Where Did All the Flowers Come From?

Charles Darwin was a lifelong fan of flowers, but was unable to figure out how they evolved. There were fossils of flowering plants going back 66-100 million years, which didn’t help much because flowers evolved much earlier. Recently, however, scientists are turning to DNA analysis of contemporary plants to decode where they came from. They are also finding older fossils than ever before, as far back as 136 million years ago. Paleobotanist James A. Doyle says the fossil record is the only thing that will bring together the many theories of flower evolution.

If you could travel back to 130 million years ago, you might not be impressed with the earliest flowers. “They didn’t look like they were going anywhere,” Dr. Doyle said.

Those early flowers were small and rare, living in the shadows of far more successful nonflowering plants. It took many millions of years for flowers to hit their stride. Around 120 million years ago, a new branch of flowers evolved that came to dominate many forests and explode in diversity. That lineage includes 99 percent of all species of flowering plants on Earth today, ranging from magnolias to dandelions to pumpkins. That explosion in diversity also produced the burst of flower fossils that so puzzled Darwin.

Genetic research is providing answers to how plants can switch on genes that control how different plants parts grow, and to use sexual reproduction to increase genetic diversity. Link