jump to navigation

Loss of Apex Predators Can Devastate Ecosystems: Implications for the Hedonistic Imperative July 30, 2011

Posted by Metabiological in Ecology, Transhumanism.
Tags: , , , ,
add a comment

One of the big debates in the field of ecology is whether or not ecosystems are regulated by bottom-up or top-down processes.  Bottom-up refers to elements at the bottom of the food chain that control the structure of the biotic community; such as the amount of nutrients in the environment determining the composition of the primary producers which in turn determine the composition of the herbivores and predators.  Top-down control is just the opposite, in which the organisms at the top of the food chain (i.e. the apex predators) control the structure of the rest of the ecosystem through the pressure they exert through predation.

The debate has been raging for decades now and it is now widely acknowledged that both types of regulation occur in nature.  As such debate has largely shifted to the question of which form predominates and under what circumstances either form will.  Personally, and I emphasize this is a personal opinion, I tend to think that bottom up processes largely control the structure of ecosystems (annual rise and fall of nutrient levels in marine systems, sunlight in almost all systems) with top down processes only becoming apparent in areas where bottom up limitations are largely negligible (areas where nutrients are abundant all year round).

Still decades of research have shown that in many systems the presence of an apex predator can have a drastic effect on the ecosystem in question.  In a recent study led by James Estes, who knows a thing or two about apex predators, a worldwide assessment of human induced trophic cascades attempts to bring the problem into focus.

According to first author James Estes, a professor of ecology and evolutionary biology at the University of California, Santa Cruz, large animals were once ubiquitous across the globe, and they shaped the structure and dynamics of ecosystems. Their decline, largely caused by humans through hunting and habitat fragmentation, has had far-reaching and often surprising consequences, including changes in vegetation, wildfire frequency, infectious diseases, invasive species, water quality, and nutrient cycles.

The decline of apex consumers has been most pronounced among the big predators, such as wolves and lions on land, whales and sharks in the oceans, and large fish in freshwater ecosystems. But there have also been dramatic declines in populations of many large herbivores, such as elephants and bison. The loss of apex consumers from an ecosystem triggers an ecological phenomenon known as a “trophic cascade,” a chain of effects moving down through lower levels of the food chain.

Though this is interesting in it’s own right what really got me thinking is what implications this has for the Hedonistic Imperative.  I’m going to assume that anyone reading this has at least a basic working knowledge of what the Hedonistic Imperative is (if not, see the link to the right) and if you do then you probably already know where I’m going with this.  Apex predators will not, and cannot, exist in a world free from suffering.

What would this mean then?  Would a world without predators be a barren and lifeless one, or completely chaotic with ecosystems rising and falling like the tides?  Well, not necessarily.  A lot of the talk surrounding the discussion of apex predators gets bogged down in emotionally charged language that does little more than distort the issue.  It doesn’t help that apex species are almost exclusively “charismatic megafauna” (as one of my professors delights in calling them) and tend to attract attention and importance in the human psyche sometimes out of proportion with their actual role in the ecosystem.   But to get back to the emotionally charged language part all you need to do is look at some of the words used when describing the consequences of removing apex species.  Devastate.  Destroy.  Collapse.

Those are some pretty heavy words, but are they accurate?  Yes and no.  There’s no doubt that the loss of an apex species can drastically change the structure of an ecosystem and for many species the changes are negative.  However, that is not always the case.  Take arguably the most common example of a trophic cascade; the loss of sea otters in the eastern Pacific and the growth of “urchin barrens.”  In short, sea otters were hunted near to extinction and the loss of this species lead to a massive growth in sea urchin populations, of which the sea otter was a primary predator.  This explosive growth lead to a reduction in the size of kelp forests as urchins devoured everything in their path.  The result was areas stripped clean of kelp and colloquially known as urchin barrens.

This is a fairly well known story and one with a fair amount of evidence behind it, though the truth is a bit more complicated.  Whether or not an explosion of the urchin population results in a true, sustained barren seems to depend on a variety of local factors including temperature, seasonal changes in food quality and the presence of other predators.  In short, simply removing the top predators does not necessarily result in ecosystem collapse.

That right there is the point I’ve spent the last seven paragraphs or so laboriously trying to get to.  There are other ways to regulate ecosystems besides requiring predators to occasionally thin out the herbivore populations.  This, as stated above, has important implications for the Hedonistic Imperative as it provides us with the possibility of designing self-sustaining ecosystems without the need to release what are essentially serial killers into them.

