Save the rainforest!
And the animals!
And the ecosystems!
And also save me a chocolate bar cause I have a feeling this mass extinction thing is gonna
be rough.
Hey folks, Laci Green here for DNews.
In the 3.5 billion years that earth has been hosting evolving species, there have been
5 “mass extinctions” where a large percentage of species die off.
The most famous of course is the mass extinction that killed off the dinosaurs 66 million years
ago.
The Cretaceous Extinction Event killed off about 75% of the species on earth, but the
most deadly was the Permian-Triassic Extinction. 90% of species went KAPUT.
In new publications in the journal Science, scientists are saying that it’s beginning
to look like we are on the brink of the sixth mass extinction, an era researchers are calling
“Anthropocene Defaunation”, meaning human-caused animal decline.
Currently we’re losing about 27,000 species every year JUST because of tropical rainforests
being reduced.
Animals are dying off in large numbers - for instance, the invertebrates like butterflies,
beetles and spiders, have declined 45% in 35 years.
During that same 35 years, the human population has DOUBLED.
Amongst vertebrate species, anywhere from 16-33% of them are globally endangered, and
the highest risk are a group called “megafauna”.
The big ones.
Rhinocerous, giraffes, elephants, polar bears.
This group is declining at a rate that matches extinctions in the past and it’s being attributed
to shrinking habitats (when they need a lot more space to survive), climate change, as
well as human hunting.
It’s estimated that humans have sped up the rate of extinction by 1000x.
What does this mean for us slash why does it matter?
Well, for one, these big animals are predators.
An experiment done in Kenya where they isolated an area without any megafauna saw the number
of rodents double.
Two, when the number of rodents double, so do the number of parasites they carry that
cause diseases.
One of the researchers at Stanford explains that without megafauna, there is more disease
that can threaten humans.
Three, it matters because biodiversity ensures the health of our ecosystems and thusly...human
survival.
Not just because of the disease threat, but because of we need fertile soil to grow crops.
We also need pollination of our crops.
No fertile soil or pollination equals no food.
Healthy ecosystems also clean and recirculate water and air, and they provide the resources
necessary to produce pharmaceuticals.
Some biologists think that with our habits, we’re on track toward human extinction in
later centuries.
Others think that we’ll be thinned out, but we will survive.
We are the most dominant species in history, after all.
In the case of a mass extinction, it would only take aroundddddd….200,000 generations
of humans to get back to the amount of biodiversity we currently enjoy.
Thanks for watching DNews folks.
We’ll see you next time.