When you think of mass extinctions you probably
think DINOSAURS!!!
Which I mean, that’s fair.
Cuz, ya know, dinosaurs.
But the greatest extinction event of all time
wasn’t the dinosaurs at all.
About 250 million years ago something caused
even more species to die out -- in an event
called the end-Permian extinction, also known
by its much cheerier name -- the great dying.
The Great Dying took out 96 percent of marine
species and 70 percent of all land-animals.
Yeah.
Scientists have been searching for the exact
cause of this mysterious mass extinction for
decades, but most scenarios they’ve come
up with have been, well, less than satisfying.
However, a researcher at UC Berkeley is on
the case, and he might be onto something.
The most convincing theory so far involves
the large scale volcanism of the Siberian
Traps that happened around the same time as
the End-Permian extinction.
For those playing the home game, that’s
at the end… of the Permian Era.
The eruptions exploded 300,000 years before
the End-Permian extinction, but were active
for hundreds of thousands of years... even
after.
They oozed lava and spewed ash all over the
place.
This would’ve caused a host of issues like
global warming and localized acid rain.
But how did volcanoes in Siberia manage to
wipe out life across the whole planet?
To add to the mystery, the end-Permian fossil
record shows that a global decline of forests
at this time was coupled with mutated pollen.
Something was making it impossible for plants
to reproduce, hmmm.
It’s been proposed that the volcanic gases
from the Siberian Traps could’ve severely
compromised Earth’s ozone layer -- exposing
life on earth to extremely high levels of
UV-B radiation.
Scientists think this could’ve damaged the
plants, potentially destroying the food chain
from the bottom up.
This is where UC Berkeley Researcher, Jeffrey
Benca, comes in.
To test this theory, he took mini pine trees,
and put them in an extinction chamber.
Inside they were exposed to extreme amounts
of UV-B, akin to what would’ve been experienced
before the Great Dying.
Lo-and-behold-- the trees made malformed pollen
and became sterile!
What’s even crazier though, is four of the
five greatest extinctions on earth--- including
the dinosaurs-- were accompanied by large
scale volcanic events, which are often associated
with warming global temperatures, acid rain,
and you guessed it: ozone layer depletion.
It’s a little too early to say if this new
finding helps explain other extinctions.
But it is kinda crazy that Earth’s worst
extinctions weren’t caused by giant asteroids
or hellfires, but good old fashioned climate
change and ozone depletion, ain’t it?
If we keep at it, we might just bump The Great
dying out of first place.
Do you think we could get a trophy for that?
If you’re still worried about the ozone
layer, you might want to watch this video
about how scientists stood up to power and
saved it.
BTW while researching this we found: those
volcanic eruptions from Siberia?
They oozed enough material to cover a region
the size of the United States in magma -- a
KILOMETER DEEP. Cool. Thanks for watching.
