Studying evolution is like playing a detective game, where the scientists try to collect evidence and put pieces together to reveal what happened millions of years ago.
In the world of mosses, a group of tiny plants that bear no flower, one such mystery surrounds Meteorium, a genus that has puzzled bryologists for decades.
Meteorium is a pantropical group of mosses, meaning it grows across tropical regions worldwide (Huttunen & Quandt, 2007). Many of its species live as epiphytes, growing on other plants rather than in soil. Alongside a closely related sister, the genus Papillaria, it forms a major branch within the moss family Meteoriaceae. While bryologists have successfully define the genus Papillaria (de Oliveira et al. 2020), Meteorium has remained an evolutionary enigma.
At first glance, defining which species belongs to the genus Meteorium is not the biggest problem. The real challenge lies within: how are the Meteorium species related to one another? Where did they originate? And how did they spread across continents?
To solve this puzzle, we stepped into the role of evolutionary detectives. We combined traditional morphological traits with modern molecular tools, also known as DNA. By pulling information from 100 morphological characters and approximately 2700 nucleotides from four different gene regions, we were able to compare different Meteorium species at a genetic level, uncovering the relationships invisible to the naked eye.
This dual approach paid off. The genetic data revealed that all American species of Meteorium belong to a single evolutionary branch, confirming they share a common ancestor. Meanwhile, the Asian species showed greater diversity, with fourteen distinct species identified. However, perhaps the most intriguing clue was geographic. The evidence points to a continental Asian, in regions such as China, India, Japan, Nepal, and Bhutan. From there, the genus appears to have expanded south and diversifying across the Indochina, Malesia, Papua New Guinea, and even reaching Australia.
These findings do more than tidy up a taxonomic mess, they tell a story. A story of migration, adaptation, and diversification over millions of years. They show how a group of humble mosses spread across the tropics, evolving into the variety we see today.
In the end, phylogenetics—the science of reconstructing evolutionary relationships—acts like a magnifying glass for life’s history. By combining physical clues with genetic evidence, scientists can reconstruct ancient lineages and solve mysteries that once seemed unsolvable.
In the case of Meteorium, the evolutionary detective work is finally bringing light to its history.
Thien-Tam Luong
I am a doctoral researcher at the TUR Herbarium, focusing on the taxonomy and systematics of the tropical moss. I am interested in solving taxonomic puzzles using molecular phylogenetic methods without forgetting morphological traits.
References:
Huttunen, S., & Quandt, D. (2007). Phylogenetic relationships within the moss family meteoriaceae in the light of different datasets, alignment and analysis methods. In AE. Newton, & RS. Tangney (Eds.), Pleurocarpous Mosses: Systematics and Evolution (pp. 145-162). Taylor & Francis/CRC Press.
de Oliveira, J. R. P. M., Quandt, D., Newton, A. E., Pôrto, K. C., Luong, T.-T., & Huttunen, S. (2020). Systematic Revision of Papillaria (Meteoriaceae, Bryophyta). Systematic Botany, 45(3), 411–438
