Hi. It's Paul Andersen. And this is disciplinary core idea LS4D. This
is the last life science disciplinary core idea. And in this one we talk about us. We
talk about humans and our impacts on biodiversity. Biodiversity is pretty simple to define. It's
simply the variety of life that we have on our planet. And why is that important? We
need our planet for our resources. In other words we get natural resources from our planet.
It's as simple as the food we eat, the water we drink. The energy we require. And if we
get sick, it's the medicine that we require. But there are bigger ecosystem services that
life, that the earth serves. Number one it stabilizes our climate. And water is important
in doing that. It breaks down material when it's dead. And also pollination we find is
incredibly important. Especially when we're starting to create enough food for the people
on our planet. And so what is biodiversity? Biodiversity is simply the variety of life
on our planet. And it's really a fairly recently defined term. And so that variety could be
genetic variety, species variety or even ecosystem variety. And so an example of genetic variety,
as we look through the oceans right now, there are ships that are moving around the ocean.
They're sampling DNA from the ocean. And we're finding and discovering this great wealth
of variety, genetic variety in the oceans. We used to think the plankton and viruses
were fairly simple. And we're finding this incredible complexity out there. It could
also be species variety. So if we were to go to a rain forest we're going to find so
many species out in the rain forest. This is simply some of the fruits that are found
in the canopy of one area of the rainforest. And we also have all of these different ecosystems
on our planet. And so that's variety as well. And so the frther of biodiversity, his name
is E.O. Wilson and really coined the term. And what we said and why he alerted us to
that is that humans are having huge impacts on biodiversity. And that's eventually going
to cause serious financial impacts on humans as well. And a good way when was asked about
this in the 1980s, a good way to remember those impacts, he came up with this mnemonic
and its HIPPO. And so how are humans impacting biodiversity on our planet? We're destroying
habitat. We can see that in the rain forest. Invasive species. In other words we're moving
species from one area to an area where they never were. And a great example of that would
be the brown tree snakes in Guam. Pollution. Be it water pollution or air pollution is
changing biodiversity. We're getting overpopulation of humans. Or population is just getting larger
and larger and larger. And that's putting more demands on planet earth. And then finally
over explotation. So that could be over harvesting of fish for example, are having impacts. And
so when he was talking about this in the 1980s, this was his list. What is one big thing that
we've added to that list since the 1980s? That would be climate change. In other words
we're getting increases in green house gases. That's changing the temperature on our planet.
And it's having huge impacts on the biodiversity. So how do you teach this in schools? What's
the teaching progression? Well in the lower elementary grades you want to start talking
about this idea of variety. Or how many different species we have in an area. And so could you
give your students a picture like this and ask them to identify all the species of plants
and animals that you might see? In this picture? Or in this picture? Or in this picture? That's
the first thing you want to talk about. This idea that there's a great variety out there.
And better than just showing them a picture is get them out there and start analyzing
the area around them. As we move into the upper elementary grades we want to start talking
about these populations of organisms or group of organisms that look the same. And how they
interact with their habitat. So here we have a population of rabbits. And how are they
going to interact with their habitat? And what's going to happen if we get changes in
that habitat? What's going to happen to the population over time. As we move into middle
school we really want to define biodiversity as simply variety. And it could be genetic
variety. Species variety. Or ecosystems variety. And we also want to start talking about humans
and how humans are having impacts on the biodiversity of our planet. And there's huge amounts of
statistics out there on that. Why is that important? Well, it's bad to decrease the
biodiversity because they're not going to come back. But also you want to put forward
this idea that they're are going to be financial impacts on organisms. And financial impacts
on humans just because we rely on them for our natural resources. As we move into high
school we want to start talking about the variety of life on our planet. And how did
it come to be? How did we get this great biodiversity? Well it's through speciation. The idea that
one species forms two. And those form four. And those form eight. In other words on this
great tree of life, the only way we can get variety is through speciation. One species
becoming two. Likewise, how do we get rid of species? That's through extinction. So
one of these lines ending is through extinction. And that's permanent. Once we get rid of that
biodiversity, once we get rid of that species, it's not going to come back. And so it's important
that students understand that. And this idea that we're having huge impacts on the habitat,
invasive species, pollution, population, overexploitation. But the big thing that you're students are
going to face in their life is this idea of climate change. We're making huge changes
to the climate which is going to decrease biodiversity. Look no further than into the
rain forest or on the coral reefs on our planet. We're seeing huge impacts on species diversity.
And so those are eventually going to have financial impacts. And so some people as we
look through the history of life, they talk about five great extinctions. And then they're
now talking about the sixth great extinction. And that's due to impacts that humans have
had. But the nice thing is once we understand it then we can make changes to kind of reverse
that process. And so that's us. That's humans and our impact on biodiversity. And I hope
that was helpful.