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Extinction rates, hands off the islands

  1. Oct 26, 2011 #1
    This is more environment than biology, so I thought this was the best place to post this.

    Craig Loehle and Willis Elsenbach compare extinction rates of continents and islands. They find that

    Trivially, isolated species on islands are often highly specialized and not equipped to deal with major changes like the introduction of alien pests and predators.

    Therefore, programs aimed at preservation of island endemic species, are likely much more effective than all the efforts to prevent the Panda from dying out. Or?
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  3. Oct 26, 2011 #2


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    Trivially? Yes. But realistically, this is a huge ethical and political can of worms.

    If clearing a forest endangers an owl, then it is a simple/direct matter to save it by choosing not to do that (if one so desires). But islands are subject to the collective, secondary influence of humans, so that requires collective decision-making.
  4. Oct 26, 2011 #3


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    Whether the whole habitat of the species is threatened , or just a local area, is a factor in the species survival.

    In an island environment the whole population of the species is threatened. The species can not relocate, nor is there a backup population of sufficiant viability if the threat is removed.

    Consider a continental species. These are usually spread over a wide area and a threat to a localized area the size of 1000sq mlies of the species habitat ( an island ) may be only 10% or less of the whole population.

    The wolf was eliminated from its local habitat in Colorado ( is that the correct area ). Several years ago a few mating pairs from its population from Alberta were re-introduced and the wolf has proliferated once again in that local area.

    In the case of the paraire buffalo an alien pest ( humans ) was introduced into its habitat in the 1800s. The whole population of specialized buffalo ( grass plains mammal ) with no defence against this new predator was stressed to the point of extinction. Very few buffalo remain. The present population has no chance of recovery mainly because its habitat has been altered to such an extent that only with human intervention are they able to survive.
  5. Jan 12, 2012 #4
    Why all the concern about species extinction? It is a natural and necessary part of evolution through natural selection. Whether the proximate cause of extinction is predation, a disease vector, rise in sea level, continental glaciation or whatever, its all natural and all part of natural selection.

    Human beings and their activities are all a part of the natural world. We are not "unnatural", and it is unscientific to separate us from other natural phenomena.
  6. Jan 12, 2012 #5


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    There is an incredibly good reason to be worried. We depend on the ecosystem not only for our lives but also for the success of our civilisation. If we blithely ignore causing extinctions we risk creating an ecosystem collapse that may threaten us through famine or economic loss. In a small area this might not be that noticeable but if it it happens in many areas at once you are looking at an incredibly expensive and potentially dangerous situation.
  7. Jan 12, 2012 #6
    In which case, we must either adapt to the changed circumstances or risk becoming extinct ourselves--to be replaced by some more adaptable species. Rats, perhaps, or cockroaches.

    Quite frankly, I cannot envisage any likely ecosystem change resulting in the collapse of all civilization. This is doom-mongering of the worst sort.

    Man is an extremely adaptable animal. This is his defining characteristic. If some ecological disaster should result in a drastically reduced human population, then this might be considered a good thing.

    The knowledgeable, the prepared, and the lucky will survive to reproduce. The ignorant, the unwary, and the unlucky will perish. The process is called natural selection.
  8. Jan 12, 2012 #7


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    Collapse of civilisation is obviously worse case scenario and unlikely though it is arrogant in the extreme to think that it couldn't happen. Rather there is a big risk of economic and thus social upheaval from relatively simple collapses such as the loss of soil biodiversity, pollinators etc. Also the fact that natural selection exists doesn't really tell you anything about how to live your life or decide societal matters; one certainly shouldn't say "that's life! The strong will survive at least." This is the type of thinking that could lead to totally avoidable problems of the nature I have mentioned.
  9. Jan 12, 2012 #8
    Type of thinking? Isn't sciencific thinking/the scientific method good enough? I would think that any human biased political thinking either way -groupthink versus individual gain- can only lead to a blurred, inferior vision on reality?
  10. Jan 12, 2012 #9


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    I'm not sure I understand, I was referring to the "it's only evolution; let it happen!" attitude which is guilty of naturalistic fallacy and misunderstanding of the issue.
  11. Jan 12, 2012 #10
    Anyone who visits the UK these days should have the Eden Project high on their list.

    Here they create a variety of habitats/environments similar to those encountered in most parts of the world.
    Some of their work provides habitats for saving threatened (mostly plant) species especially island species.
  12. Jan 12, 2012 #11
    Well, I observe a discussion based on some preset and opposite assumptions. Sorry -if I exagarate- but between 'blithely ignore' induced armageddon versus nature-does-what-nature does. I think somewhere in between, there must be a clean objective scientific process that would find out ideally what mankind should do to optimize both the conditions for nature and civilisation.

    Saving the panda for instance? A big highly optical program for an extreme specialist that is inevitably going the way of all other extreme specialists, when their biotope changes slightly. Could we have done better things with the same effort?

