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Holocene Sixth Mass Extinction Event In Progress


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February 5th 2009

 

*Note: Immediate Action Required!

 

As far back as the 1970's, several scientists tried to warn the world of an impending mass extinction event in progress.

 

Most people brushed this off as lunatic-fringe heresy and went on with their 'business as usual' self-centered and shallow attitudes.

 

By 1994, it was becoming obvious across the globe for general biological observers, to notice that a major cascading extinction was really taking place, and that something had to be done about it immediately.

 

Even average people could witness definitely strange changes in their own back-yard. Seasons came 30 days earlier with plants and trees producing 'different' structures as an ill omen of things to come.

 

Today we call this climate change and global warming with a giant question-mark toward another Ice Age.

 

This accelerated weather cycle is nonetheless severe, unpredictable, destructive and Earth-changing in its current form. Climate models are now predicting very unnatural probability weather events, that generate with little or no warning, appearing as thunderstorm development, then power-up to Cat 3 levels.

 

Ongoing discussions are in progress for upgrading current scales to Cat 6 and F-6 respectively.

 

Tree-trunk lightning: one strike per square foot and discharging for longer durations for each strike.

 

Is it possible that our atmosphere could become so electrically static charged, that someone could be electrocuted by discharging across a floor carpet or outside on a vehicle negative ground?

 

There have been 5 previous mass extinction events within the geologic record, and now this sixth one currently in progress may become far worse, than any of the previously set precedents.

 

It has been given the title: Holocene Sixth Mass Extinction Event: http://www.ucmp.berkeley.edu/quaternary/hol.html

 

Activists around the world are currently in a death-struggle for the survival of all endangered species, and I personally hope you will join in this fight, if you have not done so already!

 

Legally petition, protest, campaign, legislate and donate for 'safe' environmental control laws.

 

Become mentally and physically PROACTIVE, because the life that you may be saving could actually be your own!!!

 

Support all 'Animal Protection Rights' groups and movements for the voiceless billions.

 

This is the only rational reactive-response we have to engage, because the survival of the human-race is, and has always been very much participatory!

 

The patient is extremely sick and dying rapidly, but our action instead of inaction could possibly save the day --- Or at least to buy ourselves and our children some time!!! ---- (???) ----

 

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Holocene Sixth Mass Extinction:

 

American Museum of Natural History Press Release:

http://www.well.com/~davidu/amnh.html

 

The Pleistocene-Holocene Event - Sixth Great Extinction:

http://rewilding.org/thesixthgreatextinction.htm

 

Holocene Extinction Event - Wikipedia:

http://en.wikipedia.org/wiki/Holocene_mass_extinction

 

Mass Extinction Underway/Biodiversity Crisis/Global Species Loss: http://www.well.com/user/davidu/extinction.html

 

Animal Extinction: The Greatest Threat To Mankind - The Independent

http://www.independent.co.uk/environment/animal-extinction--the-greatest-threat-to-mankind-397939.html

 

***>The Sixth Extinction - ActionBioscience:

http://www.actionbioscience.org/newfrontiers/eldredge2.html

 

The Holocene Extinction Event - Are Humans Destroying the Planet's Web of Life? - Daily Galaxy:

http://www.dailygalaxy.com/my_weblog/2008/08/the-holocene-ex.html

 

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Activist's Section:

 

National Wildlife Federation: Action Headquarters - HQ NWF:

http://online.nwf.org/site/PageServer?pagename=Action_Headquarters

 

Why Save Endangered Species?:

http://www.endangeredspecie.com/Why_Save_.htm

 

Groups Fight To Save The Endangered Species Act - The Humane Society:

http://www.hsus.org/press_and_publications/press_releases/groups_fight_to_save_esa_121708.html

 

Save The Polar Bear - Center for Biological Diversity - Petition:

http://salsa.democracyinaction.org/o/2167/t/8257/petition.jsp?petition_KEY=1725

 

