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Thursday, October 23, 2014
Thousands of Mysterious Circles
Let us make life simple. we are looking at a biological phenomena capable of intelligent design. The rings never accidentally overlap. It is definitely something ants can do. Their reason remains obscure but at least we have a unique ant and a target environment. We need to find a barren comparable and add an ant colony. It is fair to say that they were right the first time and likely need to do observation without sunlight. It must be the sand ant. Can it be harvesting something here or is it using a toxin to stop competition? Otherwise we have a neat confounding desert display.
The Namibia desert is decorated by one of nature’s greatest enigmas, a huge pattern of thousands of mysterious circles
Viewed from the skies, the Namibian desert looks like the surface of
a wild and desolate planet. There are no obvious plants, and thousands
of tiny craters dot the red barren earth. But zoom in a little closer
and a different picture emerges: patches of green appear, along with the
occasional tree, and, eventually, perfect rings of tall, sometimes
lush, grass come into focus, each one enclosing a plate of bare-hollowed
These grass-ringed patches are the fairy circles of
Namibia. For centuries they’ve entranced the local bushmen, the Himba.
One oral myth says the circles are the footprints of the gods; another
that a dragon living beneath the earth’s crust breathes fiery bubbles
which, when they hit the surface, burn the vegetation into the
But the circles haven’t just confused the
Himba. Despite decades of investigation, and a multitude of theories,
scientists still haven’t come up with a definitive explanation for their
existence. To this day, the circles remain one of nature’s greatest
A thousand unblinking eyes
the fairy circles wouldn’t have been able to guard their secrets so
successfully if they hadn’t been so concentrated in a region referred to
as “The land God made in anger.” The circles occur in millions in a
band where the arid grasslands transition to desert, a 1,800km-long
strip extending southward from Angola to the Northwestern Cape province
of South Africa. Most of them, however, flank the red sands of the Namib
desert, a remote and harsh environment.
The circles appear to be regularly spaced (credit: Stephan Getzin)
Scattered across the landscape, never overlapping, the
circles gaze silently up at the sun like a thousand unblinking eyes,
oblivious to the harshness of their surroundings. A tall ring of grass
surrounds the barren centres, which can measure between two and 20
metres in diameter. The lush periphery of each dish stands at knee
height, dwarfing the scrubby grasses between the circles, seemingly
standing guard to protect them from incoming vegetation.
There is a tremendous sense of excitement that there is something really interesting going on
are a few key things that any science theory has to explain about fairy
circles,” says Michael Cramer, a plant physiologist at the University
of Cape Town, South Africa. “Why are they circular and barren and why
are they regularly spaced from each other?”
But since the 1970s,
when researchers first started investigating the phenomenon, no single
theory has yet managed to do that. At least not to the satisfaction of
the scientific community. But this failure is not for want of trying, or desire.
is a tremendous sense of excitement that there is something really
interesting going on and we want to know what that is,” says Professor
Don Cowan, director of the Centre for Microbial Ecology and Genomics at
the University of Pretoria, South Africa. “It is a desire to understand
the system. What is going there? What is happening?”
Fairies run rings around scientists
are really neat places, these little clean patches,” says Walter
Tschinkel, a biologist at Florida State University. “They are like
little satellite dishes.” When Tschinkel, the biologist from Florida,
first saw the fairy circles on a visit to the NamibRand Nature Reserve
in southwestern Namibia, he knew right away what was causing them. "I
looked at them and thought ‘this has to be termites,’” Tschinkel says.
“It is the sort of things termites do.”
Tschinkel dug for termites
in one or two circles and returned in 2007 to investigate, and
hopefully prove, his hypothesis. “It took us about three days to
establish, without a doubt, that termites were absolutely nothing to do
with this,” Tschinkel says.
