Guest post by Dr. Craig Loehle
Last year, Willis Eschenbach had a WUWT post about extinction rates being exaggerated in the literature. I offered to help him get this published, and it is now out. We conclude that the extinction crisis for birds and mammals is very specific to island fauna which are uniquely sensitive to human impacts, including our pets and commensals like rats. It is not valid to extrapolate these extinctions to either the problem of deforestation on continents or to future impacts of climate change.
The process of getting this published was relatively painless which is surprising given how much we counter conventional wisdom in it. The paper is available free at Researchgate.
I would argue that blogs CAN be a real part of the scientific process. I would recommend that people follow up on good ideas they see and get them into print as this example illustrates.
Loehle, C. and W. Eschenbach. 2011. Historical Continental Bird and Mammal Extinction Rates. Diversity & Distributions DOI: 10.1111/j.1472-4642.2011.00856.x
Methods: We examined historical extinction rates for birds and mammals and contrasted island and continental extinctions. Australia was included as an island due to its isolation.
Results: Only six continental birds and three continental mammals were recorded in standard databases as going extinct since 1500 compared to 123 bird species and 58 mammal species on islands. Of the extinctions, 95% were on islands. On a per unit area basis, the extinction rate on islands was 177 times higher for mammals and 187 times higher for birds than on continents. The continental mammal extinction rate was between 0.89 and 7.4 times the background rate, whereas the island mammal extinction rate was between 82 and 702 times background. The continental bird extinction rate was between 0.69 and 5.9 times the background rate, whereas for islands it was between 98 and 844 times the background rate. Undocumented prehistoric extinctions, particularly on islands, amplify these trends. Island extinction rates are much higher than continental rates largely due to introductions of alien predators (including man) and diseases.
Main Conclusions: Our analysis suggests that conservation strategies for birds and mammals on continents should not be based on island extinction rates, and that on islands the key factor to enhance conservation is to alleviate pressures from uncontrolled hunting and predation.
Table 1: Extinctions since 1500 according to IUCN and CREO, with per species and per unit area rates.
Abstract:
Loehle, Craig, and Willis Eschenbach. 2011. Historical bird and terrestrial mammal extinction rates and causes.
Diversity and Distributions. doi: 10.1111/j.1472-4642.2011.00856.x
We examined historical extinction rates for birds and mammals and contrasted island and continental extinctions. Australia was included as an island because of its isolation. Only six continental birds and three continental mammals were recorded in standard databases as going extinct since 1500 compared to 123 bird species and 58 mammal species on islands. Of the extinctions, 95% were on islands. On a per unit area basis, the extinction rate on islands was 177 times higher for mammals and 187 times higher for birds than on continents. The continental mammal extinction rate was between 0.89 and 7.4 times the background rate, whereas the island mammal extinction rate was between 82 and 702 times background. The continental bird extinction rate was between 0.69 and 5.9 times the background rate, whereas for islands it was between 98 and 844 times the background rate. Undocumented prehistoric extinctions, particularly on islands, amplify these trends. Island extinction rates are much higher than continental rates largely because of introductions of alien predators (including man) and diseases. Our analysis suggests that conservation strategies for birds and mammals on continents should not be based on island extinction rates and that on islands the key factor to enhance conservation is to alleviate pressures from uncontrolled hunting and predation.
Copyright © 2011 by Blackwell Publishing Ltd. All rights reserved. Article posted on this website with permission.
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(Adobe PDF) Loehle & Eschenbach2011
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Willis Eschenbach is a retired polymath
what is a polymath?
vicepapr says:
October 26, 2011 at 11:18 am
My dictionary says
But I hit the age ceiling, so I retired.
w.
PS—Actually, that’s a slight exaggeration. Before I hit the age ceiling, I could no longer pass the physical … but don’t mention that to the babes, vicepapr, keep that part between us, OK? …
Congratulations! Publications always feel good, and I hope that you feel good about this one. Keep up the good work.
Ged, this is a rather complex area and I am trying to be analytically critical, not being critical for its own sake.
I acknowledged that I had not caught the typo in Table 1 where the mislabeling of the Passenger Pigeon.
I dispute that the Great Auk is not included as a trans-continental species, but as an Island species.
I do not accept you facile definition of species; for instance my own species, Homo sapiens, successfully mated with Homo neanderthalensis and I carry about 7% neanderthalensis.
The Common Chimpanzee, Pan troglodytes and the Bonobo, Pan paniscus have also been successfully mated.