Endangered Species - Care2 Petitions:

http://www.care2.com/causes/endangered-species/petitions/

 

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Youtube Section:

 

Current Mass Extinction Video:

 

'Call of Life' Facing the Mass Extinction Trailer - Youtube:

 

Planet Mammals Face Mass Extinction:

 

General Extinction - Video Information:

 

Evolution - Extinction 1of6:

 

Evolution - Extinction 2of6:

 

Evolution - Extinction 3of6:

 

Evolution - Extinction 4of6:

 

Evolution - Extinction 5of6:

 

Evolution - Extinction 6of6:

 

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Signature: THE FIFTH KNIGHT'S NEWS

http://www.care2.com/news/member/510010530?sort=submitted

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There have been 5 previous mass extinction events within the geologic record, and now this sixth one currently in progress may become far worse, than any of the previously set precedents.

 

Sorry, but no. Statements like this are the reason people brush the whole issue of current extinctions off as alarmism.

 

The fact is, we could burn every drop of oil right now, releasing all of that greenhouse gas at once, and the effect would still *pale* in comparison to prior mass extinctions. In the Permian Catastrophe, 90% of life died. 90% And the fossil record is biased against rare species, so the actual total was probably much higher.

 

Mokele

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Whether or not it's "far worse" or whatever, would you say it's inaccurate to say that we are currently in a mass extinction? It might not be the same as previous ones because the mechanism is (presumably) different (ours being the result of the extremely rapid rise of a single out of control species that occupies and tends to radically change every ecosystem on Earth), but the effect would be comparable if trends continue, right? Was the rate of extinction 65mya faster than it is today?

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IIRC, we are indeed currently well above the baseline extinction rate, even accounting for biases in the fossil record, so this does qualify as a mass extinction.

 

My point was more that comparing it to the truly catastrophic extinctions like the KT event and the End-Permian event is ridiculous, and displays a serious lack of understanding about the scale of those events.

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The American Museum of Natural History conducted a survey of scientists, that a majority declare:

 

We are in the midst of the fastest growing mass extinction event within Earth's geologically recorded history. Crisis Poses Threat to Human Survival; Public Unaware of Danger!

 

http://www.amnh.org/museum/press/feature/biofact.html

 

C2NN recorded my submission article:

http://www.care2.com/news/member/510010530/1038485

 

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Signature: THE FIFTH KNIGHT'S NEWS:

http://www.care2.com/news/member/510010530?sort=submitted

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Yes, but how many of the tiny community of paleontologists who focus on extinctions declare this?

 

I'm being stubborn for a very good reason - overstating your claims results in listeners just discarding the whole message, even if the overstatement is a minor part of it.

 

Claims that this is the fastest are highly dubious. Imagine how this extinction would look if we only sampled 4 areas n the entire planet, 2 marine and 2 land. That's what we're looking at in the fossil record. Of course more species are going extinct now - 95%+ of past species left no fossil record at all, and so could disappear (or appear, or stay) without us ever knowing.

 

 

I fully agree that we are in a mass extinction of our own making. I just disagree about it's current and potential future magnitude with respect to prior mass extinctions.

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University of California - Santa Barbara (UCSB):

 

The Earth is currently in the midst of the sixth mass extinction of both plants and animals, with nearly 50 percent of all species disappearing, scientist say.

 

Current Mass Extinction Spurs Major Study of Which Plants to Save - University of California (UCSB):

 

http://www.ia.ucsb.edu/pa/display.aspx?pkey=1864

 

We cannot wait in inactive apathy, until only micro-organisms are crawling through the next bottle-neck!

 

We must do everything possible right now in order to minimize the estimated species to be lost.

 

Not enough has been accomplished in the 1960's, 1970's, 1980's, 1990's or to date!

 

Take action, rather than 'day-dreaming' on the keyboard!!!

