Originally posted by Paul Dirac IIPlants do have something similar to a nervous system already, and because of this they can respond to stimuli to varying degrees (such as turning their leaves towards the sunlight). I don't see why they couldn't in time evolve something like a brain (which at it's most rudimentary is really just a bundle of nerves anyway). A brain comes at a cost though, so it would have to be useful in plant survival, or it would be selected against. You can imagine that a plant that could determine if a given insect would be good for it or not can change its appearance to either attract or repel an insect at any given time, could make good use of a brain. But evolution is not a directed process, so whether or not this will happen is impossible to predict.
Is there any expectation that evolution will create plants with a nervous system and some degree of logic processing?
Originally posted by C HessI do not think 'nervous system' would be the right term though. Plants do engage in various sorts of messaging both around the plants body and also between the plant and other plants or animals.
Plants do have something similar to a nervous system already,....
Originally posted by twhiteheadI did write: "something similar to a nervous system", for a reason. There are cells in plants that are similar to nerve cells in animals. They generate electrical signals that propagate through the plant, but it's not clear exactly how these are used in plants. I would say that what makes something a nervous system is simply the ability to sense (to react to stimuli), it doesn't need to include a brain (a nerve net is an example of a brainless nervous system).
I do not think 'nervous system' would be the right term though. Plants do engage in various sorts of messaging both around the plants body and also between the plant and other plants or animals.
But animals do this too in many different ways for example using hormones or pheromones. Yet we would not really call hormones part of the nervous system. The ne ...[text shortened]... system is an organ whose primary functions are sense, communication and in many cases, thought.
Originally posted by C HessYes, I wasn't disputing your post, just trying to clarify.
I did write: "something similar to a nervous system", for a reason.
Originally posted by twhiteheadIn my first post I was talking about a sensory/response system in general (and heliotropism would be an example). In my second post I bring up electrical signals in response to your post, only to point out that there are cells that resembles neurons in plants, though it's not understood exactly how they're used.
Can you give any references? That is not how they turn towards sunlight as far as I know.
Originally posted by twhiteheadTo be honest, I'm not exactly sure where I would draw the line.
So would you call the process of getting a sun tan indicative of a nervous system? What about hormones?
Originally posted by C HessThere are plants that follow the sun by time of day, and others that just generally grow towards the sun. There is also the tendency to grow vertically ('sensing' gravity), or in the case of climbing plants, to move in a spiral.
But for a plant, turning leaves towards the sun is a relatively fast response.