Why aren't all plants poisonous?

why aren't all plants poisonous this is a question I started asking lots and lots of people when I was about 14 I started by asking my biology teacher at school which was a mistake because she was as thick as three thick planks but then I asked somebody else's biology teacher and got a much better more interesting answer but one that I knew was wrong I didn't know what the right answer was but I knew the answer he gave me was wrong and I started asking pretty much anyone I met that I thought you might have an opinion on this or some knowledge on this that would be useful for answering the question I farmers I asked farmers they gave me very good very interesting our answers that taught me a lot but I still I knew that they were wrong they they tend to have a functional view of plants so this plant is full that no no no plants don't have a function like that unless they've been bred for that function by a man I'm talk about wild plants why aren't plants the normal plants all poisonous because what is a leaf well it it's the plants Bahgat it's solar-panel it's where it gets its energy and it's definitely to a plant disadvantage to be eaten by a passing goat so why aren't they all poisonous and I asked Maureen when I to university I was asking professors of botany you you think they'd probably have an answer wouldn't wouldn't you this question and you know even they were giving me answers that I knew were wrong I still don't know what they what the actual answer was but then suddenly but it like a great blurry from the hint or most it just hit me all smash and flaky they was the reason that plants aren't all poisonous is because evolution is not a force towards the optimum it's a force towards the minimum necessary and if grass say is not poisonous and it survives despite not being poisonous and passes on genes and there's more grass that isn't poisonous well if it does then it does if a plant is able to survive despite not being poisonous then hey presto it carries on not being poisonous if for instance humans if eyebrow ancestors had fur and we're endlessly strong like our modern-day gorillas but we then learned how to make clothes and tools we meant that we didn't have to be so strong I didn't have to have further after a while you lose your strength you lose your fur if there's no pressure to make you that if that thing's not necessary for your survival then gradually you lose it and so you know that for a while was announcer to the the mystery that contented me until I realize that actually no there was a second revelation when I realized something years later that action that wasn't quite right either though I was right about the evolution not being a force towards the optimum the reason that plants aren't all poisonous is sort of an illusion brought on by the fact that we have evolved a tolerance for those toxins in fact all plants are poisonous yes I'm going to say that again just in case you you think hang on What did he say I say to get all plants are poisonous absolutely all plants have got toxins in them of the salt that harm animals but animals you see have been evolving alongside the plants and every time the plants get a little bit more poisonous the animals get a little bit more resistant to the poisons and how resistant an animal is to poison depends pretty much on where it is in the herbivore carnivore omnivore scale of things depending on what their diet is so for instance the deer a deer can browse on all sortsa plants that would kill you stone dead very quickly we humans we're only boars and we are fairly resistant to some the plants most plants will do us a lot of harm but enough plants are to us not particularly dangerous and so we can carry on living great and something like a cat if that's what some people photos are true carnival your moggy is tolerant to the toxins in very very almost no plants at all if you want to see a molecule ECAP quickly give us some celery be very difficult to persuade to eat it but you know there are some things that for us of food that will kill a cat stone dead and simile there are plenty of things that for a deer a food that'll kill a stone dead most blood a variegated turn how splotchy that's not within the silver stripes but if they're lethal about half of one leaf will kill an adult human so there you go all plants are poisonous but we have tolerance to some plants

Channel: Lindybeige

Views: 179,756

Rating: 4.9214554 out of 5

Keywords: plant, toxin, poison, animals, diet, eat, digest, biology, question, evolution, grass, tree, shrub, deer, carnivore, herbivore, omnivore, tolerance, natural

Id: 6ClQXwkkH8A

Length: 4min 49sec (289 seconds)

Published: Wed Mar 03 2010