Anthropogenic Mass Extinction Thread

[Warren Platts]

I would have thought that the very idea that the planet is currently undergoing a mass extinction event that rivals in magnitude some of the major mass extinctions in prehistory is such a commonplace that it hardly bears repeating. But apparently, there is at least one person who likes to post here (Neverfly) who would deny that proposition. So rather than hijack that other thread, I created this one.

That the planet is currently undergoing a mass extinction event that rivals in magnitude some of the major mass extinctions in prehistory is the mainstream view. Cf. Harvard biologist E. O. Wilson's "Only Humans Can Halt the Worst Wave of Extinction Since the Dinosaurs Died":

The world's fauna and flora are paying the price of humanity's population growth. The levy may be acceptable to those who put immediate human concerns above all else. But it should be borne in mind that we are destroying part of the Creation, thereby depriving all future generations of what we ourselves were bequeathed. The ongoing loss in biodiversity is the greatest since the end of the Mesozoic era 65 million years ago. At that time, by current scientific consensus, the impact of one or more giant meteorites darkened the atmosphere, altered much of earth's climate and extinguished the dinosaurs. Thus began the next stage of evolution, the Cenozoic era or Age of Mammals. The extinction spasm we are now inflicting can be moderated if we choose. If not, the next century will see the closing of the Cenozoic era and the start of a new one characterized by biological impoverishment. It might appropriately be called the Eremozoic era, the Age of Loneliness. (my emphasis)

Be it resolved: The ongoing loss in biodiversity is the greatest since the end of the Mesozoic era 65 million years ago.

[jlhredshift]

The link is a call for donations.

[Warren Platts]

So? Doesn't the existence of widespread anthropogenic extinction also imply a call to action: that we ought to strive to minimize future anthropogenic extinctions?

[Swift]

The link is a call for donations.

I took a look and the direct link is an essay by E.O. Wilson, a very well known biologist, about the issue. At the bottom of that webpage are links to not-for-profit advocacy groups. I have no problem with the link to the essay.

Let's keep this thread to the science of the issue at hand. It is politics free at the moment - let's keep it that way.

[geonuc]

Be it resolved: The ongoing loss in biodiversity is the greatest since the end of the Mesozoic era 65 million years ago.

Well, it can certainly be resolved that that is the position of Professor Wilson, but is it really the mainstream?

For the purposes of ranking, how do you define the severity of an extinction event? By loss of species? Genera? Bulk numbers of critters? Wilson refers to species loss in his article, but I seem to recall learning that isn't such a great measure.

I don't know. But I do know that the linked article is not persuasive on it's own. It reads like a shrill opinion piece, not a summary of the author's scientific conclusions.

[Neverfly]

I would have thought that the very idea that the planet is currently undergoing a mass extinction event that rivals in magnitude some of the major mass extinctions in prehistory is such a commonplace that it hardly bears repeating. But apparently, there is at least one person who likes to post here (Neverfly) who would deny that proposition.

Stay accurate.
I never denied it. I asked you to support it.
You claimed:

Originally Posted by Warren Platts:
We are in the midst of the worse mass extinction since the end of the Cretaceous.

My reply:

Any citations to support this claim?

If you can support the claim, can you demonstrate that the mass extinction is a direct result of technology?

You then beat around the bush, told me to take your word, refused to provide cites... it took over Five Posts from you to finally get you to post a citation.
One of them, you posted a link to a book online- giving no reference to where to read in the book to support your claim.
I searched the book and found it refuted your claim.


Now, after enough obfuscating, beating around the bush and handwaiving, you have sufficiently created enough confusion to sheild yourself.

That the planet is currently undergoing a mass extinction event that rivals in magnitude some of the major mass extinctions in prehistory is the mainstream view.

I'm following you Warren.

We may be in the middle of the worst mass extinction. We may not be.
From all your jumping around, I have no idea if you can say we are or say we are not.
Stop changing your claim.
Stop obfuscating.