    Which obviously was in the gist of the OP. Be sure to do the right thing.
  13. Jan 12, 2012 #12


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    Ah I see. Regarding saving the pandas there are a few pros that might not seem obvious. The biggest is that it raises awareness and funds for conservation programs, unfortunate as it is the public probably wouldn't donate to the WWF if it's image looked like this. Overall though I don't know whether or not the case could be made for the panda.
  14. Jan 12, 2012 #13


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    The OP's quote was apparently only talking about animal species.

    So far as human survival is concerned, it might be more relevant to consider that 80% of global human food supply comes from just four crop plants: wheat, maize, rice, and potatoes. (Source: recent BBC radio broadcast). And according to http://en.wikipedia.org/wiki/Staple_food 90% of world food energy intake comes from just 15 crop plants.

    A proper risk analysis looks at both the probability of an event and its consequences. Whether the (rather high) probability of pandas going extinct has as much consequence as a new global disease attacking a staple food crop is debatable. But hey, everybody knows GM food is bad, so save the pandas!!!!!
    Last edited: Jan 12, 2012
  15. Jan 12, 2012 #14
    good point, and a sad point too. Obviously with our strong subjective biases we need manipulations like that. We are no "borg" nor "mr -logic- Spock" so we can only achieve goals by manipulation. I ponder a lot if our primitive subjective instincts, required to survive in a competing natural world, are turning against us now we have achieved "civilisation".
  16. Jan 12, 2012 #15


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    These are very good points however even restricting the topic to animals it is inevitable that plants and crops will come into it. Ecological interactions are innately intimate; if a pollinating animal species (or a critical organism lower or higher up the food chain) goes extinct or massively dies off the crops will suffer.
    Lol yup. Thinking about the last comment it occurs to me that it would be a pretty big embarrassment to the WWF if their logo creature was wiped out...
  17. Jan 12, 2012 #16
    Come on, Ryan, you're a scientist. Drop all that "might, may, could, possibly" crap and present the scientific evidence to support your hypothesis--if you can find any.

    There have been plenty of species extinctions in man's history. Name even one that has resulted in "economic and social upheaval". Oh sure, there have been strictly local tragedies and inconveniences, but anything on a global or even a continental scale? How many losses of human life can reliably be traced to species extinction? I doubt if there's any.

    No. What's happened is that your esthetic sensibilities have been offended by the mere idea of species extinction and you've blown this up to some sort of threat to mankind.

    Again, show me the evidence to support your hypothesis. And remember, computer models are not considered scientific evidence. I want evidence from the verifiable past or the here and now.
  18. Jan 13, 2012 #17


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    You want evidence that mankind is dependent on various ecosystem for survival and profit? You realise that all I've said is that ecosystem collapse can be dangerous for humans physically and economically (i.e if the crop you eat or sell dies) and I've said that worst case if that happened in many different ecosystems it could drastically destabilise our global civilisation via mass famine, cash crop loss etd? I am not actually arguing that civilisation will collapse at all I'm merely acknowledging the possibility.

    Yes extinctions have happened on a global scale; they're called mass extinctions and they lead to a dramatic loss in carrying capacity. At the moment we are entering the Holocene extinction event which is largely hypothesised to be caused by mankind.

    I'm not going to be around much this weekend and rather than doing a literature search for you I'm just going to leave you with some key search terms that bring up a large number of results:
    Loss of pollinators
    Effect of biodiversity loss
    Economic effect of biodiversity
    Species extinction harms humans
    Ecosystem collapse effect on humans
  19. Jan 13, 2012 #18
  20. Jan 15, 2012 #19
  21. Jan 21, 2012 #20
    They confine themselves to since 1500. The extinction of large animals on Eurasia, the Americas and Australia in since homo sapiens moved in meant that most of the most vulnerable species, those in need of large ranges, were gone by the time they start looking.

    Even then their figure for 3 mamals is pretty suspect.

    Whats more mammals tend to attract massive conservation efforts and those only kept going in captivity are kept of off the lists of extinction.

    Its pretty well known islands have far higher extinction rates due to in part confined ranges and millions of years of lack of large preditors on many of them. The arrival of cats, dogs, rodents and humans set of little pockets of mass extinction.

    Not sure what the point of this paper is, actually I just checked who published this

    Uh huh. So its a the pulping industry saying 'dont worry about continental forests'.
  22. Feb 17, 2012 #21
    Having read some of the article, I just wanted to point out that they consider Australia to be an island in their study because of its isolation. Thus, the marsupials you've listed (save for one) would factor into the numbers used for island extinctions.

    Whether this serves a 'political' agenda is an entirely different matter.
  23. Feb 25, 2012 #22
    Why is it that the same scholars who champion evolution through natural selection when arguing with Creationists do an abrupt about-face when faced with its practical application--species extinction.

    Natural selection cannot exist without species extinction. Species extinction is the modus operandi of natural selection. It is Nature's way. Accept it. Learn to live with it.
  24. Feb 25, 2012 #23


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    The problem, klimatos, amongst other things is human caused habitat destruction is mass extinction that can greatly reduce biodiversity. This has consequences on human society both physically and economically. In addition it isnt aesthetically pleasing to live in an area of low biodiversity.

    On top of that it is a naturalistic fallacy to say that because extinction occurs then it is good for it to happen.
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