Our world
THE A MAZE -ING BLOB
If you go down to the woods today, there’s something you almost certainly
won’t see. Not because it isn’t there, but because it likes to hide.
If you’re careful and look under
leaves, or moss or twigs, you might
be lucky enough to find one. It might
be yellow, it might be orange, some
of them are bright pink but no matter
how you look at them, they all look a
bit like a blob of bogies. (YUCK, I’m
sure I didn’t say you could talk about
bogies, ed.)
But this little blob is alive and it has a
few things to teach us.
The blob is something very special.
It’s not an animal, it’s not a plant and
it’s not even a fungus, it’s a slime
mould, and it likes to be just a little
bit different. Every living thing is
made up of cells. In your body there
are around 37 million million of them.
You have loads of different types, but
a slime mould – no matter how big it
gets – is made up of just one cell. We
call a giant cell like this a
plasmodium. If you watch one it
doesn’t look like it’s doing much.
They do move, it’s just that their top
speed is just a centimetre an hour –
slower even than a snail.
AMAZING!
For years slime moulds were just a
curiosity, some people kept them as
pets, living in petri dishes and fed on
porridge oats. Then in 2000,
scientists in Japan discovered that if
you put one in a maze it can find the
shortest path to cross it. Not only
that, but the way slime solves the
maze is better than any computer
program.
So how does a single cell solve such
a complicated puzzle? If you
dropped one of us in a maze, we’d
explore it using our eyes to look
around and using our brain to
remember where we’ve been. Slime
is a single cell; it has no eyes. It can
feel its way around, but that
doesn’t explain how it knows if it’s
been somewhere before – how can a
single cell have memory?
If you were forgetful, you might write
yourself a note and stick it to the
fridge door as a reminder. That’s sort
of what a slime mould does.
Everywhere it goes it leaves a chemical
trail, and in that trail it leaves messages
telling it where it’s been and whether
there’s any food over there. Slime
moulds keep their memory outside
their bodies.
And it’s not just mazes they can solve
like this. In 2010 another group of
THE LIFE AND TIMES OF A SLIME MOULD
1 Slime moulds hatch
from spores…
2 …into a microscopic cell that
looks like an amoeba…
In the wild, slime moulds feed on
bacteria and fungi, they spread their
bodies out and explore. When they
find a piece of food, they wrap
themselves around it and sta