Tschinkel’s theory proved to be just
one of the many to hit the Namibian dust. Scientists have ruled out
poisoning from toxic indigenous plants, milk bushes that produce toxic
latex, and also contamination from radioactive materials. They have also
rejected the idea that the ostriches created the circles by bathing in
Ostriches were once thought to create the fairy circles (credit: Frank Vassen CCby2.0)
Some theories are still holding strong though, and Cowan
jokes that each scientist sees the solution in terms of their own
particular area of expertise: the insect biologists think the circles
are created by ants or termites, the plant physiologists think it’s
grasses, and the chemists think it’s gases. Cowan, a microbial
ecologist, proves no exception.
“Once we saw them, we immediately
thought, ‘it has got to be microbial ecology,’” Cowan says, meaning, in
layman’s terms, that means he believes that microorganisms have been
killing the plants inside the circle.
The fact that the circles
are round, start off small and grow large is entirely compatible with
the presence of a pathogenic organism, such as a fungus, Cowan says.
Fungal strands, or mycelium, would spread outward radially, infecting
the roots of plants and causing them to die. Once the fungus establishes
itself in the circle it infects new grass seeds preventing them from
growing, creating the barren interior.
“It is just a hypothesis,” Cowan says. But it’s more compatible with the evidence than many other theories, he adds.
It is like panning for gold. Once in a while you find a little flake or a nugget and sometimes it is fool's gold.
theory is closer to the folklore; a team of chemists from the
University of Pretoria propose that gas released from underground may be
killing off the plants in the circular patches. They just don’t suggest
this gas comes from the mouth of an underground dragon.
scientists worked out this theory when they collected soil samples from
inside the fairy circles and planted seeds inside them. The seeds didn’t
last for long, and neither did seeds planted directly in the centres
themselves. The bare soil, the scientists concluded, provides the real
clues. Chemical analysis revealed that natural gas seeping to the
surface could be killing the plants. Once the gas finds an outlet it
spreads radially outward in a spherical shape destroying grasses in a
near perfect circle.
However, yet another recent theory proposes
that grasses competing for water and nutrients - limited resources in
the Namib desert - create the circles, explaining why they never
overlap. When Cramer examined precipitation levels and seasonal
temperatures, he found that the occurrence of fairy circles appears to
be restricted to particularly arid zones right at the transition from
grassland to desert regions.
Inside a fairy circle, nothing seems to grow (credit: Stephan Getzin)
Go west into more arid regions and the circles
disappear, go east into the wetter mountains and they vanish. “So it is a
very narrow band in Namibia where the conditions are just right,”
Cramer says. In these regions, where both rainfall and nutrient
levels are low, grasses have to compete for resources. Hardier grasses
suck up all the water and nutrients leaving the neighbouring vegetation
to die. The gap between vegetation gets larger until eventually water
and nutrients pool and collect in the centre like an oasis. Then, larger
grasses grow around the pool, sucking out the water and creating a
Tschinkel believes that this theory accounts for all
the characteristics of fairy circles, but since his first visit he has
been busy testing out theories. He’s added zinc to the fairy circles and
replaced the soil with other fertile soil only to find the same results
as the Pretoria chemists: nothing grows in the circles.
like panning for gold,” Tschinkel says. “Once in a while you find a
little flake or a nugget and sometimes it is fool's gold.”
Mystery solved. Or not?
there were an award for the time spent examining fairy circles, the
prize would surely go to Norbert Jürgens, an ecologist at the University
of Hamburg in Germany. By 2013, Jürgens had completed 40 field trips
and sampled about 1200 fairy circles, testing the soil and noting the
vegetation and organisms present.
Jürgens found only one organism
lay within the circle boundaries, in nearly all the circles. And it was
the type of animal originally suspected by Tschinkel; a termite,
specifically the sand termite Psammotermes allocerus.
answer to the criminal question: Who did it?” Jürgens says. “There was
only one suspect at each crime site. That was the sand termite.”
We’ve had analysis of the soil in labs and we’ve had people digging in the soil but neither has solved the mystery so far
soil-living termites feed on the roots of plants killing them, and
then, because no vegetation sucks up the rainwater, water pools below
the sandy soil, Jürgens says. This soil water supply allowed the
termites to survive during the dry season and also helped the grasses on
the periphery of the circle to thrive.