The use of the word self-sustaining there is important.  An important critique of HI is that redesigning the world’s ecosystems will require a massive, centralized decision making and control body and constant monitoring and intervention to stay one step ahead of evolution.  Unfortunately this is likely to be true to a large degree.  As such it is important to look for any opportunity to take the burden off of ourselves so to speak and arrange for cruelty-free ecosystems to sustain themselves through natural processes.

How can we do that?  Well here it gets a little murky since any real solution is probably centuries away from us at our current level of development.  Still, even with our woefully inadequate understanding of how ecosystems function we can at least put forth a couple of ideas.

One way to control population sizes without the need for predators is to control population birth rates.  Obviously we won’t be able to go around and hand out condoms to the animals so organisms will have to be engineered in such a way as to ensure low growth rates and stable populations sizes.  An evolutionary solution (i.e. engineer individuals to produce low amount of sex cells or breed only occasionally) will likely be unsustainable in the long-term since mutants which overcome those limitations will likely be able to out compete their slow growing neighbors.  A better solution might be designing animals to be dependent on something within their environment that keeps their birth rates low.  Fruiting plants might be designed so that their fruit contains chemical compounds which inhibit sperm or egg production.  This isn’t as far-fetched as it sounds and has tentatively been demonstrated in certain interactions between sea urchins and algae.  Even this would be vulnerable to evolutionary mutations so vigilance would still be required.

A similar method could be used with virus’ or bacteria that target an organisms reproductive system in the way described above.  Diseases actually would make a very effective means of population control due to the density-dependent nature of their effectiveness.  If the population drops below a certain threshold  the disease ceases to be as effective, due to the increased difficulty of finding a host, and the population is given a window to recover.  This advantage applies to all density-dependent checks on population growth (competition for mates and resources, predation, space limitation) but most of the rest would be very difficult to alter to ensure no suffering.  Diseases would also have the advantage of evolving with their victims to stay one step ahead them.  Of course by extension diseases present the obvious problem of mutating to attack organisms in some other way, one which may involve suffering and death.

Of course their are more fanciful, or perhaps I should say sci-fi, options as well.  Perhaps we could engineer a primitive, for lack of a better word, neural network a la Avatar that allows some sort of rudimentary communication between organisms, allowing the balance between food supply and population to be maintained.   That may be a little too speculative even for this article so I’ll leave it their for now.  The point is that a loss of predators from an ecosystem need not mean disaster and need not be an obstacle to the Hedonistic Imperative.  We can find ways around it using processes already present in the natural world.

Advertisements

Animal Suffering vs. Animal Slavery January 3, 2011

Posted by Metabiological in Ethics, Transhumanism.
Tags: , , , ,
comments closed

Are non-humans deserving of rights?  Does husbandry amount to enslavement?  Is animal testing acceptable if it sames human lives?  These questions and others lie at the heart of the debate between animal rights and animal welfare.  More than simply a theoretical discussion it has important implications for not only what place non-humans currently have in our society but how those roles may change in the coming decades.  Though science fiction stories are replete with examples of uplifted species or hybrid splices society at large has yet to consider what our response to such things should be.  One reason for this is that we still haven’t figured out where non-humans fit into our current paradigm.

Though both groups campaign against cruelty to animals there are deep, fundamental differences between them.  The crux of the argument can be summed up by the question of whether or not non-humans can or should possess the same rights we give to our fellow humans.  What rights these are can vary depending on who is being asked the question but the generally include the more familiar ones: the right to live, the right to liberty (or to not be enslaved) and so on.  The short version is that animal rights advocates support this while animal welfare advocates do not.  The slightly longer version is more complicated.

What this debate hinges on (as it appears to me) is the question of personhood.  A person here is defined as a sentient being capable of self-awareness, the ability to contemplate it’s own future and the ability to feel pain.  That last one is arguably the most important as without pain, suffering or something like it becomes very difficult to differentiate between positive and negative experiences.  The animal rights camp, following the works of people like Peter Singer (who oddly enough actually disagrees with a fair amount of their rhetoric) generally believes in extending our circle of personhood to include either some or all of the rest of the animal kingdom.  Note that animal rights groups usually stop at animals and don’t generally push for the rights of plants or ecosystems a la the Deep Ecology movement.  Animal welfarists reject this extension of rights to non-humans out of hand and continue to regard non-humans as non-sentient.

