|Influenza virus illustration from CDC.gov|
Research on mice reveals that endogenous retroviruses are important in their brain development. Good observational science is once again being fouled up with evolutionary speculations about how the stuff was probably a part of our evolution. Declaring "evolution" by offering guesses without evidence pays well; I'm in the wrong line of work!
About 8–10% of human DNA, as well as the DNA of animals like mice, consists of scattered DNA sequences matching those of retroviruses. These sequences are called endogenous retroviruses (ERVs) because they are actually a part of the healthy host cell’s DNA. (Exogenous retroviruses—like HIV that causes AIDS—come from outside a cell and infect it.) How ERVs came to be part of our DNA and what they are doing there have been the subjects of much speculation and research. Scientists have known for some time that placental formation depends on ERVs. Evolutionists credit such viruses with making mammalian evolution possible. Now scientists have shown that ERVs play a crucial role in the development of the mouse brain.This article is nothing to sneeze at. You can read the rest by clicking on "Endogenous Retroviruses: Key to Mammalian Brain Development?" On a related note, you may want to check out "Viruses — Architects of the Brain?"