Guest post by David Middleton
Sixth Mass Extinction or Sixth Mass Genesis?
Animals and plants are seemingly disappearing faster than at any time since the dinosaurs died out, 66m years ago. The death knell tolls for life on Earth. Rhinos will soon be gone unless we defend them, Mexico’s final few Vaquita porpoises are drowning in fishing nets, and in America, Franklin trees survive only in parks and gardens.
Yet the survivors are taking advantage of new opportunities created by humans. Many are spreading into new parts of the world, adapting to new conditions, and even evolving into new species. In some respects, diversity is actually increasing in the human epoch, the Anthropocene. It is these biological gains that I contemplate in a new book, Inheritors of the Earth: How Nature is Thriving in and Age of Extinction, in which I argue that it is no longer credible for us to take a loss-only view of the world’s biodiversity.
[…]
Climate change has brought tree bumblebees from continental Europe to my Yorkshire garden in recent years. They are joined by an influx of world travellers, moved by humans as ornamental garden plants, pets, crops, and livestock, or simply by accident, before they escaped into the wild. Neither the hares nor the rabbits in my field are “native” to Britain.
Many conservationists and “invasive species biologists” wring their hands at this cavalcade of “aliens”. But it is how the biological world works. Throughout the history of the Earth, species have survived by moving to new locations that permit them to flourish – today, escaped yellow-crested cockatoos are thriving in Hong Kong, while continuing to decline in their Indonesian homeland.
Nonetheless, the rate at which we are transporting species is unprecedented, converting previously separate continents and islands into one biological supercontinent. In effect, we are creating New Pangea, the greatest ecological pile-up in the Earth’s long history. A few of the imported species cause others to become extinct – rats have driven some predator-naïve island birds to extinction, for example. Ground-nesting, flightless pigeons and rails that did not recognise the danger were no match for a deadly combination of rodents and human hunters.
But despite being high-profile, these cases are fairly rare. In general, most of the newcomers fit in, with limited impacts on other species. The net result is that many more species are arriving than are dying out – in Britain alone, nearly 2,000 extra species have established populations in the past couple of thousand years.
[…]
There is no doubt that the rate at which species are dying out is very high, and we could well be in for a “Big Sixth” mass extinction. This represents a loss of biological diversity. Yet, we also know that the Big Five mass extinctions of the past half billion years ultimately led to increases in diversity. Could this happen again? It seems so, because the current rate at which new animals and plants (such as the apple fly, the Italian sparrow and Oxford ragwort) are coming into existence is unusually high – and it may be the highest ever. We are already on the verge of Genesis Number Six – a million or so years from now, the world could end up supporting more species, not fewer, as a consequence of the evolution of Homo sapiens.
[…]
Chris D Thomas, Professor of Evolutionary Biology, University of York
This article was originally published on The Conversation. Read the original article.
For starters, the use of the phrase Anthropocene is, at best, silly. The Holocene *is* the Anthropocene. And, the description of the current species extinction rate as a “mass extinction” is totally wrong. Mass extinctions are marked by the loss of not just species; but by entire genera, families, orders, classes and sub-phyla.
The Late Pleistocene to Early Holocene extinction is not classified as a mass extinction, despite the loss of many genera.
It’s been quite a while since a genus was declared extinct, and it might actually be extant… just hiding…
Entire Mammal Genus on Brink of Extinction
Critically endangered African antelope is last species of its kind.
By Christine Dell’Amore, National Geographic News
PUBLISHED NOVEMBER 8, 2011
For the first time in 75 years, an entire genus of mammal may go the way of the dodo—unless a new conservation effort shepherded by Somalian herders succeeds.
The hirola, a large African antelope known for its striking, goggle-like eye markings, is the only remaining species in the genus Beatragus—and its numbers are dwindling fast, conservationists say.
The last mammal genus to blink out was Thylacinus, in 1936, with the death of the last Tasmanian tiger. A genus is a taxonomic ranking between species and family.
[…]
There are 30 genera of antelope and that doesn’t count American antelope, which technically aren’t antelope… So the demise of the hirola won’t be the death knell for antelope.
Reports of the Tasmanian tiger’s extinction might be just a bit premature.
The current mass extinction isn’t exactly taking a huge toll on any taxonomic units above the species level.
So, this image is totally meaningless for at least three reasons:
- It’s denominated in species.
- It fails to address the rate of new species evolving and/or being discovered.
- It would not be resolved in the fossil record – as the five real mass extinctions are.
Earth Is Not in the Midst of a Sixth Mass Extinction
“As scientists we have a responsibility to be accurate about such comparisons.”
