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

NASA To Send Astronauts To Asteroid Within 15 Years July 23, 2011

Posted by Metabiological in Beyond Earth.
Tags: , ,
add a comment

First of all, credit to Luke Parish for totally calling this in the comments of my last post.

With the space shuttle now history, NASA’s next great mission is so audacious, the agency’s best minds are wrestling with how to pull it off: Send astronauts to an asteroid in less than 15 years.

It has the dreamers of NASA both excited and anxious.

“This is a risky mission. It’s a challenging mission,” said NASA chief technology officer Bobby Braun. “It’s the kind of mission that engineers will eat up.”

This is a matter of sending “humans farther than ever before,” said NASA Deputy Administrator Lori Garver. It is all a stepping stone to the dream of flying astronauts to Mars in the mid 2030s.

“I think it is THE mission NASA should embrace,” said University of Tennessee aerospace professor John Muratore. “To be successful at this mission, you’ve got to embrace all of the technologies that you need for Mars.”

I’ll be honest I didn’t expect this, mainly because the impression I’ve been getting out of NASA is one of a ship lost and adrift at sea.  Their big problem for the past decade or so has been not so much a lack of skill or ingenuity but a lack of focus.  If they do put all their weight behind this mission, and according to the article this is a presidential order for what that’s worth, than this could be exactly what the space agency needs.

Firstly, landing on an asteroid is hard.  No, really hard.  In fact the word land isn’t even appropriate since the gravity is so low you’d just bounce off if you tried to.  This is the kind of challenge that sends aerospace engineers into bouts of hysteria and drives them to think of solutions they otherwise never would have imagined.  Secondly, even though it’s hard it’s not nearly as hard as the other big idea NASA has been kicking around; sending humans to Mars.  In fact in a lot of ways (timeframe, technology required, logistics) landing on an asteroid is somewhat of a practice run for getting to the red planet.  Thirdly, it’s a much better idea than establishing a base on the moon.

Personally I think the idea of a moon base is awesome but it’s not the job NASA should be doing right now.  The costs of not just setting up but of maintaining a base are way beyond NASA’s capabilities right now which makes a short term mission more appealing.  In addition there’s the simple fact that we’ve already been to the moon.  True we never set up a base their but going back will strike a lot of people as been there, done that.  An asteroid on the other hand has novelty, it has the element of exploring the unknown that can drive the public’s imagination.  Also, and perhaps most importantly, figuring out how to land on an asteroid has important implications for keeping our species alive.  Asteroids strike our planet all the time and as of right now even if we knew a big one was coming the is next to nothing we could do about it.  Landing on an asteroid would be the first step in learning how to alter it’s course.

I’ve been very down on NASA in recent months but this news cheers me up.  I’ll want to wait and see if this actually bears fruit but so far I’m excited.

The Shuttle Era Is Over July 21, 2011

Posted by Metabiological in Beyond Earth.
Tags: , ,
add a comment

Mission complete Houston.”  What more needs to be said.

 

NASA Arrives at Really Old, Really Big Asteroid July 18, 2011

Posted by Metabiological in Beyond Earth.
Tags: , , ,
2 comments

Get used to it.  Because once the space shuttles retire stuff like this is all your going to be hearing out of NASA for awhile.

 NASA’s Dawn spacecraft was captured into orbit around the massive asteroid Vesta after a 1.7 billion-mile journey and is preparing to begin a study of a surface that may date to the earliest era of the solar system, the space agency said Monday…

Vesta, 330 miles in diameter, is the second-most massive object in the asteroid belt and is believed to be the source of many meteorites that fall to Earth.

Dawn will continue to approach Vesta over the next three weeks, search for possible moons and make more navigation images. It begins gathering science data in August. Vesta’s gravitational pull on Dawn will be measured to more accurately determine the asteroid’s mass.

But I’m not bitter (no really, I’m not).  Projects like this will deliver more data for less cost and almost zero chance of the loss of human life.  It will help the space agency continue its duties in an age where NASA frankly doesn’t getting the funding (either in amount or stability) that it deserves.

But it’s not very exciting is it?  Hearing that NASA entered into orbit around a hunk of rock in the asteroid field is not, apart from a very small group, going to excite people.  Touting the benefits and positives of this kind of mission, real though they may be, is largely a waste of time if you can’t capture the imagination of the public.  Yes I realize that the private space sector will start to take over the actual act of getting people into space.  I’m still not sure how I feel about that but whether you’re for it or not you must realize that we still need NASA.

NASA once ignited an entire nation.  It pushed several generations to explore science and engineering.  It made people dream big.  We need NASA to do that for us again and this isn’t going to cut it.  Like it or not, “we’ve arrived at orbit around the asteroid” is never going to top “One small step for man…”

New Solar Storage Technology Makes Debut July 12, 2011

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

While solar power has shown a lot of potential as a source of renewable energy the one major problem it has struggled to overcome is its intermittent nature.  Not only does this have the rather obvious problem of not providing electricity at night but it also hamstrings it in its ability to respond to changes in energy demand.  Now a company in Spain has demonstrated technology that may allow the solar industry to overcome that limitation.

