Figure 2. Evolutionary layers of the X and Y chromosomes. (a) Comparative mapping of genes from the human X in marsupial mammals detected an ancient region conserved on the X in all mammals and denoted XCR, as well as a recently added region denoted XAR that is autosomal in marsupials.
Poliovirus, the causative agent of poliomyelitis (commonly known as polio), is a human enterovirus and member of the family of Picornaviridae. Poliovirus is composed of an RNA genome and a protein capsid. The genome is a single-stranded positive-sense RNA genome that is about 7500 nucleotides long.
It regurgitates a claim that SV40 that contaminated some early batches of the polio vaccine in the late 1950s were the cause of the âcancer epidemic.â Other variants of this claim are that the polio vaccine was responsible for creating AIDS. The first is a distortion and exaggeration; the second is even worse.