting in increasingly extreme living conditions.
The researchers, led by Dr. Ralf Reski from the University of Freiburg and Dr. Yikun He from the Capital Normal University in China, examined how Takakia has developed the ability to survive in such life-threatening conditions. They also documented the significant impact of climate change on the moss’s habitat over a short span of time.
Interestingly, the team found Takakia’s shape preserved in 165 million-year-old fossils from Inner Mongolia, indicating that genetic changes influencing its morphology occurred more than 165 million years ago under vastly different circumstances. Despite its rapidly evolving genome, the moss’s appearance has remained remarkably consistent for over 165 million years, presenting a scientific puzzle for evolutionary biologists.
In sum, Takakia is around 390 million years old and boasts some of the fastest-evolving genes ever observed. It separated from other mosses nearly 390 million years ago, shortly after the emergence of the first land plants. Surprisingly, it possesses the highest number of fast-evolving genes under positive selection.
However, despite its extensive evolutionary history, Takakia faces the threat of climate change. Since 2010, the researchers have documented an annual temperature increase of nearly half a degree Celsius in Takakia’s habitat. Additionally, the glacier near their research sites is rapidly receding, at a rate of around 130 feet (50 meters) per year. As a result, Takakia populations have significantly diminished during the study period, declining by 1.6% annually between 2010 and 2021, a rate faster than that of four common local moss species.
The researchers emphasize the importance of preserving Takakia for studying the evolution of land plants. While the population decline is concerning, it also offers an opportunity for conservation efforts, such as cultivating the moss in a controlled environment.
In the words of Dr. Reski, “Takakia has witnessed the rise and fall of dinosaurs and the arrival of humankind. Now, from this tiny moss, we can gain insights into resilience and extinction.”