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I'm being stubborn for a very good reason - overstating your claims results in listeners just discarding the whole message, even if the overstatement is a minor part of it.

Coffee stains on the tray tables.

 

"How can you trust the airplane maintenance when they can’t wipe the coffee stains off the flip trays?" (Tom Peters, "In Search of Excellence"). Sometimes a seemingly small thing such as coffee stains on the flip trays in an airplane can indeed derail the message. The airplane might well be very safe, or humans might well be causing significant harm to the natural environment, but all it takes is one seemingly unrelated item such as coffee stains or a grossly exaggerated claim of an ongoing mass extinction and the intended message is wiped out.

 

Claims that this is the fastest are highly dubious.

Particularly so since we do not yet know what caused these past mass extinction events or how truly widespread they were. The logical fallacy here is pretending that the average extinction rate we see in the biological record is the same as the instantaneous extinction rate we see now. We do not know what the peak instantaneous extinction rate was during the past mass extinction events.

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The problem here is credibility. In the OP The Fifth Knight links to this article;

http://www.actionbioscience.org/newfrontiers/eldredge2.html

 

The article states in part;

As long ago as 1993, Harvard biologist E.O. Wilson estimated that Earth is currently losing something on the order of 30,000 species per year

It's been 15 years since that estimate was made and if correct then 450,000 species have been lost.

 

Name 10.

 

I won't hold my breath.:rolleyes:

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He's mostly referring to undiscovered species, and species which we do not keep active tabs on. As such, your challenge to 'name ten' isn't really relevant, because just because we don't intimately recognise each and every extinction, estimates of biodiversity on the planet yield that high of an extinction rate.

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He's mostly referring to undiscovered species, and species which we do not keep active tabs on. As such, your challenge to 'name ten' isn't really relevant,

Riiiiiiiiigt. So the species we are watching haven't become extinct, it's only the ones we either aren't watching or haven't shown they exist.

 

I can see how asking for some evidence would be irrelevent. We can't let facts get in the way of a good guilt trip can we?

 

Yes, I am derisive of the concept of this "current great extinction".

 

How about some hard data?

 

Either that, or admit that all you have are guesses and speculation. Then we can move this thread to where it belongs.

 

None of the above is meant to imply that there haven't been extinctions due to man, but "Sixth Great Extinction"? Extraordinary claims require extraordinary evidence. Got anything?

 

Note that one of the OP links is to a petition to "Save the Polar Bears". This is despite the fact that their numbers have been growing for years. But where would the green guilt industry be without a plea to save the pretty animals?

Edited by JohnB
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Riiiiiiiiigt. So the species we are watching haven't become extinct, it's only the ones we either aren't watching or haven't shown they exist.

 

I can see how asking for some evidence would be irrelevent. We can't let facts get in the way of a good guilt trip can we?

 

Yes, I am derisive of the concept of this "current great extinction".

 

How about some hard data?

 

Either that, or admit that all you have are guesses and speculation. Then we can move this thread to where it belongs.

 

None of the above is meant to imply that there haven't been extinctions due to man, but "Sixth Great Extinction"? Extraordinary claims require extraordinary evidence. Got anything?

 

Oh come on, scientists extrapolate all the time. I think gravity exists in some place, and yet there is no probe of any kind there to measure it — is that a guess or speculation? If I do a test on a random population sample, is it just a guess or speculation that the results will hold, within statistical uncertainty, for a larger population?

 

We have documented extinction rates in regions where we have some ideas of species count and diversity. Why is extrapolating that to regions that have not been extensively documented being treated with such scorn?

