It's a common misconception that evolution has a sense of direction, a notion that biology nerds around the world are constantly trying to correct.
There may be more truth to this misconception than we have realized.
It's not as straightforward as a purpose-driven process, but it appears that not all genes are created equal. Not in a flowering roadside weed called thale cress.
Grey Monroe is a plant scientist from the University of California, Davis.
It turns out that the way in which the plant is affected is not random. It's a completely new way of thinking.
There are a number of things that have to go right for a genetic variant to arise. Germline cells must be altered to pass on their genetic material to their offspring.
This could include a change to a single 'letter' in a DNA sequence through UV damage, or the loss of a gene, or the mix-up of an entire chromosomes, when the genetic material is being copied and passed on.
The damage must be prevented from being transferred. This includes repair systems for damaged cells.
The next generation can be passed on if the mutation evades these processes.
Most of the changes in a single letter are neutral, in that they don't change anything in the form or function of the organisms.
Natural selection can affect whether those that cause changes continue through to the next generations.
Evolution was thought to do most of the sorting out between the good and the bad. If a plant or animal is affected by a change in genetics, it is unlikely to last long.
While selection forces can limit which genes are passed on through the generations, the unpredictable nature of the genetic library has made it thought of as an unpredictable dice roll.
Evolutionary theory has been dominated by the idea that the consequences of a single event are different for different people, according to a paper by the team.
Monroe and colleagues used a plant like the thale cress to test the assumption that the random distribution of genes was real. They analyzed the genomes of 400 plant lines, but they were surprised that they were not what they showed.
They found that certain parts of the plant's genome were more prone to change than others.
"These are the most important parts of the genome," says Monroe. The areas that are the most important are the ones that are protected from change.
The effect wasn't due to specific types of DNA, but the region as a whole, if they looked at coding or non-coding parts of the genetic code.
If the discrepancy was caused later by natural selection, their analysis would have detected more unique genes than observed, as they would have been lost later.
The data showed how the DNA is wound around certain genes and how repair mechanisms work. This study supports the idea that DNA repair is targeted to active genes.
Understanding how thale loads the dice when it comes to the evolution and disease of all species could have implications not just for other plants, but for understanding evolution and disease in just about all species.
It gives us a good idea of what's going on because we can predict which genes are more likely to change.
We could use these discoveries to think about how to protect our genes.
Natural selection has skewed the chance of a certain type of genetic change.
The position across a genome is biased to favor an organisms survival even if there is a chance of a different result.
Nature published their research.
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