Durum wheat is a species that resulted from the hybridization of two different diploid grass species, Triticum urartu and Aegilops speltoides.
Speciation events are more likely to occur in islands, compared to continents. The depth of the genetic pool, the sum of the genetic diversity within a species, will be very much lower in island species than compared with MOST continental species; but not always.
The cheetah, Acinonyx jubatus is a large continental animal, and is also a specialist.
It fills a very narrow niche. The cheetah almost went extinct in the very recent past, we know that this species was subject to a very tight evolutionary bottle-neck 10,000 years ago, barely avoiding extinction at the end of the last ice age.
Top predators are in terms of niche size, island species, regardless of their physical range. Though you may not believe it, the extinction rate of top specialized predators is very high.
One should note that for grass eating herbivores selection pressure selects large animals, the large they get the more efficient they are at extracting energy from their food, the more successful the males are in fighting for females and the less predation they suffer.
Thus, over evolutionary time the size of herbivores increases. This leads to an arms race with predators. To be able to predate the large herbivores the predators need to get larger and become more specialized.
The animal we think of as a saber-toothed tiger is really a large number of sub-species of the machairodontine, when through various cycles of specialization from a generalist medium sized big cat into top large mammal predator to extinction. The cycle of size/sepcialization followed the size of the herbivore, and this followed the ecology, which was triggered by the climate.
http://www.behav.org/student_essay/evol/dorgai_Smilodon.pdf
I MY opinion, analyzing the rate of extinction in terms of depth of genetic pool, physical and nutrient niche size would be much better than classifying animals as either Island/Continent species. I say this because whilst these terms may mean something, in some cases, in other they do not. For instance, Proteus anguinus is a cave salamander found in Europe. These occupy a very small island niche, even though they are a continental species. The same goes for the Texas Blind Salamander,Eurycea rathbuni) which is a rare cave-dwelling amphibian native found only in the San Marcos Pool of the Edwards Aquifer.
“Ged says:
Are you proposing the ratio between island and continent would significantly change under new criteria away from the results of this paper? Show us the evidence by doing the analysis if you believe so.”
If the Great Auk were included then the number of continental species would change by 7/6, so the ratios would be modified somewhat.
The use of a ‘soft’ group of species, like the great Auk which do not fall conveniently into either island/continental classification would allow one to use a statistical estimate.
I did not want to rain on anyone’s parade, nor do I wish to attack either Craig or Willis.
However, I think their classification is too simplistic and lacks the input from an evolutionary biologist/ecologist.
Some nodding aquatance with Hutchinson’s hypervolumic niche description would have greatly helped this paper. With luck this publication will lead an ecologist to build on this work by Craig or Willis.
My criticisms are in no way personal, but if we are going to dissect papers we have a fundamental disagreement with, shouldn’t we do the same to other ones we find general merit with?
DocMartyn: I AM an ecologist. Defining terrestrial “islands” like caves is much more subjective than physical islands, and these islands are only isolated genetically, not from predators or competitors (with very few exceptions). We do not claim to have exhausted the subject–lots more still to do. 6/123 does not differ appreciably from 7/123.
Congratulations Willis and Dr. Loehle, It is nice to see real science done with out the alarmism.
“Craig Loehle
DocMartyn: I AM an ecologist. ”
Sorry for the unintended slight.
DocMartyn, the Red List says of the Great Auk:
In other words, it is basically an island species. And this, of course, is the reason it went extinct. Humans went to those remote islands that had no natural predators, and predated the Auk into oblivion. So it was an island living species.
More to the point, however, it was an island breeding species. As this is the time when birds are most vulnerable to extirpation, we listed birds that bred on islands with the island species. That information was included in early versions of the paper, although it seems to have been lost in one of the many rewrites. However, we list that among the reasons for considering islands separate from continents:
In the same way, bird species that bred on the continents were counted as continental species, despite the fact that they might spend some part of their lives on islands.
And the Great Auk, because it “ground-nested … on predator-free islands”, was included with the island birds.
HTH,
w.
Craig Loehle & Willis Eschenbach,
Congratuations on your good work and achieving publication in a journal.
I look forward to reading your published paper this weekend.
Craig wrote:
Defining terrestrial “islands” like caves is much more subjective than physical islands, and these islands are only isolated genetically, not from predators or competitors (with very few exceptions).
