A research team has created the largest evolutionary tree showing how flowers evolved as part of its adaptation in the continuously changing environment especially during the cold season.
Amy E. Zanne, lead author of the study and an assistant professor of biology in the George Washington University's Columbian College of Arts and Sciences, and her colleagues created a diagram to show the order of the evolution of flowering plants. It also presented how flowering plants have developed certain survival strategies, such as the seasonal shedding of leaves to survive the winter.
The research team was able to identify three evolutionary updates which they believe allowed flowering plants to survive the cold season: shedding of leaves to conserve water, thinning the pathways to lessen air bubbles when the warm season begins, and storing their seeds underground such as the case of tomatoes and tulips.
"Freezing is a challenge for plants. Their living tissues can be damaged. It's like a plant's equivalent to frostbite. Their water-conducting pipes can also be blocked by air bubbles as water freezes and thaws," Zanne said in a statement.
To draft the evolutionary events, the research team prepared two sets of data. The first data include 49,064 plant species which detailed whether each species loses or keeps it leaves before winter or whether it maintains its stem above the ground. They also looked at the exposure to freezing condition of these species. They then combined the first data with the unprecedented dated evolutionary tree with over 32,223 species. The result of the combined data was the diagram showing how the plants survived through environmental adaptation.
"In the near term – say in 10 to 20 years – this kind of information can help us build better models of what's going to happen with vegetation in the future as the climate changes," Peter Reich, co-author of the study, said.
The study was published in the December 22 issue of Nature.
