No, not jumping jeans. We’re talking DNA not dancing music. Horizontal DNA transfer is a booming field of evolutionary science which is hot on the trail of explaining large leaps in evolution. H-DNA transfer can occur between species and, in fact, between the plant and animal kingdom. It also can occur between viruses and other species as well as between bacteria and higher forms of life. We’re not just talking infection but gene/DNA transfer into the other species.
Take the lowly sweet potato. Sweet potatoes from all over the world naturally contain genes from the bacterium Agrobacterium. Researchers from UGent and the International Potato Institute (CIP) published this discovery on the website of PNAS (Proceedings of the National Academy of Sciences of the United States of America). Interestingly, the sweet potato is one of the most important food crops for human consumption in the world. Because of the presence of this “foreign” DNA, sweet potato can be seen as a “natural GMO.”But, it was ‘modified’ by bacteria, not lab scientists.
Photo courtesy of Science Daily
This gene transfer is most common in a group of organisms which scientists have labeled prokaryotes- organisms which do not have a defined nucleus to envelop its DNA materials. An article in Aeon by Ferris Jebr states:
‘What scientists have seen is just a little tip of an immense iceberg,’ says Antonio Teixeira, a biologist at the University of Brasilia. W Ford Doolittle, a biochemist at Dalhousie University in Nova Scotia, agrees: horizontal gene transfer, he wrote recently ‘is far more pervasive and more radical in its consequences than we could have guessed just a decade ago’. Researchers have now discovered so many examples of gene transfer between species and kingdoms of life – with many more surely to come – that they have to adjust their understanding of how evolution works. Standard evolutionary theory does not account for the possibility of complex organisms suddenly acquiring genes from other species, let alone how those foreign genes might change a creature for better or worse. Think of it this way: if the genomes of living species are flowers on different branches of the great evolutionary tree of life, horizontal gene transfer is a subversive wind whipping pollen from one part of the tree to another.
What about us? Well, if we put on our Thinking Caps, we might be able to imagine that we are big clumps of composite DNA which got transferred into us from non-human sources along our evolutionary trail. In other words, we may be the at the top of evolutionary heap, having acquired bits and pieces of ‘stuff’ from creatures lower in the pile. Not exactly what Genesis says especially the part about being made in the image of God.
For an interesting read about how the fern stole the DNA from the hornwort visit http://aeon.co/magazine/science/how-horizontal-gene-transfer-changes-evolutionary-theory/