Math and logic in the Venus flytrap
Steve Taranovich - February 06, 2016
NY Times Science Writer, James Gorman, commented recently that a Venus Flytrap can count.
Dr. Rainer Hedrich from the University of Würzburg, in Germany has demonstrated this counting
mechanism in the Venus Flytrap. See this article. This carnivorous plant captures and digests insects
in order to live. The method is two leaves that senses an insect, snaps closed and introduces
digestive juices to dissolve the prey. This method of getting sustenance allows the plant to grow and
exist in even poor soil devoid of nutrients.
The process is as follows: An insect lands on or crawls into the center of the two leaf traps and as
they move, numerous hair-like triggers on the leaves sense that the future meal has touched the
trigger hairs and the leaf trap snaps closed.
As it turns out, researchers were always aware that false triggering by raindrops or other flying
particles necessitated touching the trigger hairs more than once. Recent studies determined that the
plant system was actually counting the electrical pulses from the prey’s movements.
Since plants have no actual nervous system like humans and animals, the electrical impulses are
produced biochemically on the plant cell’s surface. Further detailed investigation and experiments
showed that the trigger hairs actually need only two such triggers within 20 seconds in order to
snap the trap closed. The amazing fact here is that the plant cells somehow remembered and stored
the first trigger signal for a brief time! Plus, after 20 seconds, the memory of this trigger was erased
if no other signal was received and some sort of reset process allowed the process to begin again
waiting for the next signal of movement ---hence the prevention of false triggers .
Now comes the next amazing step in this process---In order to emit the digestive juices once two
hairs are sensed within the 20 second period and the trap snaps closed, a third trigger to a hair must
be sensed to start that process.
That’s not the end of this amazing process---as the insect struggles to get free, its movement lets the
plant know to keep sending in more digestive juices proportional to the prey’s movement until the
insect us fully motionless and dissolved.
The plant uses up only enough energy to produce digestive enzymes when they are needed and only
in the amount needed, thus creating a very efficient process for the plant’s survival.
Dr. Hedrich found that electrical signals were produced by biochemical changes and from a process
which started very early in the plant’s life. “A single cell can be electrically excited,” commented
Hedrich.
The Venus Flytrap is nature’s simple, primitive mechanism with an electrical system and computing
engine that can do simple Math! This plant has been using electricity and logic eons ago before man
ever conceived electricity’s concept. There is an entire discipline in science called The Distributed
Trigger Counting (DTC) Problem that is based upon the simple Venus Flytrap mechanism. Reference
1 has tackled this problem and created an algorithm for multiple triggers. See Figure 1 and 2.
Figure 1: Here is a simple network topology of five processes (Image courtesy of Reference
1)
Figure 2: A DTC algorithm for receiving w triggers (Image courtesy of reference 1)
Perhaps mankind should take some more lessons from the simplicity of nature in other areas; there
are certainly many cases in which we have done so in science and engineering. Can you name some?
Observation is the key; analysis of a basic system and expanding upon it can lead to great creativity
and solutions to improve our existence on this planet called Earth.
References
1 Efficient Distributed Trigger Counting Algorithms for Dynamic Network Topology, C. Chang, J.
Tsai, IEEE Transactions on Signal Processing 2015