The problem here, as DocMartyn has so patiently pointed out, is that vulnerable continental species almost uniformly inhabit “island” habitats. The nine continental extinctions listed in Table 1 include at least five species that inhabited very discrete islands of suitable habitat. Craig’s statement gets dangerously close to circular reasoning (partly because the concept of “habitat” is dangerously close to circular). Because of the prevalence of “island” extinctions on continents, what the paper actually shows is that island/continental is a false dichotomy. This terrain has all been covered in the literature on serpentine specialization, with most of the important work being done in Willis’ home state of California.
Matt Skaggs says:
October 27, 2011 at 7:26 am
As Craig pointed out, it’s easy to tell Hawaii from Nebraska. Why? It’s an island.
And although DocMartyn doesn’t see it, it seems to make a fundamental difference in the extinctions of birds and mammals. Birds and mammals on islands, where there is little exchange with the outside world, are extremely vulnerable to introduced species. These introduced species have caused ~95% of the world’s extinctions.
Now, it is tempting to call some restricted range for some continental species an “island”. You say:
But that’s just a misuse of language. All you mean is that they have geographically defined ranges. But that’s not what makes an island species vulnerable. For the current purposes, the thing that makes a real island different from an “island” on the continent is that (except humans) predator don’t have boats. So those islands (the real ones) were free of certain predators for millions of years.
But predators, from shrews to tigers, happily cross and recross the borders of what you wrongly name “islands” of defined geographical ranges on the continent. There’s nothing stopping them.
It is that exclusion of predators, for millions of years, that has made the island species vulnerable. And no matter if you call a continental animal’s range an “island”, with very few exceptions it doesn’t have that complete isolation from predators that we find in actual islands.
So when you say:
I can only answer that we didn’t discuss “island” habitats, we discussed island habitats. It’s like the old joke. How many legs does a cow have, if you call a tail a leg?
…
Four. Calling a tail a leg doesn’t make it a leg. And in the same way, no matter how patient DocMartyn might be, calling a chunk of a continent an island doesn’t make it an island.
w.
Here’s what the late John McCarthy, father of Artificial Intelligence and inventor of Lisp, has to say.
http://www-formal.stanford.edu/jmc/progress/biodiversity.html
We’ve just lost a genius.(No, I’m not saying that because he essentially agrees with Willis.)
Willis,
Reading from your paper, the Atitlan grebe went extinct because of the introduction of the exotic largemouth bass into the one lake that comprised its entire habitat. As far as the grebe was concerned, that lake surrounded by land was exactly analogous to an island habitat. In your paper, you called that tail a leg when you lumped it with the passenger pigeon and not the dodo. That is why your paper will draw a yawn from the folks actually trying to understand this stuff.
“although DocMartyn doesn’t see it, it seems to make a fundamental difference in the extinctions of birds and mammals. Birds and mammals on islands, where there is little exchange with the outside world, are extremely vulnerable to introduced species. These introduced species have caused ~95% of the world’s extinctions”
Whereas the Great Auk was widespread going from New England, Eastern Canada, Greenland, Iceland, Great Britain and Ireland and the Scandinavian nations. We know that more than 100,000 years ago Neanderthals hunted Great Auks as their bones/egg shells have been found at Neanderthal sites.
The Great Auks were killed off very slowly, by Polar Bears and by Humans. Their eggs and down was so valued by humans that they ended up with only a few Island refuge’s. They were hunted by native North Americans, the colonists, the Inuit,
“All you mean is that they have geographically defined ranges. But that’s not what makes an island species vulnerable”
What makes a species vulnerable? 1) highly restricted location (Island, lake or cave species), 2) shallow genetic pool (Island, lake and cave species), 3) High specialization (not unique to continent or island), 4) Immunological/defensively naivety toward predation (continent or island) and 5) Genetic diversity/population size.
4) is a big one. Dutch Elm disease, loss of the American Chestnut, loss of the European wine-vine, loss of many potato species, loss of much of the Native American population. Introduction of rats into island does wipe out ground nesting birds. However, introducing large fish into lakes can also wipe out birds.
5) the background level of a neutral genetic polymorphism in a population is about 6%. The larger number of individuals you have the wider and deeper the genetic pool. Genetic diversity is the currency of speciation/survival. Richard Lenski’s demonstration of the evolution of a E. Coli citrate utilizing strain was probably the best best example of this.
http://en.wikipedia.org/wiki/E._coli_long-term_evolution_experiment
Some time around generation 20,000 there was established a genetically neutral change in one of his populations that predisposed them to being able to utilize citarte, at some future data; around generations 31,000 and 31,500.
The bigger you population, the wider and deeper your genetic pool and the higher the species elasticity.
