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Evolution of nepenthes

  • #21
Really nice discussion!

I have got another example for 'recent' mutations: Ne. lowii. It grows at Gunung Mulu, Trusmadi and Gunung Murud. And all forms got different pitchers. So the pitchers of Gunung Murud and Trusmadi are smaller than those of the Gunung Mulu variety.
 
  • #22
Nepenthes are truly an old species. First it exhibits a prehistoric pollination method of being dioecious (separate sexes on separate plants), examples of dioecious flowering occurs in other prehistoric old plants (i.e. cycads).

These plants had to evolve to insectivorousness due to lack of nutrients in their heath-bogs and rocky outcroppings. A significant supply in water was the determining factor in allowing diversity to happen. Even to this day, nepenthes can only occupy areas where rainfall is high. These plants lack any succulence or thickened stems or tissues that allow these plants to sit through droughts. Thus steady and reliable rainfall was not a factor in developing these plants. So since water was not scarce or difficult to obtain, these plants had to adapt to other strategies related to the environment. Since many nepenthes occupy areas where soil nutrients were poor or the soil had high concentrations of serpentine or ultramific layers, this prevented other plant species which are more faster and evasive from getting established. It is my belief that many nepenthes species rely on the shelter of a more aggressive species to get a start next to. These competitors started out with ample supply of nutrients and moisture, but eventually their roots ran into a higher PH soil or soils where calcium, magnesium and lime was high, thus stunting its growth and preventing an otherwise evasive species to outshadow the weaker and slow growing nepenthes. Nepenthes which have the ability to trap its own food for nitrogen and other trace minerals, soon could get a faster foothold on their environment and soil nutrient and combined with an endless supply of water and sunlight, now can overtake the small stunted tree or sapling.

What I also believe is that many nepenthes are high pH requirement growers and many people do not realize that they need this in order to develop properly. I believe that many nepenthes grow acidically in the seedling age and until their root system digs deeper into the substrate, they will soon require a higher pH soil. It is simple to understand that nepenthes grows acidly. Most upper layers over a bedrock of coral (as with most of the pacific islands) have a shallow decomposed region of plant material making a thin layer of acid or composted material. Once the plant penetrates this layer, then and only then do they exhibit some of their true characteristics.

I have a plant labeled northiana x (spectabilis x veitchii) and since I read somewhere that northiana grow in a very basic soil, I repotted it into a deeper pot with the bottom third composed of pure coral chips. I added layers of coco bark and fir bark and even coarse peat moss and hapu'u (fern fiber) to this mixture.
I later learned that this wasn't a northiana cross, but a bicalcarata cross and by then the plant had developed into a very heavy growing species with leathery leaves and robust pitchers. I have another clone of this same cross growing in a different area in lmost pure peat and coco bark mix. It is softer and more bigger leafed than the plant in this media.

Oh well, I seem to be going off track. I will perhaps start another section with regards to this topic. Sorry for boring everyone.

More later,

M
 
  • #23
Rainforest Guy that it a very interesting observation. Hmm I should try it on something.
 
  • #24
interesting post RainforestGuy. still pondering...Thanks. Welcome by the way!
Ok guys, so what do you think caused the evolution of the large teeth in edwardsiana, and macrophylla? perhaps a large insect now extinct that could work its way out of a regular peristomed nep, but could not escape the larger stiffer hooks of edwardsiana? I am truly baffled by this. there has to be a reason...
 
  • #25
To precent stealing of prey by mammels.
 
  • #26
Thanks for the reply Treaqum, but that theory has already been disproven. Neps are no match for mammals.
 
  • #27
Ah I see. Where is the paper that disproved this? I would be very interested in seeing it.
 
  • #28
Oops, guess I should have something to back up my statement eh' lol. I seem to remember reading somewhere that monkeys raid neps for the bugs inside. They don't reach in the pitcher mouth though, they just rip it apart. Poor neps don't stand a chance. Sorry i don't remember where i read it. Perhaps some other members could confirm or deny?
Thanks,
Robin
smile.gif
 
  • #29
It only has to lower the percentage of stolen food from mammals to be useful... it doesn't have to stop it completely.
 
  • #30
beautiful thread indeed!.
Regarding unique nep species such as pervillei, we should not forget to add viellardii, it may have evolved differently as well.
Some time ago, i wrote to Dr. Clarke regarding the variability of pitcher size, colour, and shape. Again, the question was why are there so many species types in a relatively small area when the amount and type of prey available to meet their nutritional needs is also a limiting factor!. Competition perhaps?
I think in one of his books, he measured the type of prey trapped by three different neps: two different species and a hybrid derivative between the two.
Unfortunately, he could not see a clear trapping pattern amongst these three plants.
Regarding rowanae in Northern Australia, IMO, there are at least 3 species with some hybrids all lumped into one group.
Evolution is not a casual event, but a constant one.

