THE AMOEBOID BRAIN

If you lived on the surface of a rock in a pond and were only about 5 micrometers thick (a micron is 1/1000th of a millimeter), your life would be very different. You couldn't really fall down, since down is an extremely tiny distance. Up wouldn't make much sense either because it is relative to down. There would, of course, be forward and back, if you had some way to tell which was which. If you were quite round it might be more difficult. If you had an elongated shape I suppose you could have a right and left, but if you are more or less amorphous, those two concepts would be just a hazy notion of sideways to some degree or another.

Thus is the life of most amoeba, I suppose. If you find this thought intriguing you might enjoy reading the classic short book by Edwin A. Abbott called "Flatland: a romance of many dimensions". He explores life of a Mr. A. Square in a land of two dimensions. But A. Square's life must be very much like an amoeba's.

Yet amoeba can do some amazing things. If you place amoeba in a container and place a food supply in any direction from them, they will all eventually turn and begin to move in that direction. If you place toxic chemicals in their environment, they will move away from the source of irritation. If they like the dark, they can find the deepest shadows.

This is even more amazing. Amoebas grow by simple fusion, dividing in two. If you take a population of any given species of amoeba from some pond and allow them to develop large numbers, and then mix them with another population of the same species but from a different pond, they will live happily together. However, if you then cut off their food supply; they will eventually eat members of the other population, but will starve to death before eating members of their own type. They can recognize their own progeny. I sometimes look at my grand kids and can't even do that.

The amoeboid world is pretty slow as well. All amoebas live in aquatic environments. Life in the fast lane for an amoeba might be a fish swimming by and creating a current. They don't float free in the water normally, but are restricted to their two dimensional world, to which they cling tenaciously with their ever changing arms called pseudopodia. But they know all of this, and if they should be suspended in water by the fishy currents, they cease trying to move until they are safely settled back onto a nice two-dimensional plane.

Living in water, you might expect that they aren't very fast also. One of the faster amoebas around can sprint at speeds of 0.5 to 3.0 micrometers per second. I think that makes their fastest time for a "one millimeter dash" around 5 minutes. However, many amoebas are slower than that. Still they seem to get where they want to go.

You might wonder why it is important to know anything about amoeba. There are actually a lot of reasons, some involving disease, other involving their role in nature and the food chain.

But the reason that I find most interesting is that they seem to be able to do a lot of the things I can do, but with only a single cell. True, they can't do algebra, but then I'm not very good at that either. They don't talk, or at least in an audible language. They do communicate very complicated information chemically. In fact, amoeba can talk to one another. By secreting chemicals, they can tell other amoeba what they are doing and what they want the other amoeba to do. This is exactly what the cells of your brain do: secrete chemicals that communicate with other brain cells. That is exactly what the brain is composed of cells speaking a chemical language to one another.

So do amoebas think? I guess that all depends on what thinking is, and thinking may just not be what you think it is. And amoeba may prove to be more interesting than you think.

THE CONSEQUENCES OF GETTING YOUR WIRES CROSSED

Imagine you have built a small robot car that is powered by two electric motors, one to each rear wheel. If the right motor revolves more rapidly than the left motor, the car will veer to the left. If the left motor is faster than the right the car will turn right.

Imagine this car has two light sensors on the front of the car, set several inches apart. These light sensors are connected to the motors of the car and control the power to the electric motors such that the more light that hits the sensor the faster the motor turns. The right sensor is connected to the right motor, and the left sensor is connected to the left motor.

Imagine we have placed this car in a darkened gymnasium. It will not move because there is no light. But we have placed a remote controlled light bulb in the center of the floor. When we turn the light on the car will begin to move. However, because of the distance between the two sensors, the amount of light striking the right sensor will be greater than the amount of light striking the left sensor. This will cause the right motor to revolve faster and the car will veer away from the light until it is exactly facing away from the light so that the amount of light to each sensor is equal. It will also go as far away from the light as possible until the sensors are no longer stimulated.

Imagine you are observing this with a friend from the rafters of the gym. Your friend might say something like, “Wow, that thing really doesn’t like the light. It runs and hides. How did you make it do that?” Of course, it doesn’t “like” or “dislike” anything. It’s a robot. It just appears to be a little like a cockroach.

Stay with me here. This is actually very applicable to you.

Imagine you make one small change in your robot; you connect the right sensor to the left motor and the left sensor to the right motor. Then you turn the light off, reposition your robot in the gym, and you resume your perch in the rafters.

When you turn on the light the robot moves, but this time it turns toward the light because the sensor on one side drives the motor on the opposite side. Your friend says, “Oh look, it likes the light and is moving towards it.” But wait, something is drastically wrong. As the robot gets closer and closer to the light, each sensor gets more light, and this makes each motor go faster. The robot hurtles directly at the light with increasing speed. You friend screams, “Look out! It’s attacking!” as the robot hurtles into the light demolishing light and robot in one grand violent act. “Wow!” Your friend observes after a stunned silence. “That robot really hates the light.”

Imagine you painstakingly reassemble your robot. This time you add one more tiny change: a governor on the light sensors so that it increases speed until a certain light intensity is reached. Above that intensity the robot turns off the motor it is wired to.

Meanwhile, back in the gym, this time the robot turns towards the light and rushes towards it as before, but as it gets close it slows, and stops, and sits staring adoringly at the light bulb, never moving a motor. Your friend observes, “Oh look, it’s in love with the light.”

What has this got to do with you and me? Maybe nothing. But cockroaches, and bees, and most insects, have brains that connect to the same side of the body (muscles as motors) as their sensors, whether those are eyes or antennae. You and I have crossed nervous systems. The left brain controls the right side of the body and the other way around. Does that partly explain human aggression? And is the difference between love and violence a simple breakdown of the speed governor, the braking system? I don't know.