The
slime mold continues to surprise and impress. Note here that this
particular species is a cell one foot across. It is full of
individual nuclei. Now imagine this cell filling itself up with
methane. It quickly becomes a huge bubble of methane that will
naturally rise in the atmosphere. Thus we have physical confirmation
of the plausibility of methane filled slime molds tripping to the
stratosphere.
The
actual transition remains unobserved and unremarked but the
astonishing size such cells can reach almost make it inevitable.
This also makes real sense out of the early claim that 'UFOs' were
swamp gas which makes absolutely no sense without this mechanism.
One presumes an early investigator got in there on the ground and
somehow made the connections.
From
this item, the idea of memory is pretty generous.
Puddles of Goo?
Brainless Slime Molds Have Memories
Charles Choi,
LiveScience Contributor
08 October 2012
4
Even without a brain,
a slime mold can essentially remember where it's been, helping it
navigate past complex obstacles, much like modern robots, researchers
say.
These findings reveal
how ancient organisms could solve certain problems well before
complex brains evolved, scientists added.
4
Slime molds were once
thought to be a kind of fungus, but later work revealed that these
puddles of goo are part of a motley group of microbes known as
protists. The yellow slime mold the investigators studied, Physarum
polycephalum, is actually a giant single cell up to more than 1
square foot (900 square centimeters) in size with up to several
million identical cell nuclei inside.
"For a single-celled organism, it has continually surprised
researchers with its abilities, such as solving mazes, anticipating
periodic events, and even making irrational decisions like we do,"
said researcher Chris Reid, a complex systems biologist at the
University of Sydney in Australia. "It is truly a remarkable
creature that is redefining
our
notions of intelligence."
our
notions of intelligence."
This slime mold leaves
a thick mat of translucent slime behind it as it moves, ooze that
Physarum later avoids. As such, the researchers thought
the slime mold might use this gel trail as a kind of
memory.
"The key
misunderstanding might be that slime mold has a memory like we do,"
Reid told LiveScience. "I can't stress enough that the slime
mold is incapable of creating, storing or recalling memories like
ours, because it does not have a brain, or even neurons."
[10 Odd Facts About the Brain]
"Rather, our
definition of memory is very broad — the storage and retrieval of
information relating to past events," Reid said.The study
authors reasoned this slime mold uses its trail as a reminder of
where it has been, leading Reid to liken its ooze "to Hansel and
Gretel's bread trail, or Ariadne's thread used by Theseus to escape
the Minotaur's labyrinth in Greek mythology."
To explore their idea,
the scientists challenged the slime mold with a test in which the
organism had to reach a sugary meal it could sense that was located
behind a U-shaped barrier. Similar problems are common tests of
robots to see if they can autonomously navigate their way past
complex obstacles to reach desired goals.
In some experiments,
the slime mold could detect its own gel trail. In others, the
researchers covered the area with extra gel that masked the slime
mold's own trail.
When Physarum was
able to detect its own trail, it reached the food about three times
more often and about 30 percent faster, on average. Slime molds
blinded to their own trails spent almost 10 times longer pointlessly
re-exploring areas they had already visited, Reid said.
"This is the
first time anyone has demonstrated a spatial memory system in
a creature without a brain, and the first piece of evidence
that supports the previously untested theory that an externalized
memory could have been used by primitive organisms in the distant
past to solve problems tackled by complex brains like ours today,"
Reid added.
Reid and his
colleagues plan to continue investigating these trails of slime.
"There could be a
whole wealth of information that the slime mold is leaving behind in
the slime to communicate with its future self, or even other slime
molds that happen to be around," Reid said.
The scientists
detailed their findings online Oct. 8 in the journal Proceedings of
the National Academy of Sciences.
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