Horizontal Evolution

In this article, a team of scientists outline a new theory of horizontal evolution. And it makes us all ask ourselves, what the hell is that? Well the traditional view of genetic evolution through natural selection, which these scientists are calling vertical evolution, falls under the Darwinian view of "survival of the fittest." Essentially, everyone inherits their genes from their parents, and then pass them on to their kids, and whatever genes in whatever organisms help that species survive best will continue to proliferate the gene pool (and vice versa with genes that aren't fit for survival). But these scientists have found evidence of horizontal gene transfer, meaning the inheritance of genes from one organism to another. But they can explain this much better than I can . . .

In the past few years, a host of genome studies have demonstrated that DNA flows readily between the chromosomes of microbes and the external world. Typically around 10 per cent of the genes in many bacterial genomes seem to have been acquired from other organisms in this way, though the proportion can be several times that. So an individual microbe may have access to the genes found in the entire microbial population around it, including those of other microbe species. "It's natural to wonder if the very concept of an organism in isolation is still valid at this level," says Goldenfeld.

No, this does not mean that by making out with someone you can inherit their genes. In fact, it is still very unlikely that organisms as complex as mammals exchange genetic information with each other. But, considering the prevalence of this genetic transfer between small microbes that scientists have discovered, it is not unlikely that much of the early evolution of single-celled organisms billions of years ago was due to horizontal evolution. And now many scientists are wondering if and how small microbes can influence our genetic codes today - could a virus be considered horizontal evolution? A virus is a small microbe, it enters your blood stream, and it takes over host cells to do its bidding (i.e. implants genetic code within the cell containing information to create more of itself and often also proteins that lead to the observable biological effects of the virus). If you think of your cells as other microbes, how different is this process from that described by scientists in the study?

And at what point do you draw the line between a virus and horizontal evolution? If a virus changes you biologically, and your genes are the blueprints for your biology, is the dividing line just a frame of reference? Obviously you're entire genetic code isn't changing, but what about the infected cells? Which makes us go back to the kssing thing, if you get mono from someone, is that horizontal evolution? Is changing your body temperature, decreasing your energy, and inflaming your throat signs of genetic change in many of your cells? If you say "no, you can take medicine and get healthy again," who's to say the medicine isn't just another microbe exchanging genes with those infected cells?

Please don't take me out of context in thinking that I believe we're all constantly evolving with every bacterium we come in contact with, but at the same time don't discount the possibility that we sometimes might. And remember that if this kind of thing is happening, it's likely not with complicated and specialized genes for individual organisms. You can't get a virus that makes you grow more arms, or at least I highly doubt it. The kinds of genetic information exchanged could only be the kinds of information that the microbes contain to begin with - and I doubt there's a virus out there with anything more drastic than the ability to replicate and produce some simple proteins.