Show support that Science has caused the worst Mass Extinction since the end of the Cretaceous.

THAT was your claim.

Demonstrate that we ARE in the midst of the worst Mass extinction since the Cretaceous and that it is Man Made.
Demonstrate that it is not transitional.
Demonstrate that it was not natural factors.

ETA: As a side note:
http://www.bautforum.com/1582441-post12.html
It's not unusual for me to comment harshly on human cruelty.
This includes the destruction of millions of cattle for fear of mad cow disease.
The ignorant hunting of sharks and mountain lions.
I have been very outspoken on this throughout the board during my stay.

[captain swoop]

If this looks like the claim is going ATM then we will move it.

[mugaliens]

That the planet is currently undergoing a mass extinction event that rivals in magnitude some of the major mass extinctions in prehistory is the mainstream view.

That's quite sad.

Cf. Harvard biologist E. O. Wilson's "Only Humans Can Halt the Worst Wave of Extinction Since the Dinosaurs Died":

The ongoing loss in biodiversity is the greatest since the end of the Mesozoic era 65 million years ago.

Be it resolved: The ongoing loss in biodiversity is the greatest since the end of the Mesozoic era 65 million years ago.

Uh, a little mainstream perspective, please!

And no, it most certainly is not, mainstream, as approximately 40 million years ago we had an event that resulted in more than 10% genus extinction intensity, and the mean extinction intensity has steadily fallen from approximately 5% to around 2% over the last 500 million years, with at least a 2% variation over any period within the last 50 million years.

That's mainstream.

More importantly are the measures of bio-diversity, which involves far more than the simplistic and least accurate "species richness" index. Indices such as the Simpson index and the Shannon index, the latter of which was designed to measure the diversity of information in general, not just species.

The Simpson index was designed to measure biodiversity, but it's a simple statistical tool and merely represents the probability that two randomly selected individuals in the habitat below to the same species. The problem is that with lower numbers of species, it produces a higher, not a lower index, which often confuses some people.

The key to this arguement is three-fold:

First, corrected for sampling artifacts, modern biodiversity is much the same as biodiversity 300 million years ago and all periods in between. Serious (>30%) mass extinction events have hit us three times since then, immediately followed by rapid rebounds. Thus, even massive extinctions result in rapid recoveries. Life finds a way...

Second, estimates of the present macroscopic species vary from 2 million to 100 million species, with most likely numbers falling around 13-14 million species. Thus, with so much variability in the estimates, and that's for today's, current data, not that of, say, 65 million years ago, concrete conclusions are highly suspect.

Third, the vast majority (>80%) of modern species are arthropods, which includes all insects, arachnids, and crustaceans.

Fourth, as icky as this sounds to modern westerners, most arthropods are fit for, and have been a part of, and remain a part of widespread human consumption. Yes, they're a major world food source, are as nutricious as beef, and are eaten both raw and cooked around the globe.

Fifth, many arthrapods that are not considered suitable for consumption are considered pests, and have been widely eradicated by means ranging from the heel of one's boot to vast insecticide spraying campaigns.

Thus, given the human population explosion from 800 million in 1750 to 7 billion in 2008, is this really so difficult a stretch to realize there would be a corresponding reduction in a principle component of the both world's food supply as well as it's #1 category of pests?



However, in Warren's defense, diodiversity estimates do distinguish between arthrapodia and other phylum. However, the vast majority of literature supporting biodiversity scare tactics very wrongly highlights key species, such as the spotted owl, redwoods, etc. That is grossly misleading, as literally thousands of species become extinct each and every year, and that's due to natural causes, not human causes.

If this looks like the claim is going ATM then we will move it.

I think the premise is a bit over the top, but there's been well-grounded thoughts, so this is a good place to continue to interject solid scientific discussion, rather than sweeping it under the ATM and CT mats.

[korjik]

I think that the idea is that the unprecedented mobility of humanity has caused alot of mixing of different habitats, creating alot of invasive species, creating alot of inadvertant extinctions.

