Sneezes Transmit Viruses and Viruses drop off Useful DNA Code

Virtually all mammals sneeze - people, dogs, cats, mice, seals.  Check it out:  Video Complilation of Sneezing Animals

But it goes beyond just mammals. Birds and reptiles sneeze too (see Iguana Sneeze). Biologists conjecture that the purpose of sneezing is to clear the irritants, mucus and whatnot from our breathing passages and heads. But is this enough reason to explain the widespread occurrence of this bizarre explosive reflex across hundreds of different species?  I don't think so.

There must be something else that sneezing does that is extremely impactful to the success and survival of a species. I suggest that something is sharing and spreading genetic material, not just within a species but across different species.

Science has known for a good while now that viruses can pick up bits of genetic material from one species and then transmit this code to another (reference  reference2). A virus reproduces by getting into our cells, taking over the cells' factories and making copies of itself. Usually the virus moves on, sometimes taking some of our code with it. On rare occasions some of the genetic material the virus carried when it arrived stays within host cell. If that cell happens to be a reproductive system cell then there is the possibility that the gene material dropped off by the virus becomes added to the host's genome - and ultimately to that of the species. 

So how would this benefit a species? Well think about it. The classic Darwinian theory of evolution says that random mutations are the ultimate source of the changes in our genomes. For example, some bits of our genome get damaged -or flipped- by cosmic rays or other radiation. After a long while there can be enough flipped bits such that they are actually meaningful and are of benefit when taken all together. This is a slow slow process.

In contrast, the genetic material spreading and sharing offered by the virus route could drop off sizable chunks of meaningful and potentially useful code in one quick shot. This shot might be a million times more rare than a flipped bit mutation, but its impact could be a billion times bigger. Imagine the impact to a sightless species if it were to receive a chunk of DNA for a complex eye.

So, I'm saying sneezes are around because they spread virus infections which promote faster genetic evolution. Species that didn't sneeze were out-evolved displaced by competing species that did.   

More on sneezes:
Sneeze Appreciation Day
http://en.wikipedia.org/wiki/Sneeze