December 17, 2009 – As the Origin of Species celebrates its 150th anniversary, a team of evolutionary biologists from the University of Ottawa put adaptation under the microscope, and once again Darwin comes off looking very good.
In a study in the November 2009 issue of the journal PLoS Biology, the team of researchers that included postdoctoral fellow Sijmen Schoustra and graduate student Danna Gifford, and was led by Rees Kassen, Associate Professor at the Department of Biology, tracked adaptation in a rapidly reproducing fungus.
The goal of this work was to understand how adaptations that allow an organism to out-compete and out-reproduce its kin are built up from occasional mutations in DNA sequences.
“Darwin didn’t know about DNA, and so he couldn’t have understood what raw materials were used by natural selection to craft an adaptation. In other words, he didn’t know how to build an adaptation” said Dr. Kassen.
To see what was happening – step by step – the researchers examined adaptations over the course of 800 generations in two different sized populations made up of more than 100 fungi lineages.
The experimental results revealed that almost all the evolving lines adapted using just a few mutations.
“Darwin was right about natural selection, but it doesn’t need to be as slow as he thought. Adaptation can happen quickly because just a few mutations are involved and the largest benefits tend to happen early on.” he added.
“These results have important implications and provide the first experimental confirmation of predictions about adaptation from modeling,” he said.
The research conclusions demonstrate that it should not be a surprise to see rapid adaptation in nature, whether it be to novel antibiotics in our hospitals or to a rapidly changing climate. The key is for natural populations to adapt quickly enough to avoid being on the wrong end of natural selection.