Ant Brains?

Drawings of ant brainsScientists have been studying the brains of ants for many years. The naturalist Auguste Forel dissected and studied them in the early 20th century (see image) and he was not the first. Scientists were especially interested in ants - and their Hymenopteran relatives, bees - because of their remarkable abilities to work together and navigate and because some do different tasks at different stages of life. How could something so small in size carry out such sophisticated behavior?

 

Figure W. Brain of a worker ant.

Figure F. Brain of a queen.

Figure M. Brain of a male.

Collective Intelligence

Today researchers continue to study the brains of ants. The big question has been how do such tiny creatures work together so effectively, and why do they do it?

Charles Darwin studied ants in his garden, and pondered why ant workers cooperated with each other. They didn't fit into his theory of natural selection since they were sterile and not reproducing. Instead they tended the queen, raised the young, maintainied the nest, and in general maintained the colony and helped their nestmates. He proposed that natural selection could work at the level of a whole family rather than of a single individual. Of course Darwin didn't know about genes as a possible explanation, and among ants and some other Hymenoptera the workers are more closely related to their sisters than to any offspring they themselves might have.

Today scientists study collective intelligence, brain miniaturization, and the evolution of the social brain - the concept that creatures living in social groups have developed sophisticated ways of interacting and adapting to their environments. The development of the human brain is thought to be due in large part to the ability of our early ancestors to work together and communicate effectively.

William Morton Wheeler in the early 20th century developed the idea of an ant colony as a single organism rather than a group of individuals. As more was learned about the details of colonial organization, the theory gradually fell out of favor, but recently the concept of a superorganism has become widely accepted.

Want to know more?

  • Holldobler, Bert. 1994. Journey to the ants: A story of scientific exploration. A fsscinating and very accessible introduction to all things Ant.
  • Darwin, Charles. 1859. On the origin of species by means of natural selection. Available online.
  • Wheeler, William Morton. 1910. Ants, their strucutre, development and behavior. Available online.
  • Hamilton, W. (1964). The genetical evolution of social behaviour. Journal of Theoretical Biology 7, pages 1-52.

Ant Brains Today

Color-coded ant brainToday, James Traniello, an Associate in Entomology at the MCZ and Professor of Biology at Boston University, along with colleagues at BU, study the brains of ants. They look particularly at the division of labor in ant colonies and how their brains modulate this behavior.

Muscedere, Mario L. and James F. A. Traniello. 2012. Division of labor in the hyperdiverse ant genus Pheidole is associated with distinct subcaste- and age-related patterns of worker brain organization. PLOS ONE  7 (2), Article Number: e31618.