Influenza: Evolution in a Petridish

Sami Snyder - June 24th, 2009 in Feature 0 votes Vote Up! Vote Down!

If you’ve ever gone to your local clinic or doctor’s office to get your annual flu shot, you know there is either a line or a few days wait before you can get poked by an ancient nurse with shaky hands and bad eyesight. The trouble of going there, waiting in an uncomfortable chair, and smelling her musty perfume every year tends to get old before your first time. You start to wonder, “Why do I have to come in every year, while other vaccines are guaranteed for multiple years, sometimes even a decade or more?” It must be the pharmaceutical companies wanting all of your hard earned cash or sucking your insurance dry. Wrong.

The influenza viruses are known for their ability to mutate. Any virus is highly capable of doing this at a fast rate, but the flu is infamous for its high rate of mutation, meaning your shot will be pretty much useless ten months from the day you got it. This is due to a virus’ ability to cut, copy, and paste their host’s and their own DNA practically anyway and anywhere they want it. They can swap genes with their host or even other viruses vacationing in the same organism. This means your immunities for last year’s virus is now out of style, and won’t protect you against the new strain. If you are a rich masochist, this is wonderful news. However, if you are like many others who fear pain and/or needles, getting the flu doesn’t sound like such a bad thing after all.

How is this related to evolution? It is the fundamentals of the process. Evolution occurs when one or more mutations change an organism. Over time, these mutations allow the animal to adapt. Some mutations are useful to finches in gathering certain types of food; other mutations help viruses spread faster. The influenza viruses are constantly evolving. Every year the common strain will mutate, leaving the previous vaccine moot and ineffective. Although it has a mutation that can drastically effect the way it works, it is still an influenza virus. This is known as microevolution. A mutation will change the organism’s appearance or function, but it will still be of the same species. Many skeptics of evolution typically have a hard time believing in giant leaps in the process, also known as macro evolution. What many fail to understand is that macroevolution is simply many micro evolutions over time in a population to evolve into a new species. In animals, the process of mutation takes much longer than a virus. It can take hundreds or thousands of years before enough micro evolutions occur and separate a group into its own species.

Viruses are constantly mutating and going through tiny microevolutions, but people hardly ever think of it that way. They just think their vaccine wears off and needs renewed. Remember the next time you go to the doctor to get your shot that it’s well worth the old lady musk and “bee sting” injection, because with every new strain your body has a lower chance of keeping the virus from running its full course.