The Gemasolar 19.9-MW Concentrated Solar Power system is a “power tower” plant, consisting of an array of 2,650 heliostats (mirrors) that aim solar radiation at the top of a 140-m (450-ft) central tower. The radiation heats molten salts that circulate inside the tower to temperatures of more than 500 °C (932 °F). The hot molten salts are then stored in tanks that are specially designed to maintain the high temperatures. This cutting-edge heat storage system enables the power plant to run steam turbines and generate electricity for up to 15 hours without any incoming solar radiation.

Is it perfect?  Of course not.  Facilities like this will take a large amount of space and will most likely be relegated to very rural areas.  This in turn will lead to problems of transporting the energy to urban areas of high usage, another issue that has dogged the renewable energy sector for quite awhile.  In addition there is still the issue of inclement weather (multiple cloudy days in a row) which will be particularly devastating to a system that relies on heat production.

All of these issues will likely relegate this kind of technology to a niche market.  It will require a climate that provides long periods of uninterrupted sun, large amounts of open space and well designed energy grid.  But what if those conditions are met, as they are in places like Spain, the southwest United States or (to a lesser extent) Northern Africa.  In the right market this kind of technology could be what pushes solar energy into the lead.

The fact that this will not be the panacea to the global energy problem but rather a small part of a larger energy portfolio is not a criticism.  Anyone who has seriously looked at the issue realizes that our future energy system will be comprised of many different technologies, each with their own strengths and weaknesses.  A combination of smart technology, a commitment to energy conservation and a societal shift towards lower population and less conspicuous consumption will be what takes us into the future.

Aubrey De Grey In The News Again July 6, 2011

Posted by Metabiological in Longevity.
Tags: , , ,
2 comments

Despite the fact that the actual word isn’t something you’ll see all that much transhumanism is steadily marching into the mainstream.  Case in point; Aubrey de Grey has an article up about him, detailing both his current anti-aging research and his belief that very soon we will create a world without death.

A biomedical gerontologist and chief scientist of a foundation dedicated to longevity research, de Grey reckons that within his own lifetime doctors could have all the tools they need to “cure” aging — banishing diseases that come with it and extending life indefinitely.

“I’d say we have a 50/50 chance of bringing aging under what I’d call a decisive level of medical control within the next 25 years or so,” de Grey said in an interview before delivering a lecture at Britain’s Royal Institution academy of science.

Okay first things first.  I like Aubrey de Grey.  There was a time in my life when I wanted to make my way into anti-aging science largely because of his ideas and while I now focus my efforts on a very different field I still regard him as both a vanguard of transhumanism and a great opponent of the inevitability of death.  On top of that his SENS approach is one of the few approaches I’ve seen that seems like it has a fair chance in hell of working in the near future.

That being said I think he is wildly over-optimistic in his time frame.  Partly this is the result of futurists just having a bad track record overall of successfully predicting the future.  Partly this is wish fulfilment in action, with all these wonderful developments happening just in time to save de Grey and his generation (Ray Kurzweil has been accused of the same thing).   Finally,  it’s almost certainly partly the result of a good marketing strategy.  People tend to become a lot more motivated when you tell them that truly wonderful things are just around the corner, if only they’d donate a little more money or give a little more support to the cause.

My problem lies with the concept of the longevity escape velocity.  De Grey is quite fond of saying things like, “we will be able to cure the things 150 year olds die of before there are any 150 year olds.”  On the one hand I can see the reasoning behind the idea that rapidly advancing medical technologies will allow us to stay one step ahead of the Grim Reaper.  On the other hand that whole idea is assuming that Kurzweil’s “Law of Accelerating Returns” (which isn’t actually law) applies not only to information technologies but to any form of technological progress.

In addition I take issue with the idea that we will be able to find cures for ailments before said ailments have presented themselves.  The improved predictive ability that will come with developments in synthetic intelligence coupled with our ever growing knowledge of the causes of aging and decrepitude may give us some ability to head-off certain problems before they begin to appear.  But even the mightiest SI’s will not be oracles and it seems to me that many of the potential problems that will confront the super-old will only become apparent when people start dropping dead.

I suppose we’ll find out in a few decades or so who is right and who is wrong.  And pride be damned, I hope I’m wrong.

Sea Urchin Body One Giant Eye July 4, 2011

Posted by Metabiological in Science.
Tags: ,
add a comment

Awesome.  Researchers have discovered that the common purple sea urchin, despite lacking anything we might usually call eyes, is able to see by utilizing it’s entire body as a large compound eye.

Previous studies of sea urchins have shown that they have a large number of genes linked to the development of the retina, which is the light-sensitive tissue in the human eye. This means that sea urchins have several genes that are coded for a widely occurring eye protein, opsin.

The research group behind the study showed that the photoreceptors seem to be located on the tip and base of the tube feet that are found all over the sea urchin’s body and are used to move.

Seriously, how cool is that?  An organism using it’s entire body as one giant eye.  That’s like something out of a shlockey, low-budget monster movie.  This is the part where we discover that sea urchins are invading the land and hunting down innocent humans with their giant, body eyes.