The species specific size of an ELE will, amongst other things, depend on the ‘range’ of the species, not necessarily where the range is. A cave system, an isolated lake, the Paris underground system represent ‘Islands’; but the nesting of the Great Auk on island does not make them an Island species.
This is why I disagree with your exact methodology.
DocMartyn: it is not that the Great Auk was isolated genetically but that it had the habit of nesting on islands without predators, so it was vulnerable to predation (specifically humans). If small population size and/or restricted habitat was sufficient to cause extinction there would surely be more extinctions on continents since many birds and mammals have small populations and/or restricted ranges. Also, to try to a priori categorize continental species as “island” species using this method of identification is very subjective. Many authors and the Endangered Species Act in USA essentially identify all rare species as endangered, but forecasts based on this assumption are not coming true yet.
And yes, of course introducing diseases and pests like dutch elm disease is a really bad idea, but island species are probably even more susceptible.
Matt Skaggs says:
October 27, 2011 at 11:31 am
OK, throw out the Atitlan grebe entirely, and class it with the dodo. I actually had considered doing that, since it lived on an island in the lake. I eventually decided to leave it in so people wouldn’t complain I was incorrectly lowering the number of continental extinctions … but of course, I hadn’t reckoned with your amazing ability to snatch triviality from the jaws of knowledge …
It doesn’t change one jot or tittle of our conclusions if we class the grebe with the island species. In fact, it makes our argument stronger, it means less continental extinctions. In other words, you are insulting me and wasting perfectly good electrons over a meaningless point that is actually in favor of our arguments.
Color me unimpressed with your claims and your attitude. If what you were on about were anything important you might be justified in your passion.
But getting all snarky over the grebe, which makes no difference to the conclusions of the paper? OK, remove the grebe entirely, it makes no difference, in fact it improves our argument to leave it out. That’s why I left it in, to be scrupulously fair. But heck … take it out. I’m reminded by your attitude of why university politics is so nasty.*
w.
PS—I love the part where you are concerned by the methods/conclustions of the paper, and you tell us that DocMartyn has been patient in re-explaining what his point is about the paper, and you think it’s an issue that is important enough to discuss at length and to passionately restate your point several times … and then you claim that the paper will just “draw a yawn from the folks actually trying to understand this stuff …
These two facts you have presented leave us, as far as I can see, with only two possible conclusions:
1) You are wrong about the paper just drawing a yawn, or
2) You are not “actually trying to understand this stuff”
I’m voting for 1) myself, but it’s your choice, report back.
* Because there’s so little at stake.
People wonder how long it takes to get an idea into print. The first draft of this paper was written in 2002.
In The Diversity Of Life (Wilson 1992), E. O. Wilson postulated that we are in the midst of the sixth great wave of extinctions. He based this claim on the “species/area relationship”, which was said to mathematically relate the size of an area to the number of species it could hold. The claim was that reducing the area would drive a large number of species extinct.
This claim has been picked up and repeated in many scientific and popular papers. The source of these extinctions is said by Wilson to be the reduction of forest habitat, both tropical and temperate. In 1992 claimed that at that point, some 27,000 species were already going extinct every year from forest habitat reduction.
Being the untrusting fellow that I am, not long after reading that I decided to research it. I didn’t think that life was that mathematically simple, and the parts I’d been in contact with had been uniformly hard to kill.
So I got the Red List and the CREO list of extinctions. Because birds and mammals are the most visible and most studied forms of life, and because Wilson himself said (and reasonably so) that larger creatures were more likely to go extinct, I decided to study those two kinds of beings. Birds and mammals.
The problem is the numbers are nowhere near to adding up. We know the approximate numbers of bird and mammal species, and we know the number of total species that Wilson used for his estimates. So we know what percentage of the putative 27,000 extinctions per year should be birds and mammals. Wilson’s figures clearly say we should have already seen hundreds of extinctions of both birds and mammals, even accounting for a long lag in the extinctions. Naive fellow that I was then, I set out to look for Wilson’s claimed extinctions, those animals gone extinct from reduction of their forest habitat.
Since I had the inestimable advantage of knowing nothing about the field, I started by looking at all of the extinctions. I soon realized that a tiny area of the world (those areas not visited by outsiders in hundreds of thousands of years) held almost every one of the extinctions. They all occurred either on islands or on Australia, and in almost every case for a simple reason—introduced species. Humans, of course, but also foxes, rabbits, rats, dogs, a huge spectrum of diseases, and the under-appreciated bird-and-beast killing and definitely not extinct House Lion, felix domesticus.
