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  • 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.

Hi. It's Paul Andersen. And this is disciplinary core idea LS4D. This

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B1 中級

LS4D--人類與生物多樣性 (LS4D - Humans and Biodiversity)

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    阿多賓 發佈於 2021 年 01 月 14 日
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