Carnivorous Plants (unpublished)
Mark Stewart
There are no man-eating plants, however there are
a number of plants
that do trap and consume insects including the sundew, the bladderwort,
the
butterwort, as well as the venus flytrap.
The carnivorous plants, like the venus fly trap
and the pitcher plant,
demonstrate intricate design. These plants have the ability to not
only
attract but also capture and digest animal victims. Concerning the
piecemeal
evolution of the carnivorous plants, F.E. Lloyd in the introduction
to The
Carnivorous Plants, conceded that the evolution of the specialized
organs of
capture defy explanation.
In the Venus Flytrap the tendrils of the plant are
leaflets that snap
shut to trap insects, which are then digested by enzymes produced by
the
leaf. In the Pitcher plant leaves, tubes containing fluid trap the
insects
that fall into them and again, are then digested by enzymes.
The insectivorous Pitcher plant occurs in bogs.
Water that collects
inside the pitcher becomes stagnant. It's probably this stagnant water
that
attracts tiny insects. Inside the pitcher are a series of stiff waxy
hairs
that point downward. The insect can easily slide past them into
the pitcher
but then finds himself trapped. Often digestive enzymes are secreted,
but
sometimes simple decay processes provide the materials absorbed by
the
plant.
The best known of the carnivorous plants, of course,
is the venus
flytrap, which is native to the sands of North and South Carolina.
Its leaf
has stiff spines that interlock like the jaws of a bear trap. The trap
is
triggered when an insect lands on the leaf and touches two or more
of the
hairs found on the leaf surface. The leaf springs shut so quickly that
the
insect cannot escape. The leaf squeezes so tightly that it is often
possible
to see the outline of the insect in the leaf trap. When the insect
has been
digested by the enzymes that are secreted, the trap reopens.
There are two phases of trap movement. Closure,
which takes place
quickly upon the stimulation of the trigger hairs inside and squeezing,
where the trap presses inward on the insect prey. It has been demonstrated
that any two taps, even by mechanical stimuli, of the trigger hairs
will
lead to rapid closure. This trapping motion results from an action
potential
wave, much like the wave that moves along a neuron in an animal.
A different mechanism is involved in the squeezing
or "narrowing". Inner
trap surfaces secrete acid digestive juices which at first kill the
insect
prey and later digest it. When the insect dies, it releases haemolymph.
When
artificial solutions of sodium and/or ammonium ions (of low concentrations
approximating those found in ant haemolymph) were pumped through the
closed
traps, the traps squeezed more tightly shut. Solutions of glucose,
egg
albumen, and other substances including potassium ions did not produce
this
squeezing or "narrowing" response.
These features present problems to evolutionists
attempting to square
the origin of the traps with the neo-Darwinian model. The plant
must have
had a full-formed trapping mechanism complete with trigger hairs, digestive
glands, living bars, and action potential response before insects of
any
type could be incarcerated. The trap would also have to have the capability
of responding to the sodium ions (from the haemolymph) secreted by
the dying
insects so that proper "narrowing" or squeezing and digestion would
occur.
A reasonable creationist alternative to evolutionary
proposals about
this plant is that a Designer formed these systems and balanced the
interactions between body chemistry of insects and the Venus flytrap
plant.
I find it interesting that generally carnivorous
plants grow in areas
where there is a lack of nitrogen. It is also interesting and common
knowledge that these plants can grow, produce flowers, set seed, and
fully
propogate without ever eating insects. It may be, however, that insect
food
is required under certain conditions of nitrogen nutrition in the soil.
Has
any creationist research been done in this regards?
Also of interest is that the center part of the
Venus-flytrap is deeply
stained a beautiful red color. Has any research been conducted to see
if
perhaps this pattern of coloration plays a role in attracting insects?
Mark Stewart