Intelligence in Nature - Jeremy Narby [42]
Nakagaki said that a true slime mold turns into an efficient tubing network by contracting and relaxing its body in waves. By varying the rhythm of the contractions, it can move its gelatinous contents either inward or outward. For example, when food is sprinkled on a slime mold, its contractions change drastically. These contraction patterns are self-organized, as there are no leaders or conductors in the protoplasm; rather, parts of the homogeneous slime interact in a synchronized way. Just how this kind of self-organization works is a serious question for mathematics and theoretical physics, according to Nakagaki. âSo in this organism, there is no nervous system, no brain, but it has the ability to solve difficult mathematical problems. But the way of computation of this organism is quite unknown,â he said.
The rhythmic contractions that ripple across the slime mold and allow it to move are regulated by a complex mechanism that has yet to be elucidated. So far, researchers have determined that different substances participate in the regulation of these contractions, including charged atoms of calcium, which oscillate. These biochemical oscillators may give rise to waves that propagate through the slime moldâs body and that seem to lead to the development of tubes. But the details remain obscure. Nakagaki thinks the way forward in understanding how a slime mold does what it does is to proceed with mathematical modeling of its behavior, and in particular of its contractions. Understanding what happens in the contraction patterns from a mathematical point of view would allow one to understand how it self-organizes its movements. This, he said, was the main subject of his current research.
I asked how his work had been received by the international scientific community. He said that he goes to international conferences on applied mathematics and physics, and that researchers in these fields have welcomed his work. But he had hardly received any responses from biologists. I found this surprising and asked why he thought it was so. âRecent biologists work on molecular biology,â he said. âTo such people, it does not matter how the biological system works. They are, in principle, only chemists.â He laughed. âBut biologists in the field investigating the behavior of animals like my results.â
My impression was that an increasing number of scientists were opening up to the idea of intelligence in nature. I asked Nakagaki whether he agreed. He replied that after publishing his research on maze solving by the slime mold, he had become more careful in his use of the term intelligence. Its definition seemed to change from one person to the next, and some critics argued that the slime moldâs behavior could not be considered intelligent because they did not believe it solved the maze by conscious decision.
I asked how those critics could be sure that a slime mold is not conscious.
âI donât know,â he replied. âBut, Iâll say it again, consciousness is the small tip of a large mountain.â He considered consciousness to be a useful term to refer to self-awareness, as when humans observe themselves observing themselves.
I doubted that introducing concepts of consciousness and self would cast much light on intelligence, if only because the workings of consciousness and the nature of self remain obscure. Nevertheless, Nakagakiâs research showed that the slime mold computes. And many consider computation to be among humanityâs finest intellectual achievements. I asked him about this.
âThe slime mold computes,â he replied, âbut this process corresponds to the unconscious level, I think.â He stood up and wrote unconscious