Our Genome Has Adopted Virus Genes Critical to Our Survival
Mammals Made By Viruses by Carl Zimmer
The big picture thats now emerging is quite amazing. Viruses have rained down on mammals, and on at least six occasions, theyve gotten snagged in their hosts and started carrying out the same function: building placentas.
Some mammals that scientists have yet to investigate, such as pigs and horses, dont have the open layer of cells in their placenta like we do. Scientists have come up with all sorts of explanations for why that may be, mainly by looking for differences in the biology of each kind of mammals. But the answer may be simpler: the ancestors of pigs and horses might never have gotten sick with the right virus.
More amazing facts from science. This stuff is so interesting. Carl Zimmer is a fantastic science writer and he has written several great science books.