Gus
 
  • #31
good point endparenthesis
, but again, the mamal in question...tree shrew , monkey, or whatever don't geta t the inecsts from the peristome, they would chew thru the base of the pither or shred it entirely. I imagine most monkeys have some huuge caluses from all the tree swinging, and would not even feel the peristome of edwardsiana, much less be disuaded by it. That bieng said, you could be right. ;)
Another good point Gus. So if the prey is the reatively the same for all pitchers regarless of peristome type or shape, perhaps they developed differently for some other reason... hmmmmm Anyone know what edwardsiana eats?
 
  • #32
those toothy peristomes look like they are wanting to keep prey from getting out, not stopping anything from getting in. I wouldnt think anything would taste very good that has been in a trap for a while.
I am a noobe, so I am sure this has been said before.
 
  • #33
i agree Machete the toothier ones look like they are for keeping things inside the pitcher, Thus my question. What they heck is edwardsiana trying to keep from escaping? Some Giant agro bug that can climb the inside of the pitcher, but cant get it's legs past the hooks? Same question for upper hamata pitchers. I know the teeth function by making the ants get to the sharpest point to get nectar, and of course they can't hold on, and slip in, so that makes sense for something like villosa or hamata... more teeth. more places for insects to feed and slip, but edwardsiana only has like 10 teeth. Not very efficient for feeding, so they must be for keeping something in. right?
Please forgive my amatuer questions.
Robin
 
  • #34
Perhaps it's keeping smaller vertebrates like birds out? Or smaller, insectivorous primates like tarsiers? Certainly, they wouldn't have the strength to tear open very large pitchers. Even in the case of edwardsiana, I don't think that feeding is out of the question either, because you don't need lots of hooks to make the bugs climb out on a limb and fall in - you only need one. N. edwarsiana could be moving towards less hooks because it's easier to produce a few and just as effective for trapping. The Heliamphoras seem to do just fine with one nectar cap.
~Joe
 
  • #35
What about lizards? I mean keeping them out. You know they look in everywhere so in bical if they backed up to fast (wack) and you you have a speared lizard. And beleve me you can punch two little holes in your skin with a bical pitcher by mistake. I will NEVER pur my finger in a bical pitcher again that hurt like no other.

As a side note anyone have any idea why mnay species and hybrids have pink-purple splotches on the upper half of the inside of the pitcher? Do you think it is supposed to attract something?
 
  • #36
just saw this post... :-/. I didn't read it all, just a couple of the last replies.
didn't someone post a picture of a bical where ants crawled down the teeth and later fell and was digested? maybe teeth in bicals and other species help by leading the insects and making them fall (doesn't the nectar make them drunk?)
but what about the spikes on the lids of some like lowii and that other relative of lowii?
 
  • #37
The spines on lowii are thought to attract birds, which defecate in the pitchers. If you look on the uppers of a healthy lowii, you're supposed to be able to find little white balls of nectar. The birds sit on the pitcher to eat the nectar and leave a little 'foliar feed' behind.
Tre, I've read that the splotchy color pattern is supposed to 'lead' insects somehow, but the cause and effect behind it never seems to follow whenever I encounter it.
~Joe
 
  • #38
[b said:
Quote[/b] (JustLikeAPill @ May 24 2005,12:32)]if N. madagascarensis is the oldest, that's interesting since it's rather unremarkable, unlike N. hamata or N. platychilla or others.
definitely makes sense though, right? like when cars first came along, nearly every single one was a standard model T... now there's everything from Mini Coopers to Hummers.

start with the basics then specialize as needed
smile.gif

(edit: hehehe yeah i know i catch on late... but this is definitely an awesome thread!)

aren't there a few nep species that have a symbiotic relationship with ants? the name escapes me but i think i saw a National Geographic article on them at some point. i wonder when/how that came about....
 
  • #39
I think those downward pointing teeth would be for ants and whatnot to teeter on the edge and then slip into the trap. I suppose it would make it a bit harder for an insect or whatnot to get out.
 
  • #40
Moonflower, I've heard that lots of different Neps will dry out their traps but still secrete nectar from the leaves during droughts in order to keep their affiliated ant colonies healthy. There are some more sophisticated adaptions as well, but I just think it's neat that they feed the ants without trapping them.
~Joe
 
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