 

http://www.pbs.org/wgbh/evolution/library/03/2/l_032_04.html

 

The typical rate of extinction differs for different groups of organisms. Mammals, for instance, have an average species "lifespan" from origination to extinction of about 1 million years, although some species persist for as long as 10 million years. There are about 5,000 known mammalian species alive at present. Given the average species lifespan for mammals, the background extinction rate for this group would be approximately one species lost every 200 years. Of course, this is an average rate -- the actual pattern of mammalian extinctions is likely to be somewhat uneven. Some centuries might see more than one mammalian extinction, and conversely, sometimes several centuries might pass without the loss of any mammal species. Yet the past 400 years have seen 89 mammalian extinctions, almost 45 times the predicted rate, and another 169 mammal species are listed as critically endangered.

 

http://www.sciencedaily.com/releases/2002/01/020109074801.htm

 

Some 2,000 species of Pacific Island birds (about 15 percent of the world total) have gone extinct since human colonization. Roughly 20 of the 297 known mussel and clam species and 40 of about 950 fishes have perished in North America in the last century.

 

Then consider the regions of the world that have not been extensively studied. The implication that these regions do not have the extensive biodiversity seen elsewhere is the extraordinary claim here.

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Oh come on, scientists extrapolate all the time.

Yes, they do. And I generally have no problem with this.

 

Here we have an extrapolation from an incomplete record compared to an extrapolation from an incomplete record followed by a declaration of disaster.

The implication that these regions do not have the extensive biodiversity seen elsewhere is the extraordinary claim here.

No, the claim is that we are in the midst of the "Sixth Great Extinction".

 

I find that claim extraordinary. specifically that this "Great Extinction" is on par with those known from the records.

 

I'm asking for proof.

 

So far all that has been presented is extrapolation and guesswork. Such things are not evidence.

 

If I were to extrapolate the number of asteroids we haven't seen and combined that with an extrapolation of the number that hit us each year that we don't know about and from this conclude that we will be wiped out in the next 50 to 100 years, would you accept the conclusion? Of course not.

 

You would ask for proof. Just as I am doing.

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No, the claim is that we are in the midst of the "Sixth Great Extinction".

 

I find that claim extraordinary. specifically that this "Great Extinction" is on par with those known from the records.

 

On par with what? The normal extinction rates? Or the other major extinctions? If it's the latter, what's the problem? If it's the former, how do you know what the prehistoric extinction rates are, if not from extrapolation?

 

 

I'm asking for proof.

 

So far all that has been presented is extrapolation and guesswork. Such things are not evidence.

 

The links I provided gave numbers of measured events. Evidence.

 

 

If I were to extrapolate the number of asteroids we haven't seen and combined that with an extrapolation of the number that hit us each year that we don't know about and from this conclude that we will be wiped out in the next 50 to 100 years, would you accept the conclusion? Of course not.

 

You would ask for proof. Just as I am doing.

 

You'd need to start with observing an increase in the number of meteorite strikes. If you saw that, then you might be able to do an extrapolation. Without that, the comparison is garbage — extinctions have been documented, contrary to your claim, and species (used to) exist in areas that have been cleared.

 

If you were to make an apt comparison, you would essentially be claiming that we can't measure the number of meteorite strikes on land and estimate the number that strike the ocean. It would be hard to take that claim seriously.

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On par with what? The normal extinction rates? Or the other major extinctions? If it's the latter, what's the problem? If it's the former, how do you know what the prehistoric extinction rates are, if not from extrapolation?

 

There's the rub, and I'd like to point out two things:

 

1) The fossil record can be used to calculate extinction (and speciation) rates, with appropriate cautions about preservation bias. The problem is, even for recent sub-mass-extinctions (such as the Great American Interchange about 2 million years ago), we're limited in resolution to thousand-year chunks of time, and for more distance events, the resolution is worse - if you just compared the species alive at the dawn of human civilization to those alive now, you'd have a 10x better temporal resolution than we have for the end-Cretaceous event. It's like trying to compare the slopes of two mountains, given only the altitudes for the peak and base of mountain A and the base and 1000 feet up on mountain B. You can't calculate anything but average slope of mountain A, and you have no guarantee that the slope so far of B will continue (and you can't look to mountain A for guidance, due to poor resolution).

