Date: Fri, 20 Oct 2000 14:09:05 PDT From: "Steve Klitzing" <starbirdcom@hotmail.com> To: cp@opus.hpl.hp.com Message-Id: <aabcdefg3029$foo@default> Subject: Evolution of CPs
It's interesting to note that many plants catch water in basal leaf joints,
pitchers, flowers, etc. Many other plants are sticky to the touch. Many
grow in fluted forms and have something resembling an open vase. Yet, only
a few of these plants have developed a true carnivorous nature. Many plants
will absorb nutrients through their cell walls. Foliar feeding on many
types of plants proves this. It seems only a few types of plants, through
natural selection and poor environment, have outcompeted other similar
plants by being able to absorb nutrients with means other than roots. Those
that outcompeted others on poor soil were able to grow larger and
proliferate when other plants languished. Over millions of years, these
plants became CPs. But, in a sense, isn't every plant carnivorous? You
could consider a bromeliad a CP since it sits in the jungle and draws
nutrients from dead and dying matter that falls into its vase. That
includes insects. There are other plants, considered non-CPs, that draw
nutrients through leaf cells. The mechanisms CPs have evolved are only very
minor extensions of what other plants have. A sticky leaf is a sticky leaf,
it's just that a Sundew does better at foliar feeding. A nepenthes leaf
with tendril and trap is not that much different than a Dutchman's pipe or a
snapdragon. The difference being that the pitchers, which were probably
once flowers on the end of a vine, evolved to a different purpose when food
kept landing in it and drowned in the pool of water in the flower.
Sarracenia, Heliamphora, and Darlingtonia are just variations on tubular
leafy plants and lilies that got lucky in the gene pool game in the fight
over poor soil, drought conditions, and fire. A slight genetic edge was all
they needed to thrive. It would be interesting if bromeliads eventually
gain carnivorous characteristics. And, if VFTs started out like Mimosa, but
with the ability to close sticky leaves together when something landed on
it. Originally, this ability could have been a plant defense mechanism
(VFT's and Sundews) which eventually became a feeding feature. As for
pitcher plants, it may be that they had a common ancestral type of plant
which also gave rise to bromeliads. When the jungles receded from North
America during and after the ice ages, they left behind a lot of weird
plants and evolving species to fill up the eco-hole. Joshua tree, to name
one. A tropical plant that adapted to the desert. Some adapted to harsher
and cooler conditions. It's also possible that a lot of drosera were
deposited worldwide because their seed is so small and light, and could
easily have been blown into the jet stream by storms. This happens to
orchids.
---Steve Klitzing
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