Jürgens published his
findings and theory in the prestigious journal Science in 2013 and the
ensuing media fanfare dubbed the mystery as “solved.”
But other scientists aren’t so sure.
The circles are concentrated within a 1,800km-long strip of land (credit: Stephan Getzin)
“It is the classic mistake of confusing correlation with
causation,” Tschinkel says. “There was a high correlation of sand
termites in fairy circles but that is not evidence that they are
The termite theory cannot explain many of the traits of
fairy circles, Tschinkel says, including that the circles have a
perimeter of tall grass and reside only on sandy soils in a certain
range of rainfall.
Other researchers question the theory on
different grounds, many unable to find termites consistently in the
circles. "The termites are just not there," Cramer says.
The circles compete with one another and space themselves apart from the circles around them.
the skeptics is Stephan Getzin, an ecologist from the Helmholtz Centre
for Environmental Research, in Leipzig, Germany. As an undergraduate in
the 1990s, Getzin had investigated the termite theory but he’d convinced
himself that, not only were termites not the cause, but that scientists
needed to take a different approach to the problem.
analysis of the soil in labs and we’ve had people digging in the soil
but neither has solved the mystery so far,” Getzin says. “Field studies
seem unable to solve the problem at this moment.”
And the approach that Getzin took cast a whole new perspective on the puzzle.
Fairies dancing in formation
had looked underground for gas and dug in the soil for termites and
microbes but Getzin wanted a bird’s eye view of the challenge. For that
he looked at multiple Near InfraRed orthophotos - aerial images that
provide an exact geometrical perspective, similar to a map.
these images Getzin closely inspected not the circles themselves, but
the way they lay across the landscape. And he stumbled across a hitherto
unknown feature of fairy circles: they dance in formation.
Are scientists any closer to solving the enigma?
Instead of being simply scattered like a collection of
dropped coins, the circles lie regularly spaced from one another.
Moreover, this patterning remains the same across the landscape.
“It’s a very consistent regular pattern,” Getzin says, “and it is very homogenous at large spatial scales.”
regular spacing isn’t so unusual in nature. In other regions of Africa,
tiger bush - alternating bands of shrubs and bare earth - run parallel
to the contour lines of hillsides, in a marked striped pattern. In
Australia, burette-like clumps of spinifex grass dot the desert - like
fatter, less elegant cousins of fairy circles.
They almost function like an organism
these phenomena are caused by arid conditions. When water and nutrients
are scarce, plants compete and “organise” themselves sufficiently far
from other plants in an arrangement that best conserves resources.
from these examples, Getzin proposes a similar mechanism lies behind
the shape and regularity of the fairy circles. It’s an answer that
agrees with Cramer’s competing grass theory.
“The circles compete
with one another and space themselves apart from the circles around
them,” Cramer says. “They almost function like an organism.”
these patterns over such large scales requires very consistent
conditions - like those in the Namib desert, Cramer says. “The park I
work in is a sand plain of about 25km across and I think you'd be hard
pressed to find any variation across that at all,” Cramer says.
“Nutritionally, hydrologically, topologically it is very uniform. “
finding also calls into question other theories. “Based on all the
knowledge that is currently existing those patterns cannot be caused by
social insects or gas leakage,” Getzin says.
Observing the circles from the air may provide answers (credit: Stephan Getzin)
So is this finally the end of the mystery?
is cautious. “What we have done is reopened the whole discussion because
we can say with confidence that the termite hypothesis is very
unlikely,” he says.
Getzin plans to get funding to have an
unmanned aerial vehicle (UAV) fly over the circles in the NamibRand
reserve every month. Swooping low, the UAV could record the landscape in
greater detail than previously possible.
Such a perspective could reveal other, previously unknown secrets of the circles.
“I’m sure this is not the end of the story,” Getzin says.