PETER BRANNEN JUN 13, 2017
At the annual meeting of the Geological Society of America, Smithsonian paleontologist Doug Erwin took the podium to address a ballroom full of geologists on the dynamics of mass extinctions and power grid failures—which, he claimed, unfold in the same way.
[…]
I had written to Erwin to get his take on the contemporary idea that there is currently a sixth mass extinction under way on our planet on par with the so-called Big Five mass extinctions in the history of animal life. Many popular science articles take this as a given, and indeed, there’s something emotionally satisfying about the idea that humans’ hubris and shortsightedness are so profound that we’re bringing down the whole planet with us.
[…]
Erwin says no. He thinks it’s junk science.
“Many of those making facile comparisons between the current situation and past mass extinctions don’t have a clue about the difference in the nature of the data, much less how truly awful the mass extinctions recorded in the marine fossil record actually were,” he wrote me in an email. “It is absolutely critical to recognize that I am NOT claiming that humans haven’t done great damage to marine and terrestrial [ecosystems], nor that many extinctions have not occurred and more will certainly occur in the near future. But I do think that as scientists we have a responsibility to be accurate about such comparisons.”
[…]
“So you can ask, ‘Okay, well, how many geographically widespread, abundant, durably skeletonized marine taxa have gone extinct thus far?’ And the answer is, pretty close to zero,” Erwin pointed out. In fact, of the best-assessed groups of modern animals—like stony corals, amphibians, birds and mammals—somewhere between 0 and 1 percent of species have gone extinct in recent human history. By comparison, the hellscape of End-Permian mass extinction claimed upwards of 90 percent of all species on earth.
[…]
The Atlantic and WUWT
Note that the “Big 5” and other real extinction events put significant dents into the number of genera and how biodiversity has literally exploded since the end of the Jurassic Period:
The K-T (End-Cretaceous mass extinction) was just a “bump in the road” compared to the End-Permian extinction.
So, rather than whine about the occasional loss of a toad species that looks just like the un-endangered toad species in the next valley, we should celebrate the Carbon-Fed* Sixth Mass Genesis… We could even call it the Anthropocene Explosion!
*Pretty well all life on Earth is carbon-fed in one way or another.
I’ll just close with George Carlin’s best-ever standup routine…
(WARNING: Lots of F-bombs)…
Not to mention all the species and genera that are being created in labs.
New species and genera of both prokaryotes and eukaryotes have been made in the lab. Previously the prokaryotes were mainly bacteria, but now CRISPR technology allows more rapid mutation of archaea as well.
The model archaeon, Methanosarcina acetivorans, has a doubling time of eight to ten hours, as opposed to the model bacterium E. coli, which can double in about thirty minutes. So it’s a lot easier to generate mutations in bacteria than archaea. But CRISPR permits an end run around that limitation.
https://www.sciencedaily.com/releases/2017/03/170308092502.htm
Among eukaryotes, new species and genera have been created in labs for both unicells and all three multicellular kingdoms, ie plants, fungi and animals.
Yes the ‘anthropocene’ exists because of the relative warmth of the holocene allowed civilization.
Yup. During the previous Eemian Interglacial, which was even warmer than the Holocene, Anatomically Modern Humans were limited to Africa, where it was already warm.
But before the Holocene, we had already spread to all the continents except Antarctica. And New Zealand, if you consider it a continent, as some do, most of which is sunken of course.
One of my favorite propaganda taglines on this whole subject is ‘extinct in this area’.
Global populations notwithstanding.
“Locally extinct” and “extinct in the wild” ≠ Extinct
The correct term for local “extinction” is “extirpation”, but that can simply mean that the population has moved, without necessarily vanishing from a larger area.
The interglacial must have ‘extirpated’ many species from many areas, species that preferred cold areas. Many cold areas became warm since the start of the Holocene.
And the glacial after the Eemian must have ‘extirpated’ many ‘warm species’ from area’s that were loosing many degrees. Not to talk about the effects on species of the huge desertification that came together with the Glacial.
Nature adapts. And it is always adapting.
Wim,
A good example of extirpation was of the straight-tusked elephant from most of Europe as conditions worsened during the last glaciation. It was a forest creature, so was driven south as steppe tundra spread across northern Europe. Its last stand was in Portugal some 30,000 years ago, where it was finished off by modern human hunters.
It finally went extinct during the LGM, throughout its range, in western Asia as well as Europe. Its genome was sequenced last year, showing it more closely related to the living African forest elephant than the former is to the African bush elephant. It had previously been considered closer to the Asian elephant, based upon anatomical similarities and its range.
https://en.wikipedia.org/wiki/Straight-tusked_elephant#Dwarfed_descendants
But humans too were extirpated from northwestern Europe during the LGM, seeking refuge in SW France, where the Solutrean culture developed.
