December 6, 2012
Solving A Mystery: Where Did Flowers Come From?
Michael Harper for redOrbit.com — Your Universe Online
Beautiful flowers and flowering plants are quite commonplace in our world, a lovely addition to the natural landscape of things. Flowers have even helped shape our history and our art for thousands of years, acting as a symbol of beauty, love and passion.
Though we simply acknowledge flowers as familiar and standard, there remains one mystery about these colorful and often vibrant angiosperms: Where did they originate?
It´s a problem nineteenth-century naturalist Charles Darwin dubbed the “Abominable Mystery.” For many years scientists were not able to pinpoint exactly where in the timeline of Earth these flowers arrived, simply that they were suddenly here.
This week, Indiana University paleobotanist David L. Dilcher and his European colleagues have published a paper online which presents a scenario for how these flowering plants may have developed, colonized and became so prevalent all those millions of years ago.
Dilcher, working with colleagues from Berlin and France, has suggested that many of these angiosperms (flowering plants) may have evolved in aquatic environments over 45 million years ago in the middle Cretaceous Period.
To complete this study, Dilcher and his colleagues examined previous and extensive fossil data from Europe. This data helped the team connect the evolution of these flowering plants with the changes in the surrounding environments. The data gathered in Europe is consistent with data found in the US, says Dilcher, who has been studying flowering plants for decades. Some of his work has suggested that these flowering plants have also resided in aquatic or near-aquatic environments.
"This attention to the total picture of plant groups and the paleo-environment begins to form a pattern," said Dilcher in a prepared statement. "We're able to turn the pages of time with a little more precision."
According to this new research, it was these aquatic environments which helped the spread of these flowering plants. As there are flowering plants all over and not just near aquatic environments, Dilcher and his team have discovered that these plants must have migrated in 3 phases.
To begin, Dilcher and his colleagues have found that these flowering plants began at freshwater, lake-related wetlands somewhere between 130 and 150 million years ago. These plants then moved to understory floodplains between 125 and 100 million years ago. Finally, flowering plants began to appear in natural levees and swamps between 100 and 84 million years ago.
Previous research into the Abominable Mystery has focused on collecting fossils of these flowers and looking for similarities between them and today´s modern flowers.
Dilcher and his team, however, took a different tack, opting to analyze the anatomy and morphology of the biology of these plants to determine their origins.
He also mentioned that the relationship between these flowering plants and insects also gave the angiosperms an evolutionary advantage. As these insects helped to cross pollinate the plants, they also helped to speed along the spread of new genetic material. These plants then evolved to draw insects in with more brightly colored petals and stronger fragrances. The flowers were then able to pollinate with one another while the insects were able to sustain themselves with nectar from the flowers.