The idea that plants have some degree of consciousness first took root in the early 2000s; the term “plant neurobiology” was _【B1】_ around the notion that some aspects of plant behavior could be _【B2】_ to intelligence in animals. _【B3】_ plants lack brains, the firing of electrical signals in their stems and leaves nonetheless triggered responses that _【B4】_ consciousness, researchers previously reported.

But such an idea is untrue, according to a new opinion article. Plant biology is complex and fascinating, but it _【B5】_ so greatly from that of animals that so-called _【B6】_ of plants’ intelligence is inconclusive, the authors wrote.

Beginning in 2006, some scientists have _【B7】_ that plants possess neuron-like cells that interact with hormones and neurotransmitters, _【B8】_ “a plant nervous system, _【B9】_ to that in animals,” said lead study author Lincoln Taiz, “They _【B10】_ claimed that plants have ‘brain-like command centers’ at their root tips.”

This _【B11】_ makes sense if you simplify the workings of a complex brain, _【B12】_ it to an array of electrical pulses; cells in plants also communicate through electrical signals. _【B13】_, the signaling in a plant is only _【B14】_ similar to the firing in a complex animal brain, which is more than “a mass of cells that communicate by electricity,” Taiz said.

“For consciousness to evolve, a brain with a threshold _【B15】_ of complexity and capacity is required,” he _【B16】_.” Since plants don’t have nervous systems, the _【B17】_ that they have consciousness are effectively zero.”

And what’s so great about consciousness, anyway? Plants can’t run away from _【B18】_, so investing energy in a body system which _【B19】_ a threat and can feel pain would be a very _【B20】_ evolutionary strategy, according to the article.

【B8】________