But despite humans cutting forests for hundreds of years, I couldn’t find any extinctions from forest habitat reduction.
What was even more surprising to me (being unacquainted with the numbers) was that in all of Asia, and Africa, and Europe, and North America, and South America, there were only 9 extinct species in 500 years. I would have guessed many, many more than that on the continental land masses. Only nine.
I found that astonishing. So I wrote it all up. I submitted it to some journal. They kicked it back with comments from the reviewers that totally discouraged me. Knowing what I know today I might have forged ahead, but then, the theme was “you’re an amateur, leave it to the professionals, we know that the species/area relationship to predict extinctions is correct.” It was also written as I write, not in dense, compressed blocks of text like the journals want. I tried to crunch it together like that, but you could see the seams …
Since my paper showed that the species/area relationship is not correct, even if I re-wrote it, I could read the writing on the wall. I circulated it privately, and put it with my other studies to let it mellow like good wine.
Some seven years later I resurrected it and made it into a blog post. Craig Loehl agreed with the analysis and offered to work with me to turn it into a journal paper. I gratefully accepted (and have other papers and blog posts worthy of journal articles, if anyone else wants to offer to do a huge pile of work like Craig did, you get to be lead author.)
Now, remember my intention was to overthrow the use of the species/area relationship to predict extinctions. It doesn’t work. In my opinion, this is because life is sneaky and underhanded and incredibly tenacious and will sneak through hidden gaps and grow up through the concrete if it has to.
I consider the publication of this paper to be a signal achievement, particularly for an amateur scientist like myself. At a stroke I have shown that a long-held mathematical relationship, the “species/area relationship” used to predict extinctions, is incorrect and is contradicted by observations.
I have also shown that the modern continental extinction rates are not significantly different from historical extinction rates. This means that the oft repeated claim that we are in a “sixth wave of extinction” has no scientific foundation. The “sixth wave of extinction” claim was fabricated entirely and completely on the “species/area relationship”, and it is thus also overthrown.
Not bad for a reformed cowboy off a cattle ranch, I’d say, but my bias is obvious …
w.
Willis,
Calm down. Your main conclusion was “conservation strategies for birds and mammals on continents should not be based on island extinction rates and that on islands the key factor to enhance conservation is to alleviate pressures from uncontrolled hunting and predation.” My point is that at least five of the nine continental extinctions were functionally island extinctions, and that conflicts with your conclusion. If you want to understand the extinction of the slender-billed grackle, the Omilteme cottontail rabbit, or the Atitlan grebe, you want to approach these extinctions as island-type events (staying away from extra quotation marks here).
DocMartyn says:
October 27, 2011 at 1:10 pm
You are 100% correct, Doc … but it does make them vulnerable to introduced species on those islands.
And that is why we classed birds by where they breed, not by where they lived. Actually, there’s another reason, is that it is a “bright line” distinction. A bird may live over its lifetime in many habitats. But typically, they breed in only one kind of habitat.
This gave us a clear method of distinguishing between “island” birds and “continental” birds, by dividing them based on nesting location. So it was a clear distinction as well as a useful one, putting the those birds at risk of extinction from introduced species on their island breeding sites in with the “island” group. And that is why the Auk is classed with the “island” rather than the “continental” group.
Here’s the point. Whether or not the Auk should be counted “continental” or “island”, it is not one of E. O. Wilson’s claimed extinctions from habitat reduction. It was driven extinct by predation.
So whichever way you class it doesn’t matter. It doesn’t even change the continental bird extinction rate appreciably, it increases by one part in six. But that leaves it still well within the uncertainty of the historical rates of extinction.
Now Doc, if you want to divide birds on some basis other than where they nest, be my guest. You could divide them based on where they eat, or where they congregate, or where they fly over. The division we used is both clear and useful, in that it puts birds at risk from introduced species all in one group. But if you want to class them based on where you find them in June, go for it.
My point is that we used ex ante, clear criteria for dividing them into “island” and “continental” groups, based on where they nest. Those criteria revealed interesting things. Claiming we should have used other criteria? Sure, we could have done a host of things differently … but then we wouldn’t have found out what we did.
w.
Willis, you are not taking it this well. I think you and Craig are essentially correct, but I think your classification leaves much to be desired.
I have not being attacking you, Craig nor your approach or goal.
What I actually think you are describing is the propensity of species to develop a ‘glass-jaw’.