 

2) Not all extrapolations are equal. If I have two data points, I can draw a line through them. Predicting the point in the middle is a lot more certain than a point far beyond the known range, because even if the trend isn't linear, you're closer to known values. If I know average male human height in the years 1600 and 2000, I'll be more accurate in predicting human height in 1800 than in either 1000 or 3000.

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The fossil record can be used to calculate extinction (and speciation) rates, with appropriate cautions about preservation bias.

 

Preservation bias is one of the things that's being conceptually attacked. It's another extrapolation, so if one were to logically extend the argument, correcting for preservation bias is a guess or speculation. And I'd argue that it isn't.

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The problem with this whole argument is the lack of quantification. We do not know how many species per year went extinct in the Permian event. We do not really know how many go extinct per year today.

 

Prof. E.O. Wilson estimate 30,000 species per year. However, that is based on a calculation with dubious asumptions. For example : a prime assumption is that species loss is mainly due to habitat loss. Hellooooo!!!

 

I know for my own country that about 50 native bird species went extinct in the last 1000 years due to human activity. All died due to over-hunting or the introduction of exotic predators. Not one due to habitat loss.

 

Greenpeace argues 250,000 species per year. Greenpeace is dwelling in Fantasyland.

 

I would rather go by actual data rather than dubious calculations or wild guesses. I have seen various sets of data listing species that have gone extinct, and they range from 2 per year to 20 per year. Assuming the maximum (20), and assuming that only 10% of extinctions are noticed, then we have a total extinction rate of 200 per year. This is certainly wrong, since the data is so poor, but is probably closer than the estimates of thousands.

 

Assuming 200 per year, and assuming 100 million species (not counting prokaryotes), then it will take 450,000 years to achieve the extinction level of the Permian event.

 

This is also certainly wrong. The data is too poor. However, it may help to put things into perspective.

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The problem with this whole argument is the lack of quantification. We do not know how many species per year went extinct in the Permian event. We do not really know how many go extinct per year today

 

Read the links above. While there are problems in resolution for past extinctions, we actually have a very good idea of current rates. Your insistence on 'per year' is splicing the system into irrelevantly small units - per decade or even per century are more than sufficient gradations.

 

Prof. E.O. Wilson estimate 30,000 species per year. However, that is based on a calculation with dubious asumptions. For example : a prime assumption is that species loss is mainly due to habitat loss. Hellooooo!!!

 

Hi. He's right. Remember, speciation often occurs due to geographic separation, and those separations can be small (a river, a ridge of hills, or a tract of different habitat). Many species have highly restricted ranges, and those ranges are being wiped out.

 

I know for my own country that about 50 native bird species went extinct in the last 1000 years due to human activity. All died due to over-hunting or the introduction of exotic predators. Not one due to habitat loss.

 

Irrelevant and a poorly chosen example. Birds have huge ranges, and can often find new habitat with ease.

 

Remember, if we killed every single mammal, bird, reptile, amphibian and fish on the planet tomorrow, that would barely be a blip against the background rate of extinction, since they make up a measly 0.1% of living species. In contrast, there are 250,000 species of flowering plants, which, barring some crappy sci-fi movies, cannot move when the people with chainsaws come.

 

Biodiversity = beetles, snails, and flowers

 

I have seen various sets of data listing species that have gone extinct, and they range from 2 per year to 20 per year. Assuming the maximum (20), and assuming that only 10% of extinctions are noticed, then we have a total extinction rate of 200 per year. This is certainly wrong, since the data is so poor, but is probably closer than the estimates of thousands.

 

You realize that the best estimate of 'background extinction rate' is 1 per year, right? That means by your own numbers, we have a 200-fold increase in extinction.

 

Assuming 200 per year, and assuming 100 million species (not counting prokaryotes), then it will take 450,000 years to achieve the extinction level of the Permian event.

