Biologist warn of early stages of Earth’s sixth mass extinction event

Jul 31, 2014

By ScienceDaily

The planet’s current biodiversity, the product of 3.5 billion years of evolutionary trial and error, is the highest in the history of life. But it may be reaching a tipping point.

In a new review of scientific literature and analysis of data published in Science, an international team of scientists cautions that the loss and decline of animals is contributing to what appears to be the early days of the planet’s sixth mass biological extinction event.

Since 1500, more than 320 terrestrial vertebrates have become extinct. Populations of the remaining species show a 25 percent average decline in abundance. The situation is similarly dire for invertebrate animal life.

And while previous extinctions have been driven by natural planetary transformations or catastrophic asteroid strikes, the current die-off can be associated to human activity, a situation that the lead author Rodolfo Dirzo, a professor of biology at Stanford, designates an era of “Anthropocene defaunation.”

Across vertebrates, 16 to 33 percent of all species are estimated to be globally threatened or endangered. Large animals — described as megafauna and including elephants, rhinoceroses, polar bears and countless other species worldwide — face the highest rate of decline, a trend that matches previous extinction events.

Larger animals tend to have lower population growth rates and produce fewer offspring. They need larger habitat areas to maintain viable populations. Their size and meat mass make them easier and more attractive hunting targets for humans.

Although these species represent a relatively low percentage of the animals at risk, their loss would have trickle-down effects that could shake the stability of other species and, in some cases, even human health.

For instance, previous experiments conducted in Kenya have isolated patches of land from megafauna such as zebras, giraffes and elephants, and observed how an ecosystem reacts to the removal of its largest species. Rather quickly, these areas become overwhelmed with rodents. Grass and shrubs increase and the rate of soil compaction decreases. Seeds and shelter become more easily available, and the risk of predation drops.

23 comments on “Biologist warn of early stages of Earth’s sixth mass extinction event

  • 1
    Nunbeliever says:

    Sadly the Wall Street bankers and the other corporate psychopaths largely responsible for most of the bad things happening in this world don’t give a shit as long as they have access to expensive whores, dinners and country clubs. That’s what humanity really is about. Vanity, vanity and more vanity. We deserve to go extinct. In fact, I can hardly wait for this pathetic species to vanish!



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  • 3
    NearlyNakedApe says:

    Sadly the Wall Street bankers and the other corporate psychopaths largely responsible for most of the bad things happening in this world don’t give a shit as long as they have access to expensive whores, dinners and country clubs…

    … and Quaaludes. Don’t forget Quaaludes….



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  • 5
    Nunbeliever says:

    Let’s hand over the keys to the women. Men, clearly have failed as leaders of this planet. We should step aside and let the other gender give it a try. I mean, they can hardly fuck this planet up more than we have…



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  • What a silly article in that it starts with one sentence, follows immediately by questioning that sentence, and then sets about proving it absolute nonsense…



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  • I can hardly wait for this pathetic species to vanish!

    Sad but true. I concur with your sentiments, and endorse Bonnie’s run for world leader.

    The extinction of the animals of the planet are the collateral damage of Wall Streets greed. Ethics? Morality?

    There are rules of nature that can’t be broken. The speed of light. The 2nd law of thermodynamics. Close systems have limits.

    If you put one sheep in Wembley Stadium with a water supply, it would live a full natural life. Two sheep? No problem. 10 sheep?? How about 100 sheep. Or 1000 sheep. At that level, you’ve exceeded the limits of the closed system. Everything will go fine until the grass starts running out. The population will rapidly crash and die. It may kill all of the sheep or it may get to a level where the number of sheep left, will live a desperate existence on the edge of starvation, within the limit of the closed system. These are fixed rules of closed systems and animal population plagues.

    The graph that describes animal plagues, exactly mirrors current human population growth. That graph, ALWAYS reaches a peak, then goes through a mass extinction as the population plummets back to a sustainable level. What makes me desperately sad, is that my grandsons are likely to be part of that crash. What makes me very angry is that it is self inflicted by those psychopaths named in NunBeliever’s post.

