Asside from just the general expansion of knowledge and understanding of how things work, is there any practical application of evolution, that wouldn't be available if we didn't study and theorise about it? I ask because I have a friend who says it is a waste of time and just anoys people.

Well Tom, there can be practical applications to evolution. I know of one study that used the traits of mutation and descent in applied engineering. A company wanted to design a better nozzle for a pipe outlet and took a normal model and had it cast 10 times is a plastic that was then deliberately deformed as it was made.

They then took these modified nozzles to see which was the most efficient and made more copies (again with deformities). After a few generations of this they had created a nozzle about three times (if I remember correctly) more efficient than the original. In a classic copy of evolution, the best adapted (here most efficient) were selected for, and the lest adapted were removed. Errors in repliction (the casting process) occasionally made better nozzels and these were then used for the next moulds (had the most descendants).

Of course, we also use evolutionary theory for all kinds of medical applictions - you need a new 'flu injection every year (as do your pets for various other viruses) as these are constantly evolving and we need to beat them. If we are ever to halt diseases like AIDS, malaria, and many cancers we have to understand how and why things evolve.

Hi Tom,

Just to add to what David said, as well as the massively important medical applications, evolutionary theory is also being used for wildlife and conservation issues. Off the top of my head I can think of many cases where evolutionary biologists are working on improving management of fisheries and animal species that are hunted for food (or trophies). Also there is a lot of evolutionary research into the way in which organisms are (or aren't) adapting to climate change, which is obviously a hot topic and very important when thinking about practical conservation measures.