Extinctions inevitable

How many times have you read or heard comments from deniers that animals, plants and fungi will adapt to new environments or evolution will provide new capabilities as the climate changes? I know a number of denier dens like to highlight scientific papers where researchers have studied the effect of climate change on a particular organism where the result has been neutral or positive, and use this as “evidence” that everything will be ok.  CO2 Science has even compiled a list of papers on aquatic organisms.

I am more than happy to concede that some individual species will cope with climate change and some will actually benefit,  but what these studies don’t do, is look at ecosystem responses and the potential for ecosystem collapse. In studies of response to environmental disturbance, generally, ecosystems respond well to and actually require low to middle levels of disturbance. Disturbance keeps ecosystems healthy by facilitating a whole range of processes from nutrient cycling to niche partitioning. The end result is usually high levels of biodiversity. Think of rainforests with the occasional tree falling over. When disturbance is high (acute or sustained) generalist species, those with a wide range of tolerances, outcompete specialist species and the end result is low biodiversity and/or altered ecosystems. Think of a rainforest after a cyclone (acute) or desertification of rangelands (sustained).

Anthropogenic climate change is starting to create both acute and sustained disturbances in natural ecosystems resulting in latitudinal and altitudinal range shifts in tens of thousands of species as well as phenological adjustments. This in turn leads to changes in the biodiversity and function of ecosystems as they adjust to changes in niche fulfilment and abandonment with generalists coping better than specialists. So, what will be the fate of individual specialist species?  Will they be able to adapt or evolve quickly enough to adjust to the rapid rate of climate change we are experiencing? Being specialists, we can rule out adaptation. That leaves evolution.

What I have found amongst many non-scientists who have limited knowledge of biology, is a failure to appreciate timescales. As humans, we tend to measure time against our own lifespans. The concept of evolutionary timescales is lost. It is very difficult to observe evolution by natural selection in species as it can take hundreds to thousands of generations to bring about tiny changes that may result in some favourable outcome but of course evolution is blind and subject to chance. There is no guarantee that species will have the genetic mutations within a population that will allow survival in a changing environment anyway. When environmental change happens slowly, the chance that beneficial genes will evolve is greatly improved.

So, will species evolve quickly enough?

Research undertaken by Ignacio Quintero and John Wein, from the University of Arizona, reveals that in order to avoid extinction due to anthropogenic climate change, a large number of vertebrate species will have to evolve 10,000 times faster than they have in the past.

“We found that on average, species usually adapt to different climatic conditions at a rate of only by about 1 degree Celsius per million years, but if global temperatures are going to rise by about 4 degrees over the next hundred years as predicted by the Intergovernmental Panel of Climate Change, that is where you get a huge difference in rates. What that suggests overall is that simply evolving to match these conditions may not be an option for many species.” Dr John Wein

For a more detailed report on this study, go here.

For an excellent paper on predicting the impacts of climate change, go here.

Here is the paper Quintero and Weins paper…

Quintero & Wiens (2013) Rates of projected climate change dramatically exceed past rates of climatic niche evolution among vertebrate species. Ecology Letters DOI: 10.1111/ele.12144

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Filed under Climate Change

9 responses to “Extinctions inevitable

  1. On land, smaller, more mobile, flying and/or burrowing creatures. Looks like insects, small birds and rodents mostly. In the oceans… it’s just bad. 500+ ppm is a terrible event.

  2. I am a bit hopeful because of Orgel’s rule: Evolution is cleverer than you are. The species we have are there also because they were good at adapting and evolving in the past. As everyone they are the standing on the shoulders of a huge number of survivors.
    On the other hand, we are already seeing an increase the species extinction rate and to count on nature solving the problem effortlessly is irresponsible, is playing with the biggest treasure entrusted on us. (And also something you would not expect from a real conservative.)

    • Hi Victor and welcome.

      I’m not hopeful at all. Evolution has the appearance of being clever but it really comes down to the weight of numbers and chance and time. Time and numbers are a real problem for a large number of specialist species. As the study I highlighted mentions, some of these species will need to evolve at 10000 times the natural rate. There are also five or so myths about evolution, one of which is that it is directional. If thesespeciesdon’t possessbeneficial mutations in great enough numbers they will peg out.

      Conservative as it applies to politicians and their supporters is the greatest misnomer going around.

      • Thank you.

        Making predictions about the climate system as a complex system is already on the edge of what science can do. I am quite sure things will happen in the climate system, which we did not see coming. (And no climate “skeptics”, uncertainty does not mean that nothing will happen; it actually makes the argument for mitigation stronger, because uncertainty makes it harder to determine what we should adapt to.) The fast disappearance of the Arctic ice sheet may be an example.

        Making prediction about evolution as an adaptive complex system is probably beyond our reach. What is the natural rate of evolution? The average long term rate? Evolution often happens in fast jumps (still extreme slow from a human perspective) and when under stress. Humans have evolved much faster as average since we started with agriculture and started eating and living in a very different way as hunters-gatherers. It is likely no coincidence that chronic stress is may damage your genome. That is an elegant way to evolve faster when conditions apparently require so, naturally in an undirected way. And the species have the option of adapting. Maybe a second behavioural repertoire is already coded into their genes, just not that often active under current climate.

        That being said, I do expect that the extinction rate will increase. If only because not every species will be lucky to find a solution in time and because of all the other stressors we already place on nature. Extinction is one of the largest catastrophes possible. We are destroying billions years of evolution and design that way. And it will never return, it is gone for ever. I just expect the uncertainty range to be huge.

        Orgel was not thinking of you and me, when he said “evolution is cleverer as you are”, but of biologists and experts on evolution. The ones who wrote the study you linked.

  3. If we continue business as usual, earth will continue to exist with different species. Humans will not be on that list.

  4. Reblogged this on Standard Climate and commented:
    Well, when you speak about wind power, apparently deniers cannot hide their worries and deep concerns about The Birds! The question is; why should the species be under such pressure? There are cold and warm zones in this planet. Shifting the cold zones to warm zones meaning is “extinctions inevitable”.

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  6. “As humans, we tend to measure time against our own lifespans.” I think this is one of the main challenges. We measure, in the long-term, from our grandparents to our children or maybe grandchildren – a blink of the evolutionary eye.
    There’s an interesting project (which you’ve probably already heard of) that aims to foster long term thinking, the Long Now Foundation – also home to the Revive and Restore project to bring back extinct species. Thanks for an interesting post!


    • Hi PK and welcome. Thanks for your comment.

      I had heard something about the long now project and I think it’s certainly an interesting project. I tend to be a little pessimistic about changing people’s perspective of time and getting them to think long term. I think that as we have become “smarter” many have lost the plot and think we are somehow exempt from nature. In the western world, the vast majority of us don’t have to worry about where our next meal is coming from, how we are going to find clothing or shelter and we seem to forget that the overall drive in nature is to preserve our genetic material in future generations. We have allowed our basic survival instincts to manifest as greed and we have become short-sighted as a result. How we overcome that is beyond me. I suspect that when climate catastrophes are on the doorstep of the short-sighted, even then, instead of changing their position of myopic intraspection to a more worldly outlook with a view to the future many will merely give up and claim, “it’s too late so why bother.” This will of course just be an excuse to continue with business as usual and disappear with their heads, still well and truly lodged up their own arses.

      On bringing back extinct species, I have to question what the point is if we are bringing them back into a world without enough of their natural habitat or the climatic conditions for them to be self-sustaining? How much money is wasted breeding pandas and tigers that will never have their own ranges due to our continued destruction of their habitats? Couldn’t the money be better spent getting us off fossil fuels and reducing our pressure on the natural world?