Studies like this are an anathema to genetics, because they show a clear and meaningful connection between the generations that is the very opposite to the “random” mutations theory that effectively posits that each life is essentially meaningless and leaves no footprint on the world upon its end, unless there was a mutation that occurred during that lifespan. Even then, the mutation is only considered important if it confers a change to the organism that increases survival and/or reproductive fitness. Since such changes/mutations happen on evolutionary time scales – tens of thousands of years.In other words, the experience that our ancestors had are meaningless and so are ours, and what we learn in life is irretrievably lost to future generations. Recently, several studies have conclusively disproved that bizarre and nihilistic position. Namely, experiments with flies, worms, rodents and even monkeys have shown without a doubt that memories are passed down to future generations, and affect the physiology and behavior of future generations in profound ways. The study below now extends this “memory inheritance” to plants as well, further corroborating the idea that memories/knowledge acquired throughout a lifespan are far from useless, and each generation possesses effectively the composite knowledge of all prior generations. This idea is very much in line with Rupert Sheldrake’s idea of morphogenetic fields, and knowledge “pooling” available to all future generations. In any event, one of the most important takeaways from the studies below is that memories of parental adversity are subject to a very clear trade-off. The offspring of organisms that endured adversity throughout their life apparently have increased survival fitness and robustness, but at the expense of stunted growth and reduced reproductive capacity. The opposite also seems to be true. Namely, children of parents that never experienced adversity inherit that those “memories” of optimal psysiological state and are optimal themselves. The resilient offspring are also much less attractive to agents of adversity, while the offspring of parents that never experience adversity enjoy increased growth and reproduction, but are much more attractive to the agents of adversity (e.g. “predators”, in the most general sense). It reminds me of a poem I read long ago as a child, which stated that demons are afraid of their own, but love to mess with angels:-)
https://doi.org/10.1111/pce.70067
https://doi.org/10.1002/pei3.70070
https://doi.org/10.1111/pce.15558
https://doi.org/10.1016/j.envexpbot.2024.105944
https://news.uark.edu/articles/79844/soybeans-seem-to-inherit-the-bad-memories-of-their-parents
“…When soybean plants survive attacks frots and periods of drought, they remember. While plants don’t remember in the way animals do, research out of the Arkansas Agricultural Experiment Station shows that soybean plants can pass on adaptive responses to stress — like those hungry insects — across generations without changing their DNA. Scientists call this kind of adaptation across generations “transgenerational plasticity,” and the consensus has been the independent stressors of drought and herbivory, or animals feeding on plants, can induce gene expression — possibly through epigenetics. Unlike genetic changes, or mutations, epigenetic changes are reversible and don’t change the DNA sequence, but rather how an organism reads its DNA sequence.”
“…Kariyat and his doctoral candidates conducted multi-layered experiments to test if soybean plants under drought stress are more vulnerable to insects and how much of the parental plant’s memory — its response to stress — is passed on to its progeny to cope with specific kinds of herbivory. Progeny of stressed plants had seeds with higher nitrogen and protein content, key markers of plant fitness. Offspring also produced more flowers and had a greater density of trichomes, the tiny hair-like structures that defend against pests. Kariyat noted that these positive effects were strongest when parent plants experience both drought and herbivory pressure. Despite these advantages, the stress memory came at a cost — strong defenses but weaker growth. Stressed progeny showed reduced yield, including a higher rate of empty pods. Defensive trichomes also declined with maturity, suggesting that the enhanced defenses may be short-lived or age-dependent. The research suggests that there is a costly trade-off between survival and productivity, Kariyat said. Kariyat concluded that their research so far points to stress memory in soybeans being a double-edged sword. While it can improve defense and early vigor, it also leads physiological trade-offs that ultimately reduce fitness and yield.”
“…To see whether insects could detect past drought stress in soybeans, the researchers built tiny bridges between previously drought-stressed plants and plants that had consistently received enough water. They observed soybean looper caterpillars pausing, rotating their heads and often reversing course back to the healthier plants, the study noted. The scale of damage by the caterpillars on consistently watered plants was significantly higher than the plants that had recovered from drought stress, supporting the “plant vigor hypothesis” that pests prefer robust hosts.”
