Plant speciation caught in the act
17 March 2011
The results from a new study by SBCS biologist Richard Buggs has shed light on how evolution works, and could help to improve crop plants. Dr Buggs studied a new plant species from the Daisy family, Tragopogon miscellus, which only appeared in the United States around 80 years ago. This new species was born when two related species, both introduced from Europe, mated to produce a hybrid offspring.
Although these two species had mated before in Europe, the resulting hybrids were never successful. However, in America something new happened. The number of chromosomes in the new hybrid spontaneously doubled, and at once it became larger than its parents, it was able to quickly spread.
Dr Buggs and colleagues from Florida – where the study was carried out - recreated this event in the lab. Newly published in the journal Current Biology, the team found that the first generations of new hybrids underwent a relaxation in the control of which of their genes are expressed. Because this relaxation is not seen in the wild plants, it suggests that within 80 years of evolution the plants are able to fix their gene expression to adapt to new environments. In other words, the plants underwent a genetic reboot, and now only use some of their genes depending on where they live.
Crossing different plant species to produce hybrids is a process used in farming to produce greater yields and stronger plants. Studying how this works in nature can give us new ideas to apply to agriculture.
The work was carried out at the University of Florida and Iowa State University and involved scientists from Queen Mary, University of London, Massey University in New Zealand, and Shanxi Normal University in China.