If you're seeing this message, it means we're having trouble loading external resources on our website.

If you're behind a web filter, please make sure that the domains *.kastatic.org and *.kasandbox.org are unblocked.

Main content

What is a biodiversity hotspot?

What a biodiversity hotspot is, and why these locations are important to preserve. Video by California Academy of Sciences. Created by California Academy of Sciences.

Want to join the conversation?

  • leafers ultimate style avatar for user EdSheeranFan16
    I understand that we're protecting life for future generations, but why should we be so selfish as to be able to visit and see these animals? I mean, we're the reason they're in danger, so why should we be able to have interaction with them?
    (5 votes)
    Default Khan Academy avatar avatar for user
    • old spice man green style avatar for user Leonardo DiCaprio
      The reason why is because of vast population with pollution in particular typically always interact with these animals somewhat. We have a responsibility to protect them by limiting out influence on them and focusing our resources on them to help the endangered species. Biodiversity is important to us and the animals/plants. We are doing for both, not only for them. I think that answers your question.
      (5 votes)
  • leaf green style avatar for user Archie Jerome Maramag
    Who determined 1,500 endemic species of plants? And why 1,500? Why not 100, or 2000?
    (4 votes)
    Default Khan Academy avatar avatar for user
    • spunky sam blue style avatar for user ave
      (This reply is years late and I apologize) There are simply too many species on the planet for us to designate an area as a hotspot with only 100 endemic species, which is why the number is so relatively high. As for why the number isn't higher, I'm willing to assume that once you get much higher than 1500, there just aren't any locations you can designate as hotspots anymore, considering that places with 1500 endemic species still only make up less than three percent of the surface. And as for 'why plants?', as stated in the video, plants make up the base of the food chain and life cannot exist without them, so where there is diversity in plants there is often diversity in animals.
      (3 votes)
  • male robot hal style avatar for user _NievesJacob
    At https://www.youtube.com/watch?v=RaQBaVeEbW8#t=102 it says this: >70% LOST. How come the > is pointing away from the 70? ( I know about this stuff, but this one is a bit confusing. For example, 900 > 812)
    (2 votes)
    Default Khan Academy avatar avatar for user
  • blobby green style avatar for user David Rosenfeld
    How did you arrive at >70% of habitat destruction as the border line for hotspots? And how do you measure it? Seems like an awfully high bar. Why not designate, say, >50%? Over 50% would still seem like a potential tipping point.
    (3 votes)
    Default Khan Academy avatar avatar for user
  • leaf green style avatar for user vidyaovya06
    what is heridity
    (1 vote)
    Default Khan Academy avatar avatar for user
  • blobby green style avatar for user Jahsiem836
    Can people die from this?
    (1 vote)
    Default Khan Academy avatar avatar for user
    • piceratops ultimate style avatar for user Sarath Badithala
      There is a possibility because as biodiversity dies off there will be a chance for the pollinators to be affected too and if there are no pollinators especially bees then there will be no food for humans to eat so gradually humans will die if technology doesn't help in one way or another
      (3 votes)
  • mr pink red style avatar for user Katherine Nassiwa
    What is chromosome non-disjunction?
    (2 votes)
    Default Khan Academy avatar avatar for user
    • male robot donald style avatar for user Aaron Ghosh
      Nondisjunction is the failure of homologous chromosomes or sister chromatids to separate properly during cell division. There are three forms of nondisjunction: failure of a pair of homologous chromosomes to separate in meiosis I, failure of sister chromatids to separate during meiosis II, and failure of sister chromatids to separate during mitosis. Nondisjunction results in daughter cells with abnormal chromosome numbers (aneuploidy).
      (1 vote)
  • aqualine ultimate style avatar for user Ralph Stokes
    Whoa there. at - If eco systems are connected interactions of organisms as per the first video then the whole earth can be seen as one eco system. As previously shown everything is interacting with everything so I do not see how "saving" a few places will save a dying eco-system as there will always be external pressures which will lead to inevitable decline of the global eco-system. You have already presented evidence in the previous videos which shows that simply protecting a few "eco systems" won't be enough by illustrating the complex interactions of an eco system and how eco systems arise from eco systems - Take the whale in the last video - whales roam from the north to south pole and as shown form a vital part of the ocean eco system therefore you can't solve the decline in wales by only protecting a little area of ocean, you need to protect the entire ocean in order to make sure the conditions for the whale are optimum as it not only lives all over the globe but its food comes from many many different areas. The reasoning at the very beginning of this video makes no sense at all from an ecological point of view. The way it is presented here, it seems more like the main thing we are trying to protect here is a broken economic system that does't care for the environment and that system takes priority over the eco system and biodiversity? Dollars are not resources, resources are resources and If you come at this problem using the same kind of thinking that created the problem (i.e. deregulated capitalism) then you are not going to be able solve the problem.
    (2 votes)
    Default Khan Academy avatar avatar for user
  • aqualine ultimate style avatar for user Robert M
    When the map showed, why is it North America had none?Central and South did, but not north.
    (1 vote)
    Default Khan Academy avatar avatar for user
  • leafers tree style avatar for user natasharomanov
    Thanks for your effort.How can I be more like you
    (1 vote)
    Default Khan Academy avatar avatar for user