    The graph at this site, mid way down shows what I am talking about.

    http://sustainable.7gen.com/2011/10/human-population-on-this-planet-reaches.html

    Various estimates exist, but a mean suggests that the planet can support around 1 billion, if we live a sustainable lifestyle. We’ve hit 7 billion, heading for 9-12 billion. And those persons of suspect parentage that believe in a free market are the people to blame. I for one don’t want my grand children to live, “will live a desperate existence on the edge of starvation,

    Global involuntary euthanasia.



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  • We should not overlook the input of inane alternate remedies in bringing pressure to bear on the viability of a species. I’m thinking specifically of the plight of the rhino, hunted to extinction due to superstitious reasoning by the the practitioners of traditional ‘cures’. The result of such faulty reasoning has put the price of rhino horn above the price of gold! The ground rhino horn is a supposed cure for cancer! As if?

    Of course species loss is more likely due to the sheer weight of our numbers and impact of our lifestyle as has already been stated, but I react strongly to scenes showing the callous disregard towards the lives of species other than our own.



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  • @Nitya. I don’t know about you Nitya, but I think this is a far more important issue than the virulent discussions over the Twitter Storm… But that’s just me.

    Did you watch the program on ABC on the Rhino’s. There should be a co UN / Govt. sponsored saturation media campaign throughout China and S.E. Asia on the fact that Rhino horn does nothing. And bear bile, tiger spleen and every other exotic endangered animal so Asian men can sustain an erection. Maybe we should be Viagra in the water supply. As the ranger said, it will take years to change the culture, but it must start now. Shame the users. Ridicule them. Make them social pariahs. Bring public and government pressure to bare to act strongly on these issues.



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  • Hi David R. I have to agree with you re the Twitter Storm. So many comments by so many unfamiliar user names!
    I’m fairly sure that I saw the program mentioned as I rarely miss documentaries about these topics. A program last week featured the subject of rhino hunting complete with grisly images of dead rhino having had the horn hacked off ( often when the animal was still alive). These atrocities happen because of the twin evils of ignorance and superstition! The market is driven by ignorant purchasers.
    Most people are happy to turn a blind eye to quack remedies as they seem to be harmless enough; what does it matter if the ailment is merely responding to the placebo effect? I think it does matter. The herbal remedy for one is ground rhino horn for the other. It’s all based on ignorance and that does matter!



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  • 11
    Steve_M says:

    I think you hit the nail on the head there regarding the major cause of the problem – ie unsustainable overpopulation of the planet by humans. I’m just not sure how you conclude solely that persons of suspect parentage that believe in a free market are the people to blame for the current human population crisis. Particularly when you look geographically, geopolitically and georeligiously (if that’s a word!) at the areas where unsustainable human population growth and associated habitat destruction are at their worst.



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  • John Jul 31, 2014 at 6:23 pm

    What a silly article in that it starts with one sentence,

    The first part of which is solidly supported by scientific evidence. …..

    @OP – The planet’s current biodiversity, the product of 3.5 billion years of evolutionary trial and error,

    …and is accurate both in the approximate period of biological evolution on Earth, and that there is currently a mass extinction in progress.

    @John – follows immediately by questioning that sentence, and then sets about proving it absolute nonsense…

    The claim that present biodiversity is the highest in existence, is very dubious. . . . . .

    @OP – is the highest in the history of life. But it may be reaching a tipping point.

    …. . . but the there are both habitat and climatic tipping points which could rapidly escalate extinctions.



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  • 14
    Robert says:

    I went looking for it couldn’t find it. But there is a middle ground cure for the rhino horn problem. Rhinos regularly lose part of the horn due to competition, rubbing against trees etc. It grows back as long as it’s not cut below a certain mark. Many in Africa who are trying to raise more rhinos for release into the wild will cut the horn off above the point where the animal would suffer from blood loss. This keeps poachers off their land since there is no horns for them to harvest. One guy who has been collecting the cut horns on his ranch was upset about the laws. You can’t sell or transport a horn without documentation that you had a permit to shoot and kill a rhino. But he has hundreds of horns, some of his rhinos have been dehorned several times and he doesn’t allow hunters with permits on his property. A virtual gold mine that if it hit the market would drop the price for horns around the world.