Yeah, they will judge a squirrel rare on one side of the Rocky Mountains while it is a common pest on the other side. The “rare” part is just the ecological limit being described for their territory.
After mass extinctions come “explosions”, as the surviving forms adapt and radiate into vacant niches.
The most famous such explosion was the Cambrian, which followed the mass extinction of the Ediacaran biota. But it’s now common also to speak of the Triassic Explosion, which followed the “Great Dying” at the end of the Permian Period. The adaptive radiation of mammals, birds and some other vertebrates after the end Cretaceous mass extinction was also explosive.
Gaybro,
Didn’t you here what Charles said to me the other day?
” It has been a longstanding policy on this site to avoid certain conflict-ridden conflicts, such as evolution, intelligent design, middle east conflict, religion.”
And what he said to you when you questioned the policy?
“Because discussions of evolution spawn discussions of religious faith, theism vs. atheism and a lot of ignorant sniping. So it is better to leave it alone. I don’t want people of faith attacking you, and I don’t want you attacking people of faith.”
Now, I figure the odds against him “steering” you away from discussing evolution are roughly the same as the odds against spontaneous generation of a living organism, because I don’t believe he believes there’s a chance in hell that a creationist is going to “attack” you for speaking about evolution . . So, I guess I’ll just thank him for thinking of the well being of creationists, and leave it there ; )
JohnKnight,
While I can understand that you feel you are being treated unfairly, the “Gaybro” was uncalled for!
I would tend to think that a discussion of mass extinction sort of assumes evolution. A creationist presumably just dismisses the whole concept, references Noah’s ark, and walks away.
John,
How exactly do you propose to discuss the fact of extinction without also discussing the fact of evolution?
Until Charles or Anth@ny personally tell me not to discuss science on a science blog, I’ll keep commenting on science here.
Creationism, OYOH, is not science, so has no place here IMO. But it’s not my blog.
Clyde,
[snip, rude and uncalled for]
If WUWT banned discussion of the scientific fact of evolution, it would lose all credibility as a science site.
Doing so would confirm climastrologists’ charge that skeptics are against all science, not just “climate science”, but biology, geology, physics, chemistry, meteorology and astronomy. Read literally, the Bible opposes all science, not just evolution, paleontology, geology, etc. In fact, it’s easier to interpret evolution into biblical passages than it is modern astronomy.
I wouldn’t say that “read literally, the Bible *opposes* all science.” However, the Bible, read literally, isn’t science. There are people who oppose science on the basis of literal reading of the Bible. And there are “scientists” who seem unaware of the definition of “scientific theory.”
Scientific theories always have to be open to challenges and debate; orherwise it ceases to be science.
I was tempted to post a thread about the recent decision of the US NPS to allow a YEC geologist a permit to collect rock samples from the Grand Canyon… but I envisioned the comments section turning into a flame war.
Reply: Thank you~ctm
Back a ya! Thank you for putting out the fires
[no…we are not going to have a Bible vs Science argument. I do not want to have to look over your shoulders all day so…JUST STOP IT!] ~ctm
I didn’t realize I spelled it that way, Clyde . . I’m a phonetics guy, and that’s how my mind reads ‘Gabro’. It’s got nothing at all to do with sexual anything to me . .
Gabro,
“How exactly do you propose to discuss the fact of extinction without also discussing the fact of evolution?”
Any way you want, same as me. Freedom of speech, freedom of the mind . . .
And, in that spirit, I hereby bitch about you once again speaking of mere “evolution”, as though it doesn’t have a host of potential meanings, the vast majority of which are not in any sense (I can fathom) contradictory to creationism/ID etc. It appears to me to be virtually identical to the way climate alarmists speak of “climate change”, in what to me is obfuscation, not meaningful dialog (or freedom of the mind).
I’ve never seen a single human being (or book ; ) advocate for the proposition that living things can’t/don’t gradually change, just as I’ve never seen a single human being advocate for the proposition that climate is (or was ; ) unchanging. And, I don’t believe it’s entirely coincidental that these two word games exist. I believe both were intentionally “nurtured” by people who want to shut down any skeptical discussion about the underlying theories involved.
[another person who’s not getting it. I am stopping the religious vs non-religious debate, the Bible vs. Science debate, the Creation vs. Evolution debate. Evolution is an accepted modern science topic. This is a science blog. Discussion and derivation of its aspects is fine. What is not acceptable to me is the petty sniping between various philosophical factions, those of faith and those of materialism. So I strongly recommend that those of faith do not initiate these conflicts, but I also will censor rude treatment directed at people of faith.~ctm]
JohnKnight July 15, 2017 at 2:33 pm
There is no word game with regard to biological evolution, or chemical, geological, physical or astronomical for that matter. In biology, evolution means the change in genetic composition of a population of organisms over successive generations. A plethora of evolutionary processes cause these genetic changes. Also in biology, but in a number of other sciences as well, such as paleontology, geology, anthropology, etc, it too means the sequence of events in the development of a clade or lineage of organisms.
