Paul says:
Rice University study models "Horizontal Gene Transfer," a mechanism for evolution where big chunks of DNA migrate between different species via bacteria. This results in faster and more sudden evolutionary branching than what you get with the more familiar mechanisms of sexual selection or random single-point mutations caused by radiation, copying errors, etc.
Now I feel better about eating those tomatoes with the fish genes in them! (Flavr Savr)
Reader comment:
Roger says: I just wanted to correct the misconception that Horizontal Gene Transfer occurs in plants and animals. Also, Flavr Savr tomatoes haven't been around for about ten years and never had fish genes in them.
I have a blog post here explaining it.
Kevin says:
I just wanted to point out that while previous commenter Roger says horizontal gene transfer doesn't occur in plants and animals, the posted article quotes a "Michael Deem, the John W. Cox Professor in Biochemical and Genetic Engineering" as saying:
"We know that the majority of the DNA in the genomes of some animal and plant species – including humans, mice, wheat and corn – came from HGT insertions"
This seems to be at odds with Roger's position.
Marshall Clark, Technical Director, This Week in Science says:
A quick comment on the post-discussion for the "Horizontal gene transfer explains evolutionary jumps" story. I think Roger may be mistaken when he says horizontal gene transfer does not occur in plants/animals.
In humans, oncoviruses (1) cause tumors through insertion of their viral DNA into human host DNA — a process known as transformation (2). It's been a while since my last university BioChem course, but once the viral DNA has been incorporated into the host's genome I think it's safe to say that you've had a HGT event — one between a virus and a human.
When you consider that viruses and bacteria also routinely pick-up DNA from their hosts (a process called 'natural competence' 3) it becomes clearer how this process might be important evolutionarily.