    Maybe we should fix this problem by flooding the market with safely removed rhino horns to the point that the price drops to levels that poachers won’t bother. You could literally save the rhinos over night. It would only take the change of 1 law. Truth is I think the government’s are getting a kick back to turn the blind eye to this because I’ve been hearing about this for at least 10 years.

    Once the price drops the number of lower class people who get access and when hundreds start calling it a rip off people won’t be so desperate to get them. Heh if I remember right the main ingredient in rhino horns is keratin? It’s basically a dense pack of hair that grows into a horn. But I might be wrong about that… still there’s lots of sources of the ingredients in the horn, we could just gather that, bleach it in color, and sell it in powder form… they won’t be able to tell the difference lol.



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  • Robert Aug 1, 2014 at 3:06 pm

    I went looking for it couldn’t find it. But there is a middle ground cure for the rhino horn problem. Rhinos regularly lose part of the horn due to competition, rubbing against trees etc. It grows back as long as it’s not cut below a certain mark. Many in Africa who are trying to raise more rhinos for release into the wild will cut the horn off above the point where the animal would suffer from blood loss. This keeps poachers off their land since there is no horns for them to harvest. One guy who has been collecting the cut horns on his ranch was upset about the laws. You can’t sell or transport a horn without documentation that you had a permit to shoot and kill a rhino.

    First of all the use or rhino horn in so-called medicines is pure quackery, so it is a con which is causing poaching and damaging wild life.

    The issue of sales is similar to elephant tusks. Tusks are burned not because they would be useless or valueless, but because any sales, provide a cover for black markets and encourage the extreme damage caused by poachers.
    The marketing of the nutritionally valueless shark-fin soup is a similar case of snobbery or quackery causing huge ecological damage.



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  • Hi Robert. Many of the rhinos shown on my ‘rhino’ program had been partially de-horned in an effort to discourage poachers. Unfortunately this measure was unsuccessful as desperate hunters would still kill the animal and take the remaining horn. The hunters received the meager sum of $200 per horn. Of course the price escalated along the chain as people took their cut. Astounding when you think of it. All that bloodshed for keratin! A substance with as much worth as fingernail clippings!

    I have also wondered why elephants were not de-tusked as soon as possible and sharks de-finned (ha ha). Perhaps shaming users would be a suitable form of attack on those generating the market for such products. I know the Japanese use ‘shaming’ to good effect as a measure of social control. It works! They ( in Japan) have a very law-abiding citizenry.

    I suppose the mass extinction event discussed in the article is not relating to the few species threatened by poachers but instead by the 7 billion plus hungry mouths to feed and sustain. We are contributing as well, simply by being on the planet and enjoying the resources we have available to us in our developed world lifestyle.



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  • 17
    Robert says:

    But the point is there is a legal market as in those who purchase expensive conservation permits to kill reserve rhinos. The documents provided allow for the transfer of the horn out of the countries of origin and then to be sold legally anywhere. Even in the USA. The funny thing is they almost always if sold get moved into the black markets because of the price so high. I think your desire to prove it’s quackery, which I agree they are, is clouding the fact that there’s a better way to harvest tusks of elephants and horns of rhinos that would instantly kill the need for poaching. Which would also end black markets of the products. Besides if seen all sorts of interesting things made of both item mentioned. And to deem them bad because they are killing the animals, but refusing the replacement of kills with safe harvesting. Why? Cause you don’t like their beliefs? Well beliefs don’t change without education, but when they themselves are spending billions on this… what would happen when that money suddenly is free to spend else where while we are pouring information in? We all know that one of the greatest influences of the current trend of losing superstitions and backward beliefs is also the passing of the elder generations being replaced with the younger more educated generations. Really I’m just pointing out you can cut one problem which is drawing interest so you can free their minds and their finances to one in a better direction. Also yeah that cigars remark maybe we should be advertising that for to the impotent in asia.

    I think you misunderstand the point I was making. Not every problem can be solved by saying stop it’s not right, that’s superstition isn’t true. Sometimes you have to reach a compromise that improves your situation, until you can put in place the better solution efectively.



