Could our DNA have evolved from simple viruses?

In this blog, I discuss the evolution of complex organisms from more primitive ancestors. When I do this, I go way, way, way back in time.. before mammals, dinosaurs, fish, simple sponges, one celled protozoa, and even before the first bacterium! I start with the first replicons. A simple replicon is a single piece of circular DNA like a virus, a plasmid, or a transposon (jumping gene). In today’s world, replicons cannot exist outside of a cell because they lack the machinery required for self replication, i.e. the proteins required for DNA synthesis. However, they may have been able to exist and evolve as parasites within primitive cellular hosts whose genome was composed of RNA that functioned both as  hereditary material and as enzymes. The stability of these circular DNA structures may have provided an evolutionary advantage to these primitive hosts, paving the way for the first phase in a process I call hierarchical endosymbiosis. This phenomenon may have allowed life to rapidly evolve through a series of geometric integrations of DNA cassettes in roughly the following sequence of events: virus, bacterium, simple eukaryote, and complex eukaryote. All of these integration events may also be occurring simultaneously.

I present models to explain how these integration events may have occurred at the molecular level, beginning with simple replicons and ending with complex eukaryotic chromosomes. There are also models to explain how transcription is enabled via differentiation and how introns are spliced out of the final mRNA product. These models can be viewed directly at this blog by clicking here or going to the original website that describes them and other processes in considerably more detail.

Advertisements

About frankabernathy

I am a retired cell biologist and alumnus of Ohio State University. I became interested in chromosomes as far back as the 1960's when I wrote a term paper on the effects of radiomimetic drugs on chromosomes. I was fascinated at how they could break apart and reform new structures so easily. I became further involved in the early 1970's after taking a cytogenetics course at the University of Arkansas. I took that knowledge with me to Ohio State in 1980 where I eventually worked on my research and completed my Ph.D. dissertation, "Studies on Eukaryotic DNA Superstructure". My studies and later research suggested that the DNA within the eukaryotic chromosome is not the simple, linear molecular thread so widely suggested in all the classic textbooks published today. Instead, it may be the culmination of a geologically rapid set of endosymbiotic events where microorganisms plug into each other to create something greater than themselves. Feel free to contact me at fabernathy@sbcglobal.net.
This entry was posted in evolution and tagged , , , , , , , , , , , , , , , , , . Bookmark the permalink.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s