[Denmark] Unlike animals, who began their evolutionary journey in the water, all terrestrial plants in existence today may have been on land all along, explains a new study. While biologists agree that the evolutionary tree for plants begins with green algae, a team of Danish scientists theorize that the algae from which all plants derive had been lounging on land for hundreds of millions of years rather than floating around in the oceans before drifting inland. A plant’s cell wall is an important adaptation to living on land because it provides support for the plant to withstand the force of gravity, which wouldn’t have the same effect in water.
“We realized that algae have a cell wall that’s similarly complex to terrestrial plant cell walls, which seemed peculiar because ancient algae were supposedly growing in water,” co-author Jesper Harholt of Carlsberg Laboratory said in a statement.
After analyzing the genetic data of a terrestrial species of green algae, the researchers found a number of genes linked to light tolerance and drought tolerance — not exactly concerns of an aquatic organism — that are shared with terrestrial plants. The findings of this study, published in Trends in Plant Science, reimagine a major milestone in the evolutionary trajectory of plant life. Although we tend to focus on animal evolution, specifically our own ancestral lineage, the plant kingdom has a rich natural history all its own.
View original article at: Plants: From algae to trees in 1 billion years