Unicellular Organisms are Capable of Learning, a New Study Has Revealed

After decades of research, biologists have finally made a significant breakthrough on the learning capabilities of unicellular organisms. Unicellular organisms, also known as single-celled organisms, are capable of learning, even with the absence of a nervous system.

According to the new study published in the Proceedings of the Royal Society B, just like animals adapt behavior and learn from experiences while living in fluctuating and potentially dangerous environments, unicellular organisms also to adapt to change for survival.

Habituation

In bid to prove that single-celled organisms are also capable of learning, the biologists studied a protist known as Physarum polycephalum, which is also commonly known as Slime Mold. They referred to this type of learning as Habituation.

The decision to study slime mold was because this unicellular organism has previously been found to successfully avoid traps, solve mazes, and even carefully streamline nutrition for the purpose of survival.

The protist was put under study for 9 days where the biologists challenged two groups and another control group with a harmless obstacle (caffeine or quinine). For the two groups, they had to pass through a “bridge” containing either of the obstacles while the control group was made to pass through the bridge without the obstacle.

Initially, the mold in the two groups was reluctant to pass through the bridge. However, after a while, they realized that the obstacle was completely harmless and therefore crossed over to the food source. After about six days, the two groups were behaving just like the control group.

This showed clear proof of habituation, in that the mold eventually learnt that the obstacle was after all completely harmless after repeated encounters.

Back to Old Habits

After the 9-day experiment period was over and the process repeated all over again, the biologists made an interesting discovery. After the process was repeated, they discovered that the mold in the experimental groups still distrusted the obstacle just like in the first scenario. It seemed like the memory had already expired in such a short time.

They also discovered that in certain scenarios, the slime mold habituated to caffeine but not to quinine and vice versa.

Habituation is a form of learning that exists in all animals. Until now, it has never confirmed in unicellular organisms devoid of a nervous system. This was an intriguing discovery.

From this study, biologists have been able to unravel the mystery surrounding the evolution of complex organisms, more so on their ability to learn and most importantly, it answers the question on how simple organisms are capable of learning.