Scientists Measure How Quickly Plant Genes Mutate 67
eldavojohn writes "A recent study puts observed numbers on genome mutations in plants. This kind of research is becoming more popular in understanding evolution. The research 'followed all genetic changes in five lines of the mustard relative Arabidopsis thaliana that occurred during 30 generations. In the genome of the final generation they then searched for differences to the genome of the original ancestor.' A single generation has about a one in 140 million chance of mutating any letter of the genome (which has about 120 million base pairs). Sound like bad odds? From the article, 'if one starts to consider that they occur in the genomes of every member of a species, it becomes clear how fluid the genome is: In a collection of only 60 million Arabidopsis plants, each letter in the genome is changed, on average, once. For an organism that produces thousands of seeds in each generation, 60 million is not such a big number at all.' The academic paper is available in Science, though seeing more than the abstract requires a subscription."
Re:evolution ? (Score:5, Informative)
Scientists are always trying to disprove. 'proving' a new theory is much harder than disproving the most widely adopted theories. see 'falsifiability' http://en.wikipedia.org/wiki/Falsifiability [wikipedia.org]
Great piece of work! (Score:5, Informative)
Our current understanding of how dynamic a genome is, the types of changes that occur, and the factors that limit these changes is very limited. Much of this is because getting a genome of an organism can be expensive and laborious, depending on the size of the genome (RNA virus 15,000 nt, DNA virus: 150,000 nt, bacteria: 5,000,000 nt, yeast: 20,000,000 nt, multicellular organisms: 100,000,000-10,000,000,000). Since our understanding of how genomes evolve depend on getting genomes sequenced that are appropriately related to one another (e.g. populations of organisms versus diversity of organisms), we can only get answers for those genomes we currently have (current ~8000 for all viruses, bacteria, archaea, and eukaryotes). Fortunately, there is currently a major technological revolution happening in biology: generating DNA sequences fast and cheap. For example, the first human genome was approx a 10 year project and cost ~$1,000,000,000. Now, the record for a human genome takes less than a week and costs ~$15,000.
This project is a major milestone as the authors sequenced 6 plant genomes (a mustard known as Arabidopsis thaliana) that are related to one another by 30 generations. Because of the close evolutionary relationships of these organisms, the authors can characterize the types of genomic change happening over very short time periods.
The emerging picture is that genomes, the fundamental genetic blueprint for a lineage of organisms, are much more dynamic than we had previously thought.
Re:A question about Lenski's work. (Score:2, Informative)
Absolutely stunning piece of work:
http://www.nature.com/nature/journal/v461/n7268/full/nature08480.html [nature.com]