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  • Robert Aug 1, 2014 at 4:47 pm

    But the point is there is a legal market as in those who purchase expensive conservation permits to kill reserve rhinos.

    This is merely a reflection of corrupt governments who don’t give a damn about wildlife or ecology. Many of them don’t give a damn about their own people either.

    The same sort of thing happens with illegal logging. Illegal timber acquires certificates and legalising credentials, from corrupt governments or corrupt officials, whose main concern is taking a personal profit. – frequently tiny in comparison to the damage they are doing.
    Strong international enforcement is the best effective answer. – As with ivory – seize illegal stocks and burn them, so the traders make heavy losses. – and arrest and prosecute the poachers.
    Without a black market, substitute materials will be progressively used.
    http://edition.cnn.com/2014/05/16/world/asia/hong-kong-ivory-burn/

    Hong Kong holds world’s largest ivory burn

    http://burntheivory.org/news/



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  • @Robert.
    No, I didn’t miss your point, but I probably became sidetracked by my own thoughts once I began to write. For that, I apologise.
    Establishing a legitimate marketplace for a desired product does not always solve the problem because the black marketeer is free to vary the price according to supply and demand (as with the sale of drugs, for example). They could just undercut the legitimate outlet. Even if a commercial harvesting centre were set up, I doubt demand could be met. It’s a very interesting proposition nonetheless. The more I think about it, the more feasible it sounds!
    I take your point regarding my judgement on the element of superstition as well. People are not jumping up and down in protest over jojoba oil or other magical elixirs said to cure all ills, make us beautiful and reduce the crime rate (joke).
    Government endorsed trading centres for the body parts of animals could send the message that these treatments are valid. What do you think? I tend to have an eye for an ideal world in which ignorance is a thing of the past. It will probably never happen and if it does, it certainly won’t be in my lifetime.

    .



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  • @Alan4Discussion.
    These corrupt governments are generally found in regions with a very low standard of living as well. The infrastructure of these places is either abysmal or nonexistent and people will resort to anything in order to survive. It usually comes down to politics in the long run. When wealth is shared equitably throughout the community many problems right themselves. We are not let off the hook, however. Apparently Australia has a burgeoning market for rhino horn! Who would have thought?



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  • @Robert.

    Currently, only the very rich in East Asia can afford Rhino horn. If you lower the price, demand goes up, the middle class can afford the horn, …. You can complete the dots. Markets never solve any social problem.

    The only permanent solution to Rhino horn, elephant tusk, tiger testicles and captive bear bile farms is to destroy and decimate the myths associated with the quackery. I concur with Nitya. Shame. Social outcast. Education. Vast and sustained advertizing campaigns. Law enforcement. Rewards to people who report crimes and huge publicity of those informants receiving their new cars, houses and cash. Change the market in the market place and drive the price down by decimating the demand. No price incentive. No rhino poaching.

    You are talking about moving a cultural practice. This will take generations but it is the only permanent solution. My only hope is that there will still be some rhinos about to save if global warming and 12 billion humans don’t kill them off before.



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  • 22
    Nicholas says:

    Throughout the history of our species, an endless number of men have fought, and continue to fight, to stand up for what’s right and try to make the world a better place to live and I can’t help but feel that these types of generalizations do them a disservice.

    We make mistakes, not because we’re men, but because we are a clumsy animal that stumbled out of the african savannah and started wearing clothes and trying to comprehend complex social systems and continually emerging dynamics, and because so long as there exists opportunity for people to take advantage of other people, there will be those that seize and exploit that opportunity. The potential to cause or alleviate negative impacts on our world exists in all of us. Through our actions and our indifference.

    Making any sort of drastic positive changes to the world based on what already exists within is becoming exponentially more difficult as we go forward. We all have these quaint notions about what’s wrong with the world but fail to appreciate all the ways in which men and women, every day, are already working their asses off to make it better. Those kinds of people haven’t given up on us as a species.

    “We” haven’t failed… Any more than you are a sinner because a man named Adam failed god’s fruit test. We have operated precisely as the conditions fostered. We have become the only thing that we could have become based on the precise previous position of all relevant matter and energy influencing the development of our experiences. We are the product of everything that came before us.



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