Intelligence & Evolution: pea plant risk taking (Evolution)

by David Turell , Friday, July 01, 2016, 02:18 (3066 days ago) @ dhw

If a pea plant has rooting choices it will chose to take a risk if the supply of nutrients is dice:-http://phys.org/news/2016-06-pea-ability-gamblea.html-"An international team of scientists from Oxford University, UK, and Tel-Hai College, Israel, has shown that pea plants can demonstrate sensitivity to risk - namely, that they can make adaptive choices that take into account environmental variance, an ability previously unknown outside the animal kingdom. -"In the study, published in the journal Current Biology, pea plants were grown with their roots split between two pots, thus facing the decision of which pot to prioritise.-"In a preliminary experiment, the researchers showed that the plants grew more roots in a pot endowed with higher levels of nutrients - an adaptive response similar to animals allocating greater foraging effort to richer food patches. In a series of follow-up experiments, they then split the 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.-"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.-***-"'To our knowledge, this is the first demonstration of an adaptive response to risk in an organism without a nervous system. We do not conclude that plants are intelligent in the sense used for humans or other animals, but rather that complex and interesting behaviours can theoretically be predicted as biological adaptations - and executed by organisms - on the basis of processes evolved to exploit natural opportunities efficiently.-"'We do not yet know how the plants' sense variance functions, or even if their physiology is specifically adapted to respond to risk, but the findings lead us to look even at pea plants as dynamic strategists and to model their decision processes just as one would model an intelligent agent."-***-"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.-"Efrat Dener, now a master's student at Ben Gurion University, Israel, and the study's first author, said: "Like most people, including even experienced farmers and gardeners, I used to look at plants as passive receivers of circumstances. This line of experiments illustrates how wrong that view is: living organisms are designed by natural selection to exploit their opportunities, and this often implies a great deal of flexibility."-Comment: I'm not surprised at the findings. In the unpredictable pot at low concentration, more roots means more root searching for scant food, while at the higher level the plant is getting a satisfactory supply so extra root growth supplies more energy. All could be based on sensory programming. As usual the living organisms are very inventive in arranging for survival.