[stop with the insults. In fact JUST STOP~ctm]
You seem to imagine that biological evolution is always gradual. It isn’t. Even in the case of the evolution of new species (speciation), most evolution occurs in a single generation. Specialists disagree over the relative importance of quick and dirty evolutionary processes, such as hybridization or polyploidy, vs. more gradual ones, such as most natural selection.
But the fact is that evolution occurs in every single generation of every organism on the planet. It cannot help but happen, given the genetic code and laws of inheritance. So, naturally, it is observed every day in every way, everywhere around us on earth.
CTM,
Clearly it is you who don’t get it. There is no such debate as you imagine. Evolution is a scientific fact, not “materialism”.
John Knight objected on religious grounds to a perfectly uncontroversial scientific statement by Gabro and called him “Gaybro”, yet you think creationists are those who need defending here.
Have you considered the use to which Mann, et al will put your banning discussion of evolution on this ostensible science blog?
I appreciate the sacrifice you’re making for Anth*ny, but maybe you should check with him before destroying the reputation of his blog.
Reply: Read what I wrote. I’m not banning discussions of evolution. I’m banning debates over evolution vs creationism. Both sides in those debates tend to be disrespectful and contentious.~ctm
No, it is more of a philosophic principle that it is better to argue with someone who you are convinced is in error than to just tell him to shut up and listen to his betters. JK is reasonable on some subjects, but is curiously unwilling to learn any real biology.
Charles is 100% correct here. Had I known that a thread about extinction would devolve into a C vs E flame war, I wouldn’t have posted it.
[try again. read what I wrote carefully~ctm]
[When you can comment without being insulting you can comment~ctm]
[Really? You think that’s the way to score points?~ctm]
CTM,
Not trying to score points. Just pointing out to you the fact of your blatant hypocrisy and total misunderstanding of biology in particular and science in general.
Reply: Love you too. I’ll admit to being somewhat out of date. Last I was looking into it the big debate was between Gould’s Punctuated Equilibrium and Gradualism. I’m sure molecular biology has upped the game since.~ctm
CTM,
Anyone who imagines that there is a scientific debate about evolution between people of faith and materialists is not only not up to date, but totally out to lunch.
Reply: Your lack of reading comprehension continues. I never said anything such as that. I suggest you take a breath. I wish to prevent C vs. E debates from occurring on this site when I see them occurring. I tell both sides not to do it. A couple of days ago your opponent thought I was coming down on him. To me this is evidence that I am steering the correct course. Neither side thinks I’m with them.~ctm
David Middleton July 15, 2017 at 1:32 pm
Just shows yet again that this isn’t a science site but a creationist swamp.
Charles, you’re so divorced from scientific reality that you don’t even know how far out you are.
The reading comprehension problem is yours, not mine. You have failed to read even the most elementary science texts.
Sorry that what could have been a useful blog has been shown antiscientific garbage. Much as it pains me to admit, the CACA adherents were right all along that some skeptics are anti-science.
Willy,
“[another person who’s not getting it. I am stopping the religious vs non-religious debate, the Bible vs. Science debate, the Creation vs. Evolution debate. Evolution is an accepted modern science topic”
[snip. What part of stop, do you not understand?~ctm]
(Sir, another person said something and I responded. I highly resent your (to me) selective enforcement of some vague rule that allows anyone who feels like it, to present their views on the matter, as long as they conform to . . yours, apparently)
Reply: He did it first! isn’t going to fly when I’ve spent the day telling you all to stop. Stop means stop.~ctm
“Reply: He did it first! isn’t going to fly when I’ve spent the day telling you all to stop.”
How dare you accuse me of such a childish appeal? It never happened . . though with you chopping off (to my mind) perfectly innocuous statements I made, I can’t demonstrate that it did not happen. I say it’s just you, imagining things . . again. .
Any blog which does not subject creationists to scathing ridicule and the public humiliation they so richly merit is no science site at all.
Reply: I’ll try this one more time.
I don’t like creationists/ID types gumming up discussions of biology.
I don’t like scientific materialists/militant atheists insulting people of faith.
Keep it up and I’ll start trashing all your comments.
~ctm
CMT,
You’ve shown great patience.
This is “Anthony’s living room” and you’re house-sitting for him.
A question. (No need to cringe.8-)
If one hit “Contact” under the title bar’s drop-down, would you see it or would only Anthony see it?
I don’t want to add his “In Box” when he returns if I only want to email you.