Normally, the majority of selection pressure is within a species, not without. Almost every aspect of a species morphology, behavior and biochemistry represents a metabolic/temporal opportunity cost. Cave species show that the removal of a selective advantage from a niche rapidly leads to genetic/phenotypic atrophy; cave species lose eyes, pigmentation and the repair mechanisms for repairing uv induced DNA damage.
Humans, and other great apes, are the result male sexual selection.
Monkeys gain an enormous advantage in their ability to climb trees, they are able to evade predators and access food sources unavailable on the ground.
The cost is big brains, long tails and forward facing eyes.
Monkeys also have a problem with sex. There is male competition for females, and the largest males tend to have more progeny. In the long run, males become larger and larger. The tail can no longer support the Super-Sized Monkey and becomes a bit of a pin in a Male-Male fight, so that goes. After a while the males are so big they can hardly (Chimps/Bonobos) or simply can’t climb trees (Humans, Gorillas and Orang’s). Luckily, the arboreal small to medium size transition seems to have allowed the apes to leap the majority of predators, and in our case the big brains came in very useful.
Male African elephants use their tusks in fighting other males, they are a product of sexual selection.African elephant populations have been very damaged by Ivory hunters, some 13% of males now do not have Tusks. Having tusks is the largest negative selection pressure on the elephant and the length of tusks in the tusk has collapsed over the last 150 years. The elephants are losing their ‘glass-jaw’. They could, because they had a very large number of starting numbers, a deep/wide genetic pool and can physically move about.
Island species typically lose a major predator or many major predators, so there is often a switch from tree to ground nesting and a major down regulation in their immune systems. One would expect that intraspecies selection pressure would be much greater than in larger niches, especially sexual selection.
These species become fitted to their, very small, niche and so a change in their niche can be devastating.
I absolutely agree that a small rise in temperature is completely different from suddenly be presented with a new super predator. I also think it reasonable to attempt to try to estimate how different these selection pressures are. However, I think you classification system if not as useful as it could be.
I actually think the best way to do this would be experimentally.
Myself, I would grow bacteria, take 10 single founder E. Coli cultures and 10 genetically diverse E. Coli cultures. Grow them on a really, really rich medium for a year, under the same every other day splitting routine.
After a year test their sensitivity to a range of diverse stressors; pH, heat, Paraquat, osmotic stress, salinity, e.t.c.
At worst, this will give you an idea of the loss of elasticity one gets from a founder effect.
Finally got ‘er read. Extremely interesting stuff, Craig and Willis.
DocMartyn says:
October 27, 2011 at 4:07 pm (Edit)
Thanks for that, Doc. I’m still not clear what your point is. For a while it was Great Auks. Now it’s genetically diverse E. Coli cultures.
What’s not clear is what that has to do with what we have shown. For all the faults you perceive in our method, we have demonstrated and provided evidence that:
1) The species/area relationship doesn’t work to predict extinctions, and
2) The claims of a “sixth wave of extinction”, which are based on the species/area relationship, are false.
3) The extinction rates on the continents are not statistically different from the historical rates.
I don’t have a clue how the evolution of blind cave animals or of E. Coli has anything to do with those three things. We presented a paper on the historical extinction record. It demonstrated some pretty amazing things.
Now you tell us that we should have studied E. Coli and we didn’t include the “glass-jaw” and we failed to consider that in elephants “the length of tusks in the tusk has collapsed over the last 150 years” … say what???
Sorry, Doc, I’m not following you at all. How would any of that have improved or even changed what we set out to show? Our paper has provided extensive evidence overturning two decades of “species/area” extinction nonsense, what more do you want?
w.
O.K. Willis. I give up. You win. Trying to understand species robustness and sensitivity to extinction stressors is obviously not at all of interest.
DocMartyn says:
October 27, 2011 at 5:17 pm
Not true. I am interested. I’m interested enough in the subject to research and write a paper about it. It’s something I care about. I’ve discussed speciation with experts, I’m curious about it.
Which is why I took the trouble to read and re-read what you wrote. But I couldn’t understand it. I’m sorry, but it wasn’t at all clear what your point was. I mean the words were clear, but I didn’t understand what it had to do with my paper on bird and mammal extinctions.
So I wrote to say I wasn’t following you. I asked how what you were explaining would have changed or improved our paper.
Let me pause here and look at the situation. You can respond to that in a variety of ways. You can answer my questions. Or restate your three main points in three sentences. Or ask me questions to find out where from your perspective I’m going off the rails. Or explain what you think I misunderstand.
There’s lots of things you can say in response to my post. However, you can’t accuse me of not being interested, Doc. That’s simply not true.
w.