From time to time, you will see a mushroom in your yard and not really think about it that much besides wondering when it got there. It would be small, and you could probably smash it with your foot, but that does not compare to the other types of fungi that exist on the planet. For instance, the Armillaria ostoyae is the largest, and most deadly fungus on the planet. According to the article, this fungus creates rhizomorphs, which are responsible for taking in nutrients from dead organic matter such as from dead plants and animals. After analyzing the genomes and rhizomorphs of this species of fungi as well as comparing it with other species called fruiting bodies, it was determined that the genomes of the Armillaria ostoyae were expanded because certain sections were copied multiple times, which led to different changes in the behavior of the fungi. For example, the Armillaria ostoyae fungi had more proteins that were responsible for ingesting cells and parts of plants. The differencces in the genome was also responsible for making the Armillaria ostoyae undetectable, because it was able to ingest nutrients around trees that were found in the soil around them that would normally "alert" the tree that the fungi was nearby, and this would allow for the Armillaria ostoyae to be undetected, allowing for it to begin to take nutrients from the tree, and eventually kill it. It was also found that the fungi's rhizomorphs had photoreceptors and pheromeres that are used to detect the plants and animals it will consume, unlike the fruiting bodies. This shows how deadly this fungi can be, as it has a genome that allows for it to completely wipe out entire forests. However, what was also found was that despite this difference between the Armillaria ostoyae and the fruiting bodies, they actually have most of the same genes, which suggests that the Armillaria ostoyae might have had a mutation millions of years ago that caused for this behavior to occur.
I find for this article to be really interesting. I think it is fascinating that the genomes of organisms can change over time as they adapt to their environments. I think that this is very important in a changing environment, because without the concept of "survival of the fittest," then there would probably be no life on earth or very little. Populations of different organisms and plants would be completely wiped out because of predators or other causes. However, genomes change not only for survival in that way, but they can also change in order to benefit themselves as well as the environment. The Armillaria ostoyae is not just seen as a deadly forest pathogen, it is actually helping out forests by promoting healthy growth and allowing for the healthy trees to thrive more. So in a way, this "deadly forest pathogen" is actually the reason for why forests are able to grow more, and I think that it's really awesome because it was caused by this change in the genome of a the Armillaria ostoyae.