“[another person who’s not getting it. I am stopping the religious vs non-religious debate, the Bible vs. Science debate, the Creation vs. Evolution debate. Evolution is an accepted modern science topic. This is a science blog. Discussion and derivation of its aspects is fine. What is not acceptable to me is the petty sniping between various philosophical factions, those of faith and those of materialism. So I strongly recommend that those of faith do not initiate these conflicts, but I also will censor rude treatment directed at people of faith.~ctm]”
I don’t get it either.
Under your strictures, how is it possible to mention evolution at all, since the mere idea offends “those of faith”? Why do you care about people’s religious beliefs on an alleged science blog? Why do people who believe in creationism for religious reasons, since there it lacks scientific basis, get to censor discussion of science on an ostensibly scientific Web site?
How does discussing evolution make one a “materialist” or “militant atheist”? All the largest Christian denominations recognize the reality of evolution. Only a few Evangelical sects and cults can’t handle the truth. Many biologists of my acquaintance are practicing Christians and Jews.
Sorry, but your rule makes no sense. It in effect bans discussion of evolution.
Reply: It’s about stopping discussion about the reality of evolution, not the details.~ctm
“Makes no sence”? Sure it does. “The science is settled.” “The debate is over.”
But I don’t believe that’s the attitude CMT is taking, as a Mod, in Anthony’s living room. He’s just trying to prevent a “food fight”.
Give him a break.
(I read the beginning of this sub-thread but didn’t have time to comment. When I did have time and saw where it was going, I put down my pie.)
As it is such a good theme for fund raising, the “sixth mass extinction” will not go away.
As of several years ago, it appeared that 15 birds and mammals had gone extinct in the last 100 years (none to habitat loss not on an island), but 9 species had been discovered that they had thought to be extinct, so we are only down 6 species. Actually, I might have this backward in which we are actually up 6 species. Regardless, it is nothing to speak of in biological circles. Nothing happening here, folks, move along.
“*Pretty well all life on Earth is carbon-fed in one way or another.”
One way to define life itself would be the exchange of Carbon from one Carbon Based Life Form to another, traced back to the base of the food chain – Carbon Dioxide.
Carbon Dioxide is required for the Carbon Cycle of Life to complete.
On Earth, CO2 isn’t absolutely necessary, at least theoretically, but carbon and oxygen are. Also hydrogen, nitrogen and phosphorus. These are the components of nucleic and amino acids. For more complex structures and metabolisms, some other elements are required as well, of course.
Carbon is just about ideal for biochemistry.
Are you familiar with the Carbon Cycle? … Carbon Dioxide is “absolutely necessary”
Some life may get their carbon from CH4 and other sources.
Right you are.
Hence the name methanotrophs!
Lots of prokaryotes make their livings solely off CH4. No CO2 need apply.
Is there an acronym or mnemonic sentence to remember the initial letters of the names from Domain through species?
Ignoring domain, there’s “King Philip Cried, ‘Oh, For God’s Sake.”
S G F O C Ph K D looks kind of nasty.
https://www.mnemonic-device.com/biology/taxonomy/domain-kingdom-phylum-class-order-family-genus-species/
Linnean taxonomy has been supplanted but not fully replaced by cladistic phylogeny.
Actually there are quite a few of them:
https://www.mnemonic-device.com/biology/taxonomy/domain-kingdom-phylum-class-order-family-genus-species/
I don’t know, but there’s a good one for the order of sharps to be added in musical key signatures (F C G D A E B): Father Carson’s Grandmother Died After Eating Beans. I learned that from a student over fifty years ago. Mnemonics can be fun . . .
I thought only cute and fuzzy animals could go extinct due to man.
Maybe smallpox is cute and fuzzy
At most, there are a couple hundred documented cases of species extinction over the last 200 years.
And none of them were due to climate.
Over hunting and being out competed by invasive species account for almost all of the extinction events.
PS: A non-trivial number of species that have been declared extinct were later found alive and well, just deeper in the jungle.
“found alive and well, just deeper in the jungle”
Smart species.
“Mass Extinction” — it just has a nice alarming ring to it.
I try to imagine alternative phrases, and they just don’t work as well. For example:
“Awesome Extinction”
“Grand Extinction”
“Amazing Extinction”
“Phenomenal Extinction”
“Big Ol’ Extinction”
“Helluva Extinction”
“Fabulously Large Extinction”
See? Just not the same effect.
Don’t get me started on “Anthropocene” again.
Stinkin’ Big ‘stinction?
Why is everybody always blaming the Catholics? 😎
Now that is funny.
Kind of. Or maybe it’s just my sense of humor.
OMG…REAL science from NASA…awesome !!
