/sci/ - Science & Math

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Does evolution play such an important part for plants as it does for animals?

probably random mutation like every other trait that ever has existed.
Then it was cultivated to be stronger by humans.

>>6391010
Plants have DNA too.
We come from the same source.

Even the grass is related to you.

>>6391025
And you didn't answer the question. You and I come from the same source (a womb), doesn't mean you are as important as me

>>6391039
Your question was "is evolution important as important for plants as humans"

Consider that every plant evolved from a common ancestor of us both, in an equal amount of time, (they have DNA too), it's obvious.

>>6391039
Survival of the fittest doesn't mean strongest or most advanced.
Evolution is a change in allelic frequencies in a population of organisms, or species.
Though some organisms are more complex the niches of the biosphere are still intact due to available resources.

Any organisms purpose is to contribute it's DNA to future generations. If a mutation provides any advantage at reproductive fitness the allelic frequency is increased until dominance of a gene is established within a population.

>How did marijuana come into existence in terms of an evolutionary perspective?
I don't know specifically, but selection favored its traits. If there is a widely accepted hypothesis I'm sure its on wikipedia or somewhere else you can easily google.

>For what purpose was marijuana (or more specifically THC) a driving or dominant genetic trait to form a new plant?
I don't know what you mean by "dominant genetic trait to form a new plant" could you clarify? If you're asking what the function of THC is, it is probably some kind of insect repellant. That is usually the explanation for why a plant produces a certain non-metabolic compound of interest.

>Does the plant have some symbiotic or other relationship with another organism that helps the survival of the plant?
Maybe, but I doubt it has anything to do with why THC exists.

>The compound is not found in any other plants, as amino acids and other chemicals are, so what evolutionary or natural law drove its distinction in a specific species of plant?
There are many compounds in any given plant that are found only in that species/genera/family. This is not a special characteristic of Cannabis. Two organisms are said to be different species if they don't interbreed and produce fertile offspring in nature. As in all organisms, the natural law that determines distinction as a species is genetic divergence to the point where the two varieties no longer breed.

>For what purpose was marijuana (or more specifically THC) a driving or dominant genetic trait to form a new plant?

THC is *one* of the 83 psychoactive compounds in cannabis and the 483 total compounds identified in the plant. THC by itself does not produce the sum total of the cannabis high but it is responsible for a large amount of it. Marinol or pure THC has been linked to several direct deaths while cannabis has been linked to none.

Most plants evolve psychoactives either as a defense mechanism against herbivores or insects (caffeine, pseudo/ephedrine), or as an attractant for pollinators or seed-spreading animals (capsaicin effects mammals but not birds and cannabis seeds are transmitted in the wild through avian means as well).

>>6391073
>Two organisms are said to be different species if they don't interbreed and produce fertile offspring in nature.

wrong. that's the definition they teach in high school biology class. look up the 'species problem' and you'll soon realize that defining a species is actually quite difficult for biologists/taxonomists

>>6391075
>Marinol or pure THC has been linked to several direct deaths...
Not OP, but I've never heard this before. Where did you learn this?

>>6391083
>There has never been a documented human fatality solely from overdosing on tetrahydrocannabinol or cannabis in its natural form,[35] though the synthetic THC pill "Marinol" was cited by the FDA as being responsible for 5 deaths (4 direct and 1 indirectly involved) between January 1, 1997 and June 30, 2005.[36] Information about the toxicity of THC is primarily based on results from animal studies. The toxicity depends on the route of administration and the laboratory animal. Absorption is limited by serum lipids, which can become saturated with THC, mitigating toxicity.[37]

>>6391087
and

http://medicalmarijuana.procon.org/view.resource.php?resourceID=000145#marinol

>>6391081
>wrong
not everything is purely wrong/right.
That is a useful and commonly applied definition of species. Obviously it doesn't work for bacteria or other asexual species, and there are problems such as ring species. "Species" is a term that is useful for many descriptions in nature, but it isn't a universally applicable concept. This doesn't make my definition wrong, it just means it doesn't work in all contexts. In the context of OPs question, its a perfectly valid definition.

>>6391087
Thanks for the sentence, but what is the title of the article that from?
>>6391094
interesting

>>6391096
>That is a useful and commonly applied definition of species

it's not very useful (there are many hybrid species that are entirely fertile and several have been established naturally) and the fact that it's commonly applied doesn't make it valid.

