Charting Ever-changing Genomes
Instead of resembling immutable proprietary software, a species'
genetic information is more like open-source code that is constantly tweaked and
optimized to meet the users’ specific needs. So, which parts of the code have
withstood the test of time, and which parts have undergone rapid evolutionary
change? Joseph Ecker and his collaborators developed a simple method to comb
whole genomes for all the software fixes and security patches accumulated over time.
In a first trial run, the scientists recently catalogued the genetic variations in 20
strains of the mustard weed Arabidopsis thaliana that had been collected from the
wild all over the world. As a general rule, genes that don’t change over time perform
important housekeeping functions, while genes that vary widely are likely to mediate
interactions with the environment. Identifying the genes that can help plants
withstand challenging conditions such as heat, drought, high acidity, or salinity will
give plant geneticists the tools to create tougher breeds that can easily adjust to new
ecological niches arising due to climate change.