“NASA’s Juno probe images Jupiter’s Great Red Spot”
http://video.foxnews.com/v/5507968108001/?#sp=show-clips
The claim that the current extinction rate is nothing to worry about because it is only effecting species
and not genera or higher levels of classifications seems wrong for two reasons. Firstly only species are
important in an evolutionary sense. Other classifications are far more arbitrary and are of far less importance. Secondly if species continue to go extinct at the rate shown in the figure above how long do you think it will be before genera and whole families go extinct? Mass extinctions start at the species level and species have to go extinct before a genera can go extinct.
Geronimo,
You said, ” Firstly only species are important in an evolutionary sense. Other classifications are far more arbitrary and are of far less importance.” Do you have someone of authority you can cite that agrees with you?
You also said, “Secondly if species continue to go extinct at the rate shown in the figure above how long do you think it will be before genera and whole families go extinct?” There are extant genera for which only one or two species continue to survive. So, your implication that losing species will doom a genus is without support.
Lastly, “extinct” is a state of being, not an activity. That is I can GO fishing, or skating. However, the process of extinction leads to a life form becoming extinct. Saying something “went extinct” or “will go extinct” is just poor grammar.
I’m reminded of a quote from Einstein: “Whoever is careless with the truth in small matters cannot be trusted with important matters:“
As of 2010 biologists had classified and described approx. 1.9 million plants and animals species.
Estimates of the total number of species on earth run between 7 and 8.5 million.
Seems to me Homo Sapiens collectively will have to make far more of an effort to make a “mass extinction” level dent in that number – in particular if we are working on achieving said mass extinction by way of anthropogenic CO2…
Well, eventually we will run out of isolated islands and such that have local spiciest that can’t complete with the continental species stowing away on human transport.
The key point is that you need to see 90% or more of all species going extinct before you can call it a “mass extinction” event. What we are seeing is nothing more than the normal background level of extinctions happening.
I have long held that the main problem is not the extinctions, but the new species. That is, scientists are “creating” far too many new species. It just needs for the new “species” to look a little different & the biologist will claim naming rights. Note that there is no credit for finding a new race in an existing species. So an isolated pool of water can dry up & a “species” will become extinct. But on the adjacent hill, an almost identical “species” will still be living happily.
Long story short, a lot of these extinctions aren’t really so.
True. Even lost subspecies now count as “extinctions”.
Whole orders have been on the way out for a long time, as they always are. Perissodactyls have been losing out to competition from artiodactyls since the Oligocene, as grasslands have replaced forests in a cooling and drying world. Rhinos in particular have been hard hit. They were giants in the balmy Eocene and early Oligocene.
Geronimo,
In a true mass extinction event, the vast majority of species go extinct, along with many genera, families, orders and even classes and subphyla. I can’t think of an instance of a phylum going extinct in the Phanerozoic MEEs, but also can’t swear it hasn’t happened.
In the Permian MEE, even insects were hard hit. Eight or nine insect orders went extinct and ten more greatly reduced in diversity. But marine invertebrates were hammered the hardest. Vertebrates on land and sea suffered as well, to include an entire class of fish. Two thirds of terrestrial vertebrate families went extinct.
While classifications above species are to some extent arbitrary, by any measure a MEE is another whole thing from what is happening now. For that matter, what counts as a “species” can also be pretty arbitrary.
Think about a tree, that weight of the wood, heavy, well all that wood is carbon based and it all blew in on the wind, the carbon was not absorbed thru the roots, but thru the leaves, wood blows on the wind as C02
Never fail to love George Carlin. He may be dead, but he’s still relevant.
One of the often cited problems for critters is habitat loss. On the other hand, critters do adapt to human habitats and increase their range in surprising ways. link Of course the alarmists think that’s a problem …
If you had asked me thirty years ago if we’d ever see coyotes in urban areas I would have confidently predicted that would never happen. Coyotes are just too wary. Okay then …
The Thylacinus,or Tasmanian Tiger was wiped out by having a bounty put on its head up to the 1920’s and being systematically shot. The last Tasmanian tiger, called Benjamin, died in captivity in on September 7, 1936 at Hobart Zoo after being left out in the cold. The Thylacine was closely related to the still living Tiger Quoll.
Was the Tasmanian Tiger also known as the Tasmanian Wolf?
I thought they were two different critters. Years ago I remember reading that the last Tasmanian Wolf died in a zoo.
(My memory may be at fault.)
Same animal. Tasmanian wolf and tiger are both common names for the thylacine.
I hate to keep picking on Sigma Xi because their last American Scientist looked good, but they sent this out as their link to this paper. For a scientific honor society to be using cbsnews as a source does not help their credibility or serious attempts at conservation.
http://www.cbsnews.com/news/sixth-mass-extinction-biological-annihilation/ based on this paper by familiar people.