I dunno whether the actual amount of extinctions hits the level of a mass event tho.

[DrWho]

It's undeniable that habitat loss is the primary source of species extinction, along with species specific over harvesting. Most of the world's fisheries are on the verge of collapse and great swathes of rain forests are being cleared on a daily basis. With increasing populations, there will be increased habitat loss. None of this is controversial. Whether you wish to compare this process to previous extinction events and over what timescales and how you choose to label it, is open to debate, of course.

[Delvo]

literally thousands of species become extinct each and every year

How was this determined?

For such a thing to actually be happening would require that most of the species that it happens to are hard to detect & measure and have not yet been studied or even observed. But then, how do we know they were there before at all, and how do we know they're not anymore? And then, with that information established from living examples, not fossils, how can it be compared to information on species known only from fossils, not living examples?

[DrWho]

For such a thing to actually be happening would require that most of the species that it happens to are hard to detect & measure and have not yet been studied or even observed. But then, how do we know they were there before at all, and how do we know they're not anymore?

By some estimates, more than 200,000 acres of rainforest are burned every day. That equates to some 78 million acres lost every year. What do you think will happen to all the species occupying that ecosystem?

[korjik]

By some estimates, more than 200,000 acres of rainforest are burned every day. That equates to some 78 million acres lost every year. What do you think will happen to all the species occupying that ecosystem?

you do realize that 78 million acres is an area the size of New Mexico every year? That would be the size of the USA in 31 years, or Brazil in 27 years?

[DrWho]

you do realize that 78 million acres is an area the size of New Mexico every year? That would be the size of the USA in 31 years, or Brazil in 27 years?

Yes, it's a lot.

Here are some examples:
Peru 1.
Peru 2.
Peru 3.
Brazil 1
Brazil 2.
Brazil 3.

[Ara Pacis]

To put this into perspective, what is the current rate of species creation?

I recall reading about speciation a few years back with regards to some rodent living on islands on the amazonian basin. Apparently, changes in channel flow create islands that last long enough to prevent intermixing and the decendents of the same rodent become different enough to be unable to mate. Instant new species. But, are they so different that we lose some genetically important "biodiversity" if one of them overtakes the other?

[Warren Platts]

Well, it can certainly be resolved that that is the position of Professor Wilson, but is it really the mainstream?

Yes. Professor Wilson of Harvard is about as mainstream as it gets.

For the purposes of ranking, how do you define the severity of an extinction event? By loss of species? Genera? Bulk numbers of critters? Wilson refers to species loss in his article, but I seem to recall learning that isn't such a great measure.

Biodiversity is measured at all levels, from the extent of genetic variation within a population to entire kingdoms. Bulk numbers of critters not so much. Past studies of mass extinctions have tended to focus on families and genera, but that's mainly because it is hard to identify individual species in fossils that are hundreds of millions of years old.

I don't know. But I do know that the linked article is not persuasive on it's own. It reads like a shrill opinion piece, not a summary of the author's scientific conclusions.

There's a couple of things going on. Unless you've actually worked in the biodiversity business, or otherwise have a direct personal interest, you'll have a hard time understanding how upset people can get when "their" study population goes extinct. I've had it happen to me. Since then, I've had to disengage; I just can't worry about it too much anymore. My cortisol levels can't handle it.

I never denied it. I asked you to support it.

OK sorry about that. I didn't realize that you're just ingenuously curious and desirous of learning something new.

Demonstrate that we ARE in the midst of the worst Mass extinction since the Cretaceous and that it is Man Made.

Measuring extinction rates is difficult. But, for example, at least 1/3 of all amphibians have experienced drastic declines in population numbers over recent years and are considered endangered. I think that's pretty bad. Here's the PNAS paper link again.

Human activities are associated directly or indirectly with nearly every aspect of the current extinction spasm. The sheer magnitude of the human population has profound implications because of the demands placed on the environment. Population growth, which has increased so dramatically since industrialization, is connected to nearly every aspect of the current extinction event.