>In the context of OPs question, its a perfectly valid definition.

actually, it doesn't. cannabis may be divided into three species, c. satvia, c. indica, c. ruderalis that each have unique and distinct properties.

and all can interbreed and produce fertile offspring.

nature does not bow so readily to mankind's desire to classify.

http://en.wikipedia.org/wiki/Hybrid_%28biology%29#Hybrid_species

>>6391043
>>6391061
Let me rephrase. Is the competition for survival as important between plants than it is between animals?

Because panspermic aliens sought to establish a relationship with human psyches via the transmission of transcendental experiments, so they brought a plant to Earth that they could ensure would coeveolve with humans, thereby guaranteeing that one day a transcendental relationship could be established and humans could chill with the panspermic aliens in higher dimensions and smoke out of their cool Kleine Bottle bongs.

>>6391108
I never denied the existence of hybrid species. You seem to have missed one of the most important parts of the definition I gave. This is what I said, with added emphasis:
>Two organisms are said to be different species if they don't interbreed and produce fertile offspring in NATURE.
I realize you said that fertile hybrid species do in fact exist in nature. Hybrid species may often be unstable populations in nature that have lower fitness than either of their contributing species, and will go extinct eventually (unless they are maintained by subsequent hybridization events). If a hybrid population exists in this state, it would still be valid to describe its parent species as distinct enough. A hybrid species may also exist only at the boundary between the two parent populations, and nowhere else (this restricted range would likely be caused by the scenario i described above). Or perhaps the two species may not be justifiably labelled as separate species, mistakes can be made by taxonomists.

I completely agree that nature doesn't bow to our need to classify, but that doesn't mean my definition is useless, and I have seen the definition outside of high school textbooks. Biologists commonly use this definition.

How would you define species?

>>6391122
Finally someone tells us the truth...

>>6391008
>Then it was cultivated to be stronger by humans.
Mostly this.
Hemp was cultivated for centuries as a fiber.
Over time people realized if you burn a bunch of the hemp flowers you feel pretty good.
Apply that for a few thousand years and you get cannabis plants with higher levels of cannabinoids that get you high.
Then once you get into the 20th century and white people start smoking weed, they start doing intentional genetic engineering to select the dankest plants and you end up with bud that is several times as potent as even the traditional smoking herb.
It's the same reason why carrots are small and orange, bananas aren't gross and full of seeds and corn isn't some weird ass ghetto twig looking thing with huge seeds.

You should realize that modern 'dank' weed is a relatively modern invention, it's only been around for 30 or 40 years. Industrial hemp has very very low cannabinoid contents, like sub 1%, you'd have to really work to get high off of it unless you make (extremely inefficient) hash. Weed in the form that was used by people in the 60s and earlier and is still sometimes grown in Mexico and Paraguay is 5-10% cannabinoids, part of the reason it's so shitty is poor care of the plants as they are grown in unattended fields but the genetics aren't helping. But modern high grade cannabis is 25-30% or even up to 35% cannabinoids, it's an entirely different beast, all that beautiful white trichome fuzz is essentially a human invention.

As far as the original purpose of THC, I have no idea, the sticky cannabinoid-containing resin is used by female plants to catch pollen but I don't know if THC specifically came about for that purpose.

Gah I can't believe I wrote all that. This is what happens when a stoner takes a couple days off weed over break, lol.

>>6391140
>I realize you said that fertile hybrid species do in fact exist in nature

then why did you even post everything above in the first place?

>Hybrid species may often be unstable populations in nature that have lower fitness than either of their contributing species, and will go extinct eventually (unless they are maintained by subsequent hybridization events).

not necessarily, and several hybrid species have gone to produce sustainable populations naturally. notably, the ancestors of man continued to interbreed with chimpanzees after the divergence and evidence of hybridization has been discovered in many species since the 1950's as a common means of genetic flow, even in modern humans (chimpanzees, later denisovans and neanderthals)

>If a hybrid population exists in this state, it would still be valid to describe its parent species as distinct enough.

then it contradicts your definition regardless.

>Or perhaps the two species may not be justifiably labelled as separate species, mistakes can be made by taxonomists.

even across different genera? different families (guinea fowl x peafowl)?

either way, to justify the numerous cases of successful hybridization in biology as "taxonomist mistakes" would be absolute madness that would require reclassification of a vast amount of species.

>Biologists commonly use this definition.

as a stop gap because the actual question of defining a species is extremely complex and using a high school definition is easy to explain to people who are not experienced with biology or taxonomy.

>How would you define species?

the entire point i'm trying to make is that species is little more than a subjective definition that is hardly agreed upon by the consensus of the scientific whole and the species problem is still under extensive debate in modern times.