“Biological annihilation via the ongoing sixth mass extinction signaled by vertebrate population losses and declines” http://www.pnas.org/content/early/2017/07/05/1704949114.full
From CBS
“This steady stream of species loss, about two extinctions per year, hardly makes a blip on the public’s radar. In many cases, that’s because the losses are obscure: recent extinctions include Mexico’s Catarina pupfish or the Christmas Island pipistrelle bat, hardly household names.”
At 2 a year how does that compare with what we are still finding per year?
CBS’ graph, figure 5 in the paper, shows some strange patterns. New World looks good relative to Old World. Real analyses of this paper will be interesting given statements like this —
“Here we extend investigation of mass extinction to terrestrial vertebrate population decreases and losses, and give estimates of the number of their species with decreasing populations. The accuracy of the estimates is strongly dependent on an unknown parameter, namely, the actual average area occupied by a vertebrate population.” and
“Population extinctions today are orders of magnitude more frequent than species extinctions.”
That’s nothing compared to individual extinctions. I ate a tuna salad today.
Three bumble bees from Europe!!!
Brexit did not happen soon enough.
1. Wouldn’t it be the 7th mass genius?
2. “Poisoning the Planet” with our 90,000 manmade chemicals accumulating in all sorts of uncomfortable ecosystems, external and internal, never seems to get much attention. Why is that?
Fear of “Incitement to Riot” charges, or “No worries, Mate”? Depends on trust, doesn’t it?
Seriously lacking in the pronouncements of our Glorious Gropenfuhrer and his Ignoranti?
The picture of a hockey-graph extinction tells me that Professor Mann and his friends now dabble in biology. Where can I find a list of extinct species from which the graph was drawn?
The problem that is not being discussed is the huge decline in natural wildlife populations. As the number of people in the world increases, and as their domesticated animals increase even faster, natural populations decline through resource appropriation by humans. The decline in population involves a genetic loss and an increase in species and ecosystems frailty. Extinction is just the final act. Impoverishment of natural resources is the problem that needs to be fought with determination now. We need to stop expanding and give wildlife more room. The increase in CO2 can do the rest.
I suggest the reading of:
Barnosky, A. D. (2008). Megafauna biomass tradeoff as a driver of Quaternary and future extinctions. Proceedings of the National Academy of Sciences, 105(Supplement 1), 11543-11548.
http://www.pnas.org/content/105/Supplement_1/11543.full
Javier,
Habitat has increased for many wild species since Europeans colonized North America. There are more coyotes and white tail deer now than ever before, for instance. Others, granted, have gone extinct.
That’s just evolution in action.
It would be interesting to re-cast the graph of species #s vs geological time & look at extinctions as a percent of total species- the big 5 would look much more profound & any current day losses look pretty minuscule
Unless you think on geological time-scales Jeff, then you’re comparing oranges with oranges and the current extinction rate possibly dwarfs any proceeding.
Tony,
Dwarf. Hmmm.
Not even close. You’re off by orders of magnitude.
As usual.
Homo Sapiens is already extinct, all that remain are Homo Stultus.
What is the optimal number of species? The more, the merrier? It’s just a biologist’s dream. Extinction is part of natural selection. The dominant species selects. We breed plants and animals useful to us. Don’t destroy forests and poison the sea and fresh waters. Keep endangered species in zoos to prevent their extinction. If species still die, what’s the big deal? It always happen in natural history.
Let us consider that of the largest animal species have only apared on earth after man, consider the bigfoot, the chupacabra, and at least 4 spices of big cat that now exist in Britain
The total number of species on the planet isn’t a particularly good measure of biosphere health, particularly considering its dependence on geographical isolation. Frankly, it would more enlightening to look at some estimate of total biomass.
Particularly since the definition of “species” is quite expansive.
Yet the regulation agencies have got away with stopping development, farming and other business activity because they found a snail or fish they deemed endangered in a local area.
Without humans on Earth species would be going extinct and evolving into new species probably at about the same rate they are today. Some of the species are on the verge of extinction regardless of humans and will go extinct now matter what humans do. Sure we have pushed some over the edge but often they were on the decline anyway. Just like death is the end result of life, extinction is the ultimate end for a species. The idea of species are a human invention. We make really dumb decisions supposedly trying to avoid a species or subspecies going extinct. What is ironic is that after bringing raptors back from the brink in the USA, the USFWS has issued a “take permit” for wind farms across the USA. Present wind farms kill between 100K and 325K per year. One wind farm in the late great golden state, in operation for 25 years, has killed 2,900 golden eagles alone.
