Aggression"You Buzzin' at Me? You Buzzin' at ME?"
Life is a constant struggle: for access to food, for access to mates, for survival itself. These constant contests between competing individuals, whether fruit flies, humans, or aardvarks, require some level of aggression. While aggression is a necessary and important trait to possess, like many things in life it can lead to very negative ends when not controlled. The word itself connotes that negativity: what's the difference between someone who is "competitive" and someone who is "aggressive"?
It shouldn't be surprising to learn that there are genes which affect the aggression of animals. While there are certainly very significant environmental effects (how an animal is raised), we're all familiar with the idea that certain breeds of dog, for example, are much more aggressive than others.
To study such genes, researchers at the Neurosciences Institute in San Diego have bred fruit flies to be more aggressive: in only 10 generations of selective breeding, they saw significant increases in aggressive behavior (Read the full article in Nature).
The Drosophila gene fruitless (abbreviated fru) is central to both sex determination and male courtship behavior in fruit flies. In addition, recent research has shown that it is also important in determining levels of aggression in flies and how that aggression is displayed: given the right genetic tweaking, researchers have created male flies that fight like female flies, and vice versa.
Our understanding of the role of genetics in aggression is still fairly limited, because the study of the genetics of behavior is a relatively young field, but the use of model organisms such as Drosophila has begun to give us some insights into the process. Learning more about how "aggression" genes (and all the others) are controlled — when and where different versions are active, what other genes affect their expression — is one of the major goals of the modENCODE project, one which will improve our understanding of the complexities of the genetic basis of behavior. And with better understanding, hopefully we will be able to better control our own aggressive tendencies as well as those of animals we live with, and thereby make the world a safer place for all of us.
- What are some good points about aggression? Bad points? What would a world of people who were not aggressive at all be like? What about a world where everyone was highly aggressive all the time?
- Do you think it's a good idea for researchers to study the genetics of aggressive behavior? What reasons can you think of that would argue in favor of such research? Against?
- Lab website for Prof. Edward Kravitz ("Fruit Fly Fight Club")
- Drosophila fighting (0:46)
- Drosophila fighting (3:54)