Thus WRT science as one cause, the syllogism goes something like:

science ---> industrialization ---> population growth ---> mass extinction

This is not to say those arrows indicate logical implication nor that science cannot be harnessed for the benefit of biodiversity. Heck, there's a brand new science that does that that's formed within your lifetime: conservation biology. But I think that the idea that science has historically played at least an indirect role in the current extinction spasm is noncontroversial.

Demonstrate that it is not transitional.

I don't know what you mean by "transitional".

Demonstrate that it was not natural factors.

To take but one example, the Nile Perch was intentionally introduced into Lake Victoria. Now they can't find half of the 400 fish species that were documented there. You want to deny that effect was not human caused, go ahead, but you will have the burden of proof, and it will be up to you to provide evidence for once.

you posted a link to a book online- giving no reference to where to read in the book to support your claim.
I searched the book and found it refuted your claim.

I am quite certain you took that out of context.

Uh, a little mainstream perspective, please!

And no, it most certainly is not, mainstream, as approximately 40 million years ago we had an event that resulted in more than 10% genus extinction intensity, and the mean extinction intensity has steadily fallen from approximately 5% to around 2% over the last 500 million years, with at least a 2% variation over any period within the last 50 million years.

That's mainstream.

One wikipedia chart whose axes are not even labeled doesn't prove anything. And I can't make heads or tails out of the percentages you throw around: certainly it is not the case that 2% to 5% of species have gone extinct in any given 50 million year period.

More importantly are the measures of bio-diversity, which involves far more than the simplistic and least accurate "species richness" index.

I wouldn't call species richness an inaccurate measure of biodiversity. It is what it is. As such, it explicitly ignores intraspecific biodiversity, which is very important, and worth of conservation efforts. Nevertheless, when you have a lake that has 14 endemic species at t=1 and 3 species t=2, I call that a real pattern.

Indices such as the Simpson index and the Shannon index, the latter of which was designed to measure the diversity of information in general, not just species.

This is rather beside the point.

Second, estimates of the present macroscopic species vary from 2 million to 100 million species, with most likely numbers falling around 13-14 million species. Thus, with so much variability in the estimates, and that's for today's, current data, not that of, say, 65 million years ago, concrete conclusions are highly suspect.

This is more to the point. Estimating the number of species is not an exact science. Heck, defining what a species is is not an exact science. But to deny that modern humans have caused a massive increase in extinction rates over and above the natural background levels is in the same zone as Apollo hoaxers.

First, corrected for sampling artifacts, modern biodiversity is much the same as biodiversity 300 million years ago and all periods in between.

This is just false. E.g., angiosperms (flowering plants) did not exist 300 million years ago. So it certainly is not plants that you are referring to.

Serious (>30%) mass extinction events have hit us three times since then, immediately followed by rapid rebounds. Thus, even massive extinctions result in rapid recoveries. Life finds a way...

Oh brother. . . . You need to understand that geologists think of events happening within a few million years to be "rapid". But for our political purposes, a million years is not "rapid".

Fourth, as icky as this sounds to modern westerners, most arthropods are fit for, and have been a part of, and remain a part of widespread human consumption. Yes, they're a major world food source, are as nutricious as beef, and are eaten both raw and cooked around the globe.

I enjoy my shrimp, crab, or lobster as much as anyone, though it is not exactly kosher. Your point is?

Thus, given the human population explosion from 800 million in 1750 to 7 billion in 2008, is this really so difficult a stretch to realize there would be a corresponding reduction in a principle component of the both world's food supply as well as it's #1 category of pests?

Most extinctions result not from overharvesting or overt attempts at extermination (although that can happen): it happens mainly because of habitat destruction and introduced organisms.

the vast majority of literature supporting biodiversity scare tactics very wrongly highlights key species, such as the spotted owl, redwoods, etc. That is grossly misleading, as literally thousands of species become extinct each and every year, and that's due to natural causes, not human causes.

