TED Conversations

Lucy Irons


This conversation is closed.

Are you concerned about the spread of invasive species?

Invasive species are non-native species that have a negative impact on their introduced environment. Invasive species are a huge issue not only due to their environmental impacts, but their economic ones as well. According to the National Invasive Species Information Center, there are currently about 50,000 invasive species in the United States alone that cost over $138 billion annually to manage. invasive species have a number of distinctive traits, including A general diet, large amounts of genetic variation, the ability to survive in a wide range of climates, a continuous breeding season, and the production of many offspring every year. What role do these versatile organisms have in a world where many species and ecosystems potentially lack the diversity required to survive rapid changes in their environment? Is it possible that, in the face of global climate change and biodiversity loss, invasive species can contribute something positive to biological systems?


Showing single comment thread. View the full conversation.

  • Mar 16 2012: When I think about invasive species I think about a harmful species that has a huge negative effect on its ecosystem and surrounding ecosystems. This is true, but I also think that the degree of negativity of the invasive species needs to be consider in answering this question. An invasive species that does not kill everything it comes into contact with is going to be less of a threat and could potentially be a benefit when looking at the adaptation that is necessary with the overall loss of biodiversity and climate change in today's world. In this case we could let evolution run its course and only mediate when problems arise. On the other hand invasive species that has negative effects that would wipe out an entire ecosystem would not be beneficial to us and would definitely need to be eradicated. So overall, I think that to determine whether or not we should be concerned about an invasive species lies within the degree of detrimental effects that the invasive species has on the ecosystem.
    • thumb
      Mar 16 2012: I totally agree that there are different degrees of invasiveness. An interesting question that I think is relevant both in biology and in global politics at the moment, is whether or not we, as humans, have the right or responsibility to "fix" things that we deem as problems with our environment? Is it about what's beneficial to US or about what's beneficial to the planet? Humans are special in that we can think outside of our own survival and try to look at what would make ecosystems better as a whole and sometimes I think we'll see that those two goals oppose each other.
      • Mar 17 2012: Here's a good example of humans attempting to "fix" something: http://www.youtube.com/watch?v=48_X6gA8S18
        Because the cane toad has already established and is hard to remove these folks have targeted one of the negative effects that it has and is trying to alleviate it. Some may say that they are unethically interfering with the quoll's behavioral evolution, but I believe it can actually be for the better because we have the capability to recognize if things are heading in a bad direction and we can "nudge" other species towards different evolutionary paths.
        • Mar 17 2012: Much can be learned in the case of the introduction of the cane toad. When researchers developed a plan to protect sugar cane plantations from cane beetles, they failed to look at seemingly obvious factors, such as where the biological range of the cane toad actually is. They implemented the plan thinking that the toad would specialize in the beetle on the sugar plantations without realizing soon enough that the habitat is unsuitable for amphibians. It was too hot and dry in the fields, and the cane toads preferred the shaded regions of the ecosystem. They effectively invaded a region of the landscape other than where they were meant to stay. What's more, their toxic bodies, as you have referenced, became devastating for the native populations of species that were ill-adapted to consuming the toads.

          The good news is that we are actually witnessing involuntary natural evolution in conjunction with human-induced adaptation. Not only are researchers catalyzing the adaptation of threatened species to avoid eating the cane toad, other species are learning on their own how to handle the toxin. Some bird species, including the black kite, learned to consume only the belly of adult toads, which do not contain the toxin. Certain species of aquatic frogs can consume the tadpoles of the cane toad before they develop the toxin glands.

          I agree with you that we should use our power to help "nudge" species in a direction that stabilizes their populations, but it is conditional. We should not interfere before we have a proper understanding of the ramifications of our experimentation. The cane toad implementation is an example of how interference can go wrong and how it can be righted.

Showing single comment thread. View the full conversation.