 

1/10th of that many species is a much more widely-accepted number, reducing the duration to 45,000 years. But even 450,000 years is less than half the estimated duration of the Permian extinction. Congrats, you just proved yourself wrong.

 

 

You also make some unfounded assumptions, such as that the Permian 90% figure reflects 90% of all life, not 90% of *fossilized taxa*. You can immediately throw unicellular organisms out, since they don't fossilize at all well, and also throw in a hefty bias towards things that a) are big and b) have hard parts. Vertebrates account for less than 0.1% of all animal life (let alone all organisms), but account for a much greater proportion of fossils, especially on land. Consider that there are currently 15,000 species of annelid worms, but in the fossil record, most will just show up as "worm" or "worm burrow", because the fossils don't preserve enough to allow us to make out species. It's difficult to get fossil arthropods to below family-level classification, if even that, and most never fossilize.

 

Now, consider that big things that fossilize easily are also at greater risk for extinction. Big animals needs more resources, thus more habitat per individual, meaning that a habitat of a given size can support fewer. Small populations are at greater risk of extinction than large ones, so for big animals, the loss of, say, 50% of their habitat is a much bigger problem than for something 1/10th their size.

 

So from the perspective of fossils, you'd see extinctions as being much more severe and rapid than they actually are. If we restricted our current inventory to what some hypothetical future paleontologist would see, the rate would seem much more rapid compared to the known number of species.

 

I would also like to point out that you seem fixated on the End-Permian event and the K-T event. These happen to be two of the three biggest (the second biggest is the Ordovician-Silurian event), but other, smaller mass extinctions have occurred more commonly, resulting in "minor" losses of 20% of species or so.

 

Mokele

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Mokele

I think you are seeing arguments in my last post that are not there. I was not arguing a point - just trying to get a little quantification into the issue of extinction rate, even though I know that any such estimate is almost certainly inaccurate.

 

Any time you try to quantify something so poorly measured, you make assumptions that can be questioned. For example, how many eukaryote species are there? No-one knows. You suggest 10 million. I suggest 100 million based on discussion I have had with various professors of biology. One is a nematologist, and his estimate of the number of marine nematode species is 10 million. There are probably an equivalent number of species of beetle. Suddenly 100 million (an estimate by another prof. I spoke to) seems realistic.

 

I also attended a lecture by a bacteriologist who pioneered whole genome techniques for detecting bacteria in various environments, and his estimate for bacterial species alone is another 150 million, which is why I said 100 million eukaryotes.

 

However, these are only estimates, and one estimate varies from another by a massive amount, so either of us could be correct, or (more likely) both of us are wrong.

 

On extinction by habitat loss - give me ten examples of species that have gone extinct due to habitat loss - when other factors are minimal or non existent. I could readily, from memory give you ten examples of extinctions caused by introduced predators , and another ten due to over hunting by man. Can you do the same for habitat loss?

 

You said :

"Irrelevant and a poorly chosen example. Birds have huge ranges, and can often find new habitat with ease."

 

At least 20 of those species of birds were flightless, and could not do that. They were made extinct by over-hunting, not by habitat loss.

 

Also

"1/10th of that many species is a much more widely-accepted number, reducing the duration to 45,000 years. But even 450,000 years is less than half the estimated duration of the Permian extinction. Congrats, you just proved yourself wrong."

 

I cannot prove myself wrong when I have made no argument. I am happy to accept your view on the rate of Permian extinctions. I just made that point for perspective - not to argue any point.

 

However, I do not think we can equate the current extinction event with that of the Permian (or any other) since it has just begun (10,000 years being an eye blink in biological evolution), and we cannot predict what will happen over the next few thousand years. Hopefully, humans will stop hunting and harvesting to extinction, and will control the spread of alien predators.

 

In the advanced western world, pollution has been substantially reduced, and we are far more environmentally aware than any time in history. This appreciation must spread to third world countries, and control of extinctions globally managed a lot better.

