Evolution of the First Flowers

A new study led by Florida Museum of Natural History researchers are trying to find the answers to questions such as: What did the first flowers look like? How did they evolve from non-flowering plants? It provides insight into how the first flowering plants evolved from genetic programs found in gymnosperms and developed into the flowering plants that we see today. The goal of the research is to understand the set of genetic switches that produced the first flower.

Charles Darwin had said that the emergence of flowering plants 130 million years ago was a mystery. The flower is one of they key innovations of evolution, since it caused a massive burst of evolution that has resulted in as many as 400,000 angiosperm species. Before flowering plants existed, the seed-bearing plant world was filled by gymnosperms, which have cone-like structures instead of flowers. Examples of these are pine trees, sago palms, and ginkgos. Gymnosperms appeared in the fossil record about 360 million years ago.

The study compares the genetic structure of two very different flowering plants to see if there existed differences in the set of circuits that create each species’ flower. Researchers examined the genetic circuitry of Arabidopsis thaliana, and Persea Americana. The flower of Persea is a genetic fossil, still carrying genetic instructions that would have allowed for the transformation of cones into flowers.

Advanced angiosperms have: female organs, male organs, petals and sepals. Basal angiosperms have: carpels, stamens and tepals. The researchers expected each type of organ found in Persea’s flowers would have a unique set of genetic instructions, but they found that the genetic instructions showed significant overlap among the 3 organ types.

Researchers don’t know which gymnosperms gave rise to flowering plants but previous research suggests some genetic program in the gymnosperms was modified to make the first flower. A pine tree produces pinecones that are either male or female but flowers contain both male and female parts.

This study highlights the importance of studying primitive flowering plants to gain insight into the early history of the flower.

This study is an example of discovery-based science because there wasn't a hypothesis based preceding the study, the researchers made their conclusions based on the results that they found. This research has an importance that if they find exactly how the flowering plants started they can figure out how many other species evolved from this first flower.

Bibliography:

Bill Kanapaux. “Evolution of the First Flowers.” Natural History Magazine. 8 February 2012. National Geographic. 8 February 2012. http://naturalhistorymag.com/partner/evolution-of-the-first-flowers?page=2