There is nothing wrong with highlighting key species, as long as it is recognized that such key species represent the tip of the iceberg. What is grossly misleading is your suggestion that most extinctions are not human-caused. In fact, documented cases of "natural" extinctions in modern times are extremely rare. I can think of maybe one or two.

rather than sweeping it under the ATM and CT mats.

Yes. Thank you.

I dunno whether the actual amount of extinctions hits the level of a mass event tho.

If all traces of human civilization magically disappeared, the mass extinction recorded in the fossil record would would still mark our existence.

[jlhredshift]

.....our existence.

I am in favor of that.

[geonuc]

Yes. Professor Wilson of Harvard is about as mainstream as it gets.

Perhaps he is. But to call an idea or hypothesis mainstream generally involves more people, don't you think? Perhaps a majority of learned scholars in the field. Prof. Wilson is but one person.

[Ara Pacis]

How many species would be dying off from natural climate change due to the interglacial if we weren't here?

[captain swoop]

Like Mammoths you mean?

[Ara Pacis]

Like Mammoths you mean?

Sure. Although some conjecture that an impact in North America might have helped kill them off.

[Neverfly]

OK sorry about that. I didn't realize that you're just ingenuously curious and desirous of learning something new.

My curiosity is not as relevant as you making bold claims in order to support a point and then failing to support your claims.

My lack of denial is based on uncertainty on my part as to whether or not your claims are true.

To take but one example, the Nile Perch was intentionally introduced into Lake Victoria. Now they can't find half of the 400 fish species that were documented there. You want to deny that effect was not human caused, go ahead, but you will have the burden of proof, and it will be up to you to provide evidence for once.

Again- I am not denying.
I am asking you to support your claims.

This example is an excellent example of human interference. However, humans are part of the ecology, too. Plants and animals have been interfering in eachothers evolution since life began.

Support your claim that we are suffering the Worst Mass Extinction since the Cretaceous.

[Warren Platts]

This example is an excellent example of human interference. However, humans are part of the ecology, too. Plants and animals have been interfering in each others evolution since life began.

How does it feel to be an apologist for needless human-caused extinctions, while having to resort to such lame, illogical justifications? Since when have humans modeled their ethics after what happens in nature?

Support your claim that we are suffering the Worst Mass Extinction since the Cretaceous.

When you've read the PNAS paper I've cited at least twice--it's quite short--please get back to me.

[Neverfly]

How does it feel to be an apologist for needless human-caused extinctions, while having to resort to such lame, illogical justifications? Since when have humans modeled their ethics after what happens in nature?

When you've read the PNAS paper I've cited at least twice--it's quite short--please get back to me.

To quote BigDon, now I need the Heimlich maneuver...

[Warren Platts]

See, providing the citations you ask for is like pouring water on the back of a duck. It results in nothing.

[Neverfly]

See, providing the citations you ask for is like pouring water on the back of a duck. It results in nothing.

No.
My response was to your putting so many words in my mouth.

As far as your cite- I am still muddling through it. However, it appears ( I may be wrong) that mugaliens replied to you on it.

[Maha Vailo]

So what are you suggesting we do about this (if this is true)? What could be done to keep people from ruining and destroying habitats?

- Maha Vailo

[Warren Platts]

Grant special protections to biodiversity hotspots. These are typically islands or island-like habitats on continents (freshwater ecosystems, mountaintops). Preventing the building of roads into the world's last roadless areas is also good. Buying up habitat before developers get a hold of it.

What you don't want to do is resort to zoos, or orbital habitats (as some have suggested in other threads--that is as crazy as it sounds). The main idea is to preserve biodiversity before it gets to the endangered stage and requires heroic management efforts to prevent an impending extinction.

[GOURDHEAD]

The set of products of evolution continues to be a many splendored, as well as a many splintered, thing!

[jlhredshift]

On mammoths David J. Meltzer in First Peoples in a New World: Colonizing Ice Age America