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On extinction by habitat loss - give me ten examples of species that have gone extinct due to habitat loss - when other factors are minimal or non existent. I could readily, from memory give you ten examples of extinctions caused by introduced predators , and another ten due to over hunting by man. Can you do the same for habitat loss?

 

From the IUCN Red List:

 

Atelopus longirostris

Status: Extinct

 

Chrysophyllum januariense

Status: Extinct

 

Cnidoscolus fragrans

Status: Extinct

 

Conuropsis carolinensis (Carolina Parakeet)

Status: Extinct

 

Craugastor chrysozetetes

Status: Extinct

 

Cryosophila williamsii (Root-spine Palm)

Status: Extinct in the Wild

 

Discoglossus nigriventer (Hula Painted Frog)

Status: Extinct

 

Elaphurus davidianus (Père David's Deer)

Status: Extinct in the Wild

Pop. trend: increasing

 

Ilex gardneriana

Status: Extinct

 

Juscelinomys candango (Candango Mouse)

Status: Extinct

 

Madhuca insignis

Status: Extinct

 

Myrcia skeldingii

Status: Extinct

 

Philautus travancoricus

Status: Extinct

 

Pouteria stenophylla

Status: Extinct

 

Pradosia glaziovii

Status: Extinct

 

Rheobatrachus silus (Southern Gastric Brooding Frog)

Status: Extinct

 

Rheobatrachus vitellinus (Northern Gastric Brooding Frog)

Status: Extinct

 

Sterculia khasiana

Status: Extinct

 

Taudactylus diurnus (Mount Glorious Torrent Frog)

Status: Extinct

 

Traversia lyalli (Stephens Island Wren)

Status: Extinct

 

Vanvoorstia bennettiana (Bennett's Seaweed)

Status: Extinct

 

Wendlandia angustifolia

Status: Extinct

 

Note: this is just a list of species (22 of them) that went extinct due to residental and commercial development. If I add in other factors that destroy habitat, such as climate change, pollution, mining, and habitat fragmentation, the total jumps to 137.

 

The species killed by invasive species or hunting get all the press because it's 'sexier' than "and then we built a car park over the last breeding pond, and they all died."

 

At least 20 of those species of birds were flightless, and could not do that. They were made extinct by over-hunting, not by habitat loss.

 

You completely missed the point. Bird species losses are not going to be subject to the same factors are losses in beetles, worms, fish, and a thousand other species that are much more representative of earth's biodiversity. I'm not disputing the causes of those, I'm saying they're a poor example to generalize from.

 

However, I do not think we can equate the current extinction event with that of the Permian (or any other) since it has just begun (10,000 years being an eye blink in biological evolution), and we cannot predict what will happen over the next few thousand years. Hopefully, humans will stop hunting and harvesting to extinction, and will control the spread of alien predators.

 

I agree, and said so in my initial response to the OP.

 

However, what we have already done is enough to qualify as a minor mass extinction, especially when you consider all the Pleistocene megafauna we've killed.

 

It's also worth noting that just because something isn't dead yet, doesn't mean it will survive. Some endangered species have such low populations that nothing can save them - inbreeding depression will finish what we started. Hell, look at Lonesome George, a single Galapagos tortoise who represents the last of his species. Granted he'll probably live another 70 years, but when he dies, that's it.

 

Mokele

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On Atolepus longirostris, Wiki says :

"The species has been classified as extinct, due to huge declines probably related to chytridiomycosis, climate change, among other synergistic causes."

Main cause of extinction - an introduced pathogen - the chytrid fungus.

 

Chrysophyllum januariense is a tree once found in the Laranjeiras Forest, which is a protected habitat and still clearly there. Since the forest has not gone, it is a bit disingenuous to claim this species died out due to habitat loss.

 

Cnidoscolus fragrans. I could not find a resource that described the cause of this extinction.