Video transcript

- [Instructor] What we're gonna talk about right now is something called a biodiversity hotspot. How do you figure out what the places are on earth that deserve our special focus, that deserve attention that they need to protect them for future generations? It's obvious that the earth is in trouble and we can't save the entire planet all at once. We need to have a focus. We can't do triage on an entire planet. We've limited resource. We have limited time. We're running out of time to protect many of these places. So what are the criteria that we use to try and figure out what those hotspots really are that need that special attention and protection? Back in 1988, ancient history to some of us and in fact might be pre-history to others there was a scientist by the name of Norman Myers who wrote a really important paper that analyzed different types of geological, climatological and uniqueness criteria to come up with concept of a hotspot. Scientists who look at this problem and decided eventually that there really were two main criteria that were gonna lead to what Conservation International now recognizes as a biodiversity hotspot. One criterion was that there had to be at least 1500 endemic species of plants. We'll get back to the idea of endemism in a moment. There also had to be an additional factor that made the area unique and deserving of our focus. There had to be more than 70% of the original habitat already lost which highlighted the need to designate this place as a hotspot. Well why plants? Plants, particularly in terrestrial environments are crucial. Animals go where the plants are. Plants are the primary producers. They're at the base of food webs. Life attracts other life and it depends on other life. Now let's get back to that idea of endemism. An endemic species is a species that's found in a certain area and nowhere else on earth. In other words, endemism is a measure of how unique and irreplaceable something is. An example of an endemic organism that resonates with people, people love tortoises. If you think about the Galapagos Islands for example, most islands have their own special type of tortoise. It lives there, and nowhere else. So if something happens to wipe out the tortoises on that island, those tortoises are gone forever. They're not found anyplace else. They were irreplaceable. At the moment Conservation International formally recognizes 34 biodiversity hotspot areas on earth. The interesting thing about this is that less than three percent of the earth's land surface area is represented by these hotspots. So we're talking about some very, very special places indeed. There are other ways to think about these special places on earth besides hotspots. Some of these concepts are used to help recognize larger geographical units of land and water that have unique assemblages of species or distinct environmental conditions that make them worthy of our special attention. I think it's really important that we recognize that the hotspot idea is much more than a conservation tool. It's actually become a powerful scientific tool. Because hotspots are a blood pressure cuff for planet Earth. You can go back and keep measuring the effects on these different places due to human activity or environmental change of various kinds and go through the science of measuring the pressure on biodiversity. In a sense, hotspots are almost like avatars. They're like representatives for other endangered areas on the planet that might not necessarily meet this special criteria of 1500 endemic species of plants and more than 70% of the original habitat lost and yet they are still obviously critical and important places for lots of organisms to live. You need to think about hotspots as a network of places on Earth that are interconnected. Not just single units that protect small pieces of biodiversity but that help preserve biodiversity in a great many other habitats and other hotspots as well. And lots of conservation organizations, government agencies and even concerned people like all of us can use these hotspots to better help direct the resources to the places that require our greatest attention. Above all, we need to remember one overriding principle. That we focus on protecting the highest number of species that we can. Especially the ones that are most threatened. That's what this hotspot concept is trying to get to. We want to enhance our ability to protect species richness. That way, we can boost the stability and resilience of ecosystems. So I think that for me these hotspots really do carry that special signal and are really worthy of the special effort that's been developed over the last few decades to monitor to them, to provide the good, solid science that helps us not just to define them but to monitor and promote their health down the road and to employ those concepts to draw people in, to develop that people power that's really necessary to move forward with the protection of life on Earth.