This disagreement leads to drastic differences between two groups that otherwise would seem obvious allies.  Welfarists have no problems with the act of eating meat itself while many rightists advocate veganism.  Rightests condemn, and in some cases sabotage, animal testing while welfarists generally support its use.  Once again, the issue in all of this is one of personhood.  If non-humans are persons than they deserve the rights that we as a society already extend to humans (to do otherwise is speciesism.)  Some of those rights will naturally be the right not to be eaten, not to be experimented on, and not to be imprisoned.  If they are not persons then they are not deserving of any of those.  Thus as God commands in the Old Testament, man shall have dominion over the rest of the natural world.

So who has the stronger argument?  It depends on who you ask but from where I’m standing I’m not sure either one gets it.  The major problem with the welfare approach is that it ignores the fundamental right that all sentient life shares: the freedom not to suffer.  Welfarists may pay lip service to this by advocating the abolition of unnecessary suffering but the question as to what exactly that is is a constantly moving target.  To a welfarist an animal is a tool.  Perhaps a cute tool, one which may provide great service to it’s human masters and which should be kept in the best condition possible, but a tool none-the-less.  The purpose of an animals entire existence lies in what in can provide to mankind; whether that be companionship, testing the next generation of cancer drugs or simply serving to sate a primal urge for dead flesh.

By contrast, animal rightists respect the rights of animals to a fault.  They fully believe that animals should be free from suffering at human hands and attack notions that non-humans exist to serve humankind.  Unfortunately they too lose track of their overriding goal, though they go about it in a manner quite different from the welfarists.  All to often rightists fall into the “Gaia trap,” viewing the natural world in an over-idealized and nostalgic light.  Their position can best be summed up as one of non-interference with the natural world, a sort of “life will find a way” naivety wherein animals are freed from the “tyranny” of human slavery.  There opposition to animal enslavement even extends to companion relationships which, while certainly not without there difficulties, are among the best relationships humans have cultivated.  More importantly this view completely  ignores the horrifying reality of both Darwinian evolution and daily life in the natural world, “red in tooth and claw”, wherein the vast majority of life of those born will eke out a brief, harsh existence of fear and anxiety before meeting their end at the hands, or teeth, of another.

The question of how we treat non-humans is one of the most important debates facing both philosophy and society as a whole.  To those who value the abolition of suffering it is imperative that we choose the right approach.  Neither the welfarist nor the rightist approach will do and as such a third is needed.  Call it animal guardianship.  Call it the quest for Eden.  Or perhaps, just call it the Hedonistic Imperative.

The Problem with Parasites December 12, 2010

Posted by Metabiological in Ecology, Ethics.
Tags: , , , , ,
add a comment

David Pearce is fond of saying that the last instance of suffering in the world will be a datable event. As a supporter of the Hedonistic Imperative I believe it is humanities destiny to accomplish this. However as a student of ecology I am also more than aware of the monumental proportions of the task that lay before us. To not only eliminate suffering but to do it in a way that results in a functioning, self-sustaining ecosystem (there are reasons to do it this way that I will come back to another day) is a task that will take resources, planning and time almost beyond comprehension. I offer one small segment of the problem here: the problem with parasites.

Parasites, even more than predators, are the ultimate challenge to HI. From a strictly logistical standpoint they present far greater difficulties. Firstly, they are generally much smaller. This may sound obvious but the macro scale of most of the worlds predators makes them easier to deal with. Large animals can be tracked, observed and altered with far less difficulty than tiny ones, let alone microscopic ones. Secondly, there are far more parasites in the world than predators. This is related to the first point in that you can fit far more smaller animals into an ecosystem than you can larger ones. Thirdly, parasites are not always obvious. A predator stalking, killing and devouring an organisms leaves tell-tale clues behind (the most obvious of which is a corpse) that are easy to comprehend. Even when direct evidence of predation cannot be found it can be inferred through indirect methods such as large scale changes in the population density or distribution of the prey. Parasitism does not always present such a clear case. Though many parasites can certainly be detected through their negative effects it is not always as clear what is causing the problem. Often times the only sign that a parasite is present is during a autopsy.

