New hypotheses on the material nature of horizontally mobile genes.
The evolutionary history of organisms is often assumed to be recorded in the structure of important molecules, such as DNA sequences. Whereas the structure of these molecules does sometimes affirm other evidence of ancestry, like fossil records, it sometimes does not. Horizontal gene transfer can distort perceptions of ancestry. Determining the impact of horizontal gene transfer on evolution has been limited by the crude tools available to detect it. Physical and genetic vectors are now known to conduct genes between organisms, even between biological kingdoms of organisms. The effects are being noticed in important molecules preserved in the genomes of organisms. This article will review the systematic bias in using molecular morphology, like DNA sequences, to infer ancestry and how this bias is the unavoidable result of the way that experimental genetics itself evolved. We present the novel hypothesis that genes usually called epigenes, like methylation patterns and prions, are infectiously transferred, sometimes using DNA as a vector, but not as a gene.