Researchers have shown through a new study that pea plants showcase the ability to make adaptive choices based on variance – something that can be called gambling – a feature that has been observed in plants for the first time.
To put pea plants through the paces of making choices or rather forcing them to gamble – researchers grew pea plants with their roots split between two pots. Initial observations revealed that the plant grew more roots in a pot that had higher level of nutrients. Researchers then turned to splitting roots of each plant between two pots that had equal average nutrient concentrations, but where one pot had a constant level and the other a variable level, asking whether plants would ‘prefer’ to grow more roots in one or the other.
Based on theoretical analyses of how decision makers such as humans or animals respond to similar choices, the researchers predicted that plants might prefer the variable pot (ie be risk prone) when the average nutrient level was low, and the constant pot (ie be risk averse) when average nutrient level was high. Researchers believe that this is because when the average nutrient level is below what is required for the plant to thrive, the variable option at least offers the chance to ‘gamble’ on a run of good luck. On the other hand, when average conditions are good, it makes sense to take the safe option.
The researchers found that this is exactly what the pea plants did. Researchers say that this is for the first time that such a behaviour has been observed in an organism without a nervous system. While the findings indicate that the plants have capability to make intelligent decisions, researchers are not claiming that the plants are intelligent in the sense used for humans or other animals, but they say that it is possible – at least theoretically – to predict biological adaptations.
A human example illustrates the problem facing the pea plants: if you have a choice between a guaranteed $800, or tossing a coin to receive $1,000 for heads and nothing for tails, which one should you choose? Most people realise that the first option pays more on average. But imagine you are stranded with no money in a remote place, the fare to get home costs $900, and you are allowed a single toss of the coin. Now the coin-toss gives you an even chance of raising the funds you need, whereas the ‘safe’ option will always fall just short.
The pea plants were ‘risk prone’, meaning they grew more roots in the unpredictable pot, when the mean nutrient concentration of both pots was below 0.01g/L. They were ‘risk averse’, meaning they grew more roots in the constant pot, when the mean nutrient concentration was 0.15g/L or higher.