It is not simply logistics that make parasites our greatest obstacle. The suffering caused by parasites is far greater than that caused by predators. Though terrifying, predation at least ends the suffering of the prey, albeit through death. Parasites by comparison can be present for years, in some cases throughout the whole natural lifetime of the organism. This is without discussing the subject of parasitoids, creatures that lay there eggs within the bodies of their hosts. Anyone who has watched a tarantula being eaten alive from the inside out by a wasps larvae cannot help but shudder.

So how to we fix this problem? One solution is to simply wipe parasites out. Others have considered the controlled extinction of certain species as a means to reduce suffering and though at first glance it may seem crazy it is not as outlandish an idea as it may seem. Many mosquito populations have already been eradicated through the use of pesticides such as DDT to prevent the spread of malaria. Unfortunately, these actions have met with varying and limited degrees of success with the biggest problem being the evolution of individuals resistant to the effects of the pesticides. For this reason and the shear logistical nightmare of attempting to wipe out every parasitic species on earth we must relegate extinction to nothing more than a situational tool.

A better solution is to use the tools that evolution has already provided for us, namely to shift the relationship parasites have with there hosts. Mutualisms are positive interactions between two or more species that result in a benefit for all individuals involved. Arguably the most common example is between various insect and flower species; the insects receive nourishment from the nectar while the flowers use the insects for pollination. This scenario is well known to even non-experts but mutualisms are far more wide spread than most people realize. Pilot fish eating parasites from sharks, bacteria fixing nitrogen for plants in exchange for food, snails eating the fouling organisms from the algae they live on; each of those and many more is a beneficial interaction that took no human intervention to create.

It may seem at first that transforming a parasitic relationship to a mutualistic relationship would be rather difficult but in this case looks are deceiving. The important thing to keep in mind is that mutualisms are not examples of true cooperation between species. Indeed they are more properly identified as systems of mutual exploitation with the positive benefits merely being a side effect of each species taking what it needs. While the evolution how these relationships developed is not well understood it seems likely that many mutualisms originally evolved out of parasitic relationships.

Critics of HI have noted that any attempt to re-engineer the natural world in the name of eliminating suffering will require massive top-down regulation and control, with all the problems associated with such systems. While one can argue the degree to which this is true it seems likely that to some degree it must be. Our goal then should be to look for any opportunity to let evolution do our work for us, allowing us to merely dip our hand into the stream whenever we need to correct our course.

Hedonistic Imperative Slowly Moves into the Mainstream December 5, 2010

Posted by Metabiological in Ethics, Transhumanism.
Tags: , , , ,
add a comment

David Pearce’s Hedonistic Imperative has arguably been one of the most influential ideas within transhumanism.  Even those who don’t support it, and there are many that don’t, can’t help but respect both the scale of the vision and the intellectual vigor behind it.  For myself reading it the first time was an eyeopener.  As a young atheist I had been unimpressed by the ethical stance of the various humanist organizations which seemed to go about the business of ethics without any definition of what constitutes “good” or “evil”.  HI not only provided an ethical framework (negative utilitarianism) that was well-grounded in philosophy but a vision of a better world that rivaled and even surpassed the dreams of paradise espoused by the world’s religions.

As such I am always happy to see these views break into the mainstream.  Jeff McMahan’s article in the New York Times “The Meat Eaters” was groundbreaking in this regard and now we have Oscar Horta’s publication.  Horta’s work, which deals with the problems associated with species reintroduction, strikes particularly close to home for me as an ecologist in training.  It is a complex problem and one that according to Horta we are not going about in the right way.

His article asks the question of whether or not it is moral to reintroduce carnivores, in this case wolves, into their former range.  The ecological argument is that top predators help to stabilize the ecosystem and prevent major changes in community structure that can occur through over-grazing.  This is not a controversial statement in ecology with the spread of sea otters into former ranges along the California coast arguably being the best example of it.  Horta attacks not only the ecological argument of reintroduction but also questions the moral hypocrisy implicit in such a policy.

I won’t go in depth into his arguments since you can and should read it for yourself but I will tell you that some of his arguments are very impressive, particularly those against the deep ecology crowd.  The take home from this is that while he calls into question our current interventions he does not call for them to stop but only to be modified.  Nature is not good simply because it is nature and intervention is not bad for simply being an intervention.  When used properly, such as in the reduction of suffering in the natural world, it can be one of our most powerful tools.