How did genetic parasites overcome natural selection for billions of years?
July 27, 2018 by Lisa Zyga, Phys.org feature
Nearly half of the human genome is composed of genetic parasites—transposons, plasmids, viruses, and other genetic elements that have one thing in common: they don't make any beneficial contributions to their hosts, and can sometimes have harmful effects. Genetic parasites—sometimes called "selfish genes"—originated early in the history of life and today are present in nearly all living organisms.
The discovery that genetic parasites are so ubiquitous and abundant is one of the many surprising findings in the field of genomics, but many questions remain unanswered. One of the most basic questions is simply how genetic parasites have managed to persist for so long, despite the evidence that they are harmful at evolutionary timescales. Typically, natural selection results in deletions of harmful genes, so the main question is, why hasn't natural selection wiped out genetic parasites?
Read more at:
https://phys.org/news/2018-07-genetic-parasites-natural-billions-years.html#jCp