I think humans clearly accelerate this process. We accelerate or retard a lot of processes.
All lifeforms do this. We just happen to be the only lifeforms, so aware of our own impacts, that some of us are willing to commt economic suicide in order to erase our footprint.
Nice piece, although an article on verbal accuracy is diminished by “biodiversity has literally exploded since the end of the Jurassic Period”.
I don’t see how the numbers of animals can increase if they keep exploding, wouldn’t they diminish? Perhaps they only explode after they have passed reproductive age? Nature’s version of menopause?
I hope the author meant “metaphorically exploded”, although the picture of beasties spontaneously exploding as they amble along is amusingly Pythonesque.
I was more going for Douglas Adams-esque
The Bird Mass Extinction
A few comments on C vs E…
There is no “debate,” just a flame war. (Thank you Charles, for hitting it with a fire hose).
This particular argument is ridiculous: “It’s just a theory,” vs “No! It’s a fact!”
In science, there is no hierarchy from theory to fact. A scientific theory is a systematic, comprehensive, predictive explanation of the facts (observations). Scientific theories are so powerful, they can predict as-yet unobserved facts. The scientific theory of evolution is one of the most powerful, robust, comprehensive and predictive theories ever devised by man.
To refer to it as “just a theory” or to insist that it has somehow been promoted from theory to fact belies an ignorance of the concept of scientific theory.
Directly-observed genetic evolutionary processes are facts (observations).
The fossil record consists of facts (observations).
The integration of these two sets of facts, combined with basic principles of geology and geochronology leads to the scientific theory of evolution.
Regarding punctuated equilibrium (punk eke) vs slow genetic drift, the fossil record clearly supports punk eke.
Evolution is a fact as well as a theory explaining that fact. That the fact and the theory have the same name doesn’t imply a hierarchy. Similarly, there are the fact of gravity and the theory of universal gravitation.
Speciation and the formation of new genera have been observed, indeed new species and genera are created in labs as well as in nature. So evolution is a fact.
Some other evolutionary events and processes which have been inferred from other facts, as per your comment.
Gradual evolution doesn’t occur only via genetic drift, but from processes such as natural selection as well.
Punctuated equilibrium occurs, but it’s not the main tempo or mode of evolution. Rapid evolution can be followed by long intervals of gradual evolutionary change. Just as modern geology includes both catastrophism and uniformitarianism, modern biology recognizes both periods of rapid and gradual change.
Human evolution provides instances of both rapid and gradual change. Single mutations are responsible both for upright walking and brain enlargement, but both developments then underwent further evolution. The pelvises, legs and feet of our ancestors gradually became better adapted to bipedalism. And after the change in the brain growth gene, our ancestors’ cerebral volume increased a slow, steady pace for over a million years.
The inability to grasp the difference between observations of evolutionary processes and the overarching scientific theory of evolution is fundamentally unscientific.
David,
I beg to disagree.
For Darwin, the origin of species was evolution, although he never used that term himself.
Hence, speciation is evolution. And speciation has been observed hundreds if not thousands of times. Thus, evolution is an observation, that is, a scientific fact.
It’s common for scientific theories to be named for the facts which they try to explain. Besides the theories of gravity and evolution, there are for instance the germ theory of disease and the atomic theory of matter.
What is now called evolution, in the sense of the history of life on earth, was known as “development” in the early 19th century, that is, the observation or scientific fact that fossil assemblages change dramatically in rocks of different ages, generally from simpler to more complex and diverse, with interruptions.
In the sense of the origin of species by descent with modification via natural selection and other evolutionary processes, it was then called “transmutation”, and generally rejected by natural philosophers for lack of a plausible mechanism, which of course Darwin and Wallace provided with their discovery of natural selection.
Which is one of the most eloquent, robust scientific theories ever devised by man.
David,
Yes, of course evolution is a theory, comparable to the theory of universal gravitation, although it is much better understood than gravity.
But evolution also refers to the repeatedly observed fact of evolution, ie new species from existing species, as well as all the other evolutionary processes, such as the natural selection which has created the terrible problem of MRSA.
I looked for but could not find a clip from the episode of “Monk” that introduced Natalie Teeger as his new assistant.
The Captain held up a type of goldfish and wondered why someone would think it was valuable and try to steal it.
Lt Disher said, “Maybe it’s extinct.”
Captain Stottlemeyer replied, “How could it be extinct if we’re looking at it?”
(The clip was better.)
Gotta love Ted Levine as Leland Stottlemeyer.
You’re an idiot.
Bruce,
It’s unclear to me to whom you refer. If to David, then please be specific, lest I conclude that you are an idiot. Because he’s right.
I’m tired tonight and I’m going to close this thread for a day or so while I compose a solid answer to the burning question.