"... I was much struck how entirely vague and arbitrary is the distinction between species and varieties." - The Origin of Species p. 52

>>6390996
I believe the most commonly accepted theory is that when an herbivore ate it (could be a caterpillar, could be a cow) it felt very sick, and would not want to eat it again.
Obviously this effect isn't the same on humans, though it may be enough to cause them not to want to eat it in nature.

Of course, like every other drug, from habanero peppers to coffee, we humans are so weird that we actually like the effects of things that are meant to ward us away.

>>6391087
Note: "deaths" does not mean "human deaths"

>>6391167
Based on your responses, I feel like we don't really disagree fundamentally:
>the entire point i'm trying to make is that species is little more than a subjective definition that is hardly agreed upon by the consensus of the scientific whole and the species problem is still under extensive debate in modern times.
This is exactly true, but its not like biologists never use the word "species". Its a useful concept.

You also seem to be assuming that for all of the scenarios I described, I take the most extreme stance of "this is always the case". (e.g. >either way, to justify the numerous cases of successful hybridization in biology as "taxonomist mistakes" would be absolute madness that would require reclassification of a vast amount of species.)

My original point, which I stand by, can be summed up as such:
"One definition of species is 'Two organisms are said to be different species if they don't interbreed and produce fertile offspring in nature'. This definition is not universally applicable, but it is useful in many cases for describing populations in nature. Other definitions of 'species' can be used for other contexts, or the concept of species may not be useful at all. It is entirely context dependent."

Just because one definition of "species" isn't universally applicable doesn't make it invalid.

>>6391109
Yes, very important.
For instance, plants can't move, and must rely on different methods of protecting themselves and getting their nutrients.
Even heard of plants choking each other out? How about plants that secrete insect killing saps? Poisonous berries? etc..

>>6391184
>Even heard of plants choking each other out?
Actually no I haven't.

>How about plants that secrete insect killing saps? Poisonous berries?
Is that competition between plants or competition between plants and animals?

To me it feels like plants don't have to adapt to other "predator plants" in order to survive, but maybe I'm wrong. I guess they do have to adapt to animals eating them.

>>6391183
>This is exactly true, but its not like biologists never use the word "species". Its a useful concept.

i already explained this to you.

>You also seem to be assuming that for all of the scenarios I described, I take the most extreme stance of "this is always the case". (e.g. >either way, to justify the numerous cases of successful hybridization in biology as "taxonomist mistakes" would be absolute madness that would require reclassification of a vast amount of species.)

because there is no objective measure defining the amount of hybridization that needs to occur to quantify the same species. it's based off of phenotype, not genotype, and that makes it a fundamentally flawed construct. there is no means to draw the line other than opinion as the amount of species that possess hybridized DNA or are hybrids entirely are vast.

>"One definition of species is 'Two organisms are said to be different species if they don't interbreed and produce fertile offspring in nature'. This definition is not universally applicable, but it is useful in many cases for describing populations in nature. Other definitions of 'species' can be used for other contexts, or the concept of species may not be useful at all. It is entirely context dependent."

science does not function on what is useful, it functions on what is true, and I would argue that pushing a misguided, constantly debated, fundamentally subjective, colloquial view of taxonomy onto the common person only serves to sow future ignorance.

>>6391178
The FDA does not report animal deaths in regards to its approved drugs intended for human use.

>>6391203
>science does not function on what is useful, it functions on what is true
In order to figure out what is true, we need to be able to communicate what we mean. Using a word with a limited definition is perfectly acceptable as long as it is understood what the limits of the definition are, and you and I and any biologist worthy of the title is aware of that limitation.
>and I would argue that pushing a misguided, constantly debated, fundamentally subjective, colloquial view of taxonomy onto the common person only serves to sow future ignorance.
I would argue that explaining things to the layman in the most rigid technical way possible, listing every caveat along the way serves to sow ignorance far more than using limited definitions. Giving a partial answer to somebody's question is preferable to giving no answer at all.
Also using more adjectives doesn't make you more right ;)

>>6391219
to clarify
>Giving a partial answer to somebody's question is preferable to giving no answer at all.
I say "no answer" because people will stop listening when they don't give a shit about technical details.

considering you can only get thc from burning it it probably does not have any evolutionary purpose

>>6391352

>>6390996
>How did marijuana come into existence in terms of an evolutionary perspective?

"Like most pharmacologically-active secondary metabolites of plants, THC in cannabis is assumed to be involved in self-defense, perhaps against herbivores.[10] THC also possesses high UV-B (280–315 nm) absorption properties, which, it has been speculated, could protect the plant from harmful UV radiation exposure."
http://en.wikipedia.org/wiki/Tetrahydrocannabinol#Pharmacology