During this process, the bacteria "choose" whether or not to enter a state called "competence," in which bacteria change their membranes to more easily absorb substances from their neighboring, dying cells. As a result, they recover more quickly when the stress is gone. According to Prof. Ben-Jacob, it's a difficult choice -- in fact, a gamble. The decision to go into a state of competence only pays off if most of the cells decide to sporulate.
Indeed, observations show that only about 10% of cells decide to go into competence. So why don't all bacteria attempt to save themselves? Bacteria don't hide their intentions from their peers in the colony, he explains -- they don't lie or prevaricate, but communicate their intentions by sending chemical messages among themselves. Individual bacteria weigh their decisions carefully, taking into account the stress they are facing, the situation of their peers, the statistics of how many cells are sporulating and how many are choosing competence.
Facing tough choices
There are many times in life when humans face similar decisions, says Prof. Ben-Jacob. One example is choosing whether or not to be inoculated during flu season. Do you take the risk of the side effects and get inoculated, or do you trust that most of the people around you will get the vaccine and risk possible illness, sparing you both the disease and the side effects from the vaccine? How do politicians make decisions on key issues, such as national debt, that can harm and benefit society?
There will always be "noise" surrounding decision making, says Prof. Ben-Jacob, but like bacteria, we can use this information to make an action plan. Though bacteria react individually, he notes, there is co-ordination between the cells. It's important to make choices that both b
|Contact: George Hunka|
American Friends of Tel Aviv University