 

Conuropsis carolinensis, the carolina parakeet according to Wiki died out because (I quote):

"The Carolina Parakeet died out because of a number of different threats. To make space for more agricultural land, large areas of forest were cut down, taking away its habitat. The colorful feathers (green body, yellow head, and red around the bill) were in demand as decorations in ladies' hats, and the birds were kept as pets. Even though the birds bred easily in captivity, little was done by owners to increase the population of tamed birds. Finally, they were killed in large numbers because farmers considered them a pest, although many farmers valued them for controlling invasive cockleburs. It has also been hypothesized that the introduced honeybee helped contribute to its extinction by taking a good number of the bird's nesting sites.[3]"

 

I could go on, but running down this kind of data is very time consuming. The point is that clear cut cases of extinctions due to habitat loss are very rare. Normally habitat loss is listed as just one of a series of causes, and it is debatable how important a cause it might be.

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The links I provided gave numbers of measured events. Evidence.

Considering that the second one is a Science Daily article about an apparent oped column in American Scientist, would you care to reconsider that?

 

I also find this a little interesting;

Some 2,000 species of Pacific Island birds (about 15 percent of the world total) have gone extinct since human colonization. Roughly 20 of the 297 known mussel and clam species and 40 of about 950 fishes have perished in North America in the last century.

 

For the first part, how long have the islands been colonised? Tonga and Samoa were colonised some 3,000 years ago. For the birds to become extinct, they were almost certainly non-migratory and confined to a single island or small group of islands. (Which means that a good cyclone or tsunami could cause their extinction as well) Anyway, saying "2,000 species of localised bird populations have disappeared in the Pacific over the last 3,000 years" is a more accurate statement, but it just doesn't have the same apocalyptic ring, does it?

 

For the second part. Just because an animal has "vanished" from America doesn't mean it's extinct, just that it's no longer found in North America. 20 out of 297 mussel species sounds impressive (it's nearly 10%!), but is it? Redlist says there are an estimated 81,000 species of molluscs, so 20 of them "vanishing" from North America is far less than a drop in a bucket. 40 of 950 fish is circa 4%, yet the same Redlist table shows that worldwide only 4% are threatened, not extinct, not vulnerable, but threatened.

 

Swansont, just to be clear. Yes, it is obvious that the spread of man has led to extictions, I can't see how there can be any argument about that. Some of those extinctions were unintentional (we didn't care), some were accidental (we didn't intend to hunt them to extinction) and some were deliberate (islands can be a bit small for both humans and tigers).

 

However I've yet to see anything that provides a factual basis for the doom and gloom predictions.

 

We can all play with numbers. I could claim (and use Redlist to back me up) that "56% of evaluated species of Arachnids are threatened!" I mean, My God, that's horrific. Until that is, someone actually looks at the figures and sees that of an estimated 98,000 species of Arachnid, only 32 have been "evaluated". Those 18 threatened species are suddenly an insignificant minority.

 

As an aside, I think their coral figures are odd. Not saying they're wrong, but I'd love to know how the number of threatened species goes from 1 in 2006 to 4 in 2007, to a whopping 235 in 2008. Just seems odd.

 

Mokele, thanks for the links. I've give them a read.

especially when you consider all the Pleistocene megafauna we've killed.

Is this confirmed? I knew that overhunting was "a" theory for the megafauna extinctions, but I didn't know that we had evidence. I must admit, I've always had trouble with the idea that the Australian Aboriginal, armed wih a fire hardened stick, hunted the Megalania to extinction.

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I could go on, but running down this kind of data is very time consuming. The point is that clear cut cases of extinctions due to habitat loss are very rare. Normally habitat loss is listed as just one of a series of causes, and it is debatable how important a cause it might be.

Let's not go through all this again.

The degree to which the ever-nebulous "habitat loss" causes extinction is tangential to the topic.

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