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Super Volcano Will Challenge Civilization, Geologists Warn
SPACE.com ^ | March 8, 2005 | Robert Roy Britt

Posted on 03/08/2005 4:16:02 AM PST by AntiGuv

The eruption of a super volcano "sooner or later" will chill the planet and threaten human civilization, British scientists warned Tuesday.

And now the bad news: There's not much anyone can do about it.

Several volcanoes around the world are capable of gigantic eruptions unlike anything witnessed in recorded history, based on geologic evidence of past events, the scientists said. Such eruptions would dwarf those of Mount St. Helens, Krakatoa, Pinatubo and anything else going back dozens of millennia.

"Super-eruptions are up to hundreds of times larger than these," said Stephen Self of the United Kingdom’s (U.K.) Open University.

"An area the size of North America can be devastated, and pronounced deterioration of global climate would be expected for a few years following the eruption," Self said. "They could result in the devastation of world agriculture, severe disruption of food supplies, and mass starvation. These effects could be sufficiently severe to threaten the fabric of civilization."

Self and his colleagues at the Geological Society of London presented their report to the U.K. Government's Natural Hazard Working Group.

"Although very rare these events are inevitable, and at some point in the future humans will be faced with dealing with and surviving a super eruption," Stephen Sparks of the University of Bristol told LiveScience in advance of Tuesday's announcement.

Supporting evidence

The warning is not new. Geologists in the United States detailed a similar scenario in 2001, when they found evidence suggesting volcanic activity in Yellowstone National Park will eventually lead to a colossal eruption. Half the United States will be covered in ash up to 3 feet (1 meter) deep, according to a study published in the journal Earth and Planetary Science Letters.

Explosions of this magnitude "happen about every 600,000 years at Yellowstone," says Chuck Wicks of the U.S. Geological Survey, who has studied the possibilities in separate work. "And it's been about 620,000 years since the last super explosive eruption there."

Past volcanic catastrophes at Yellowstone and elsewhere remain evident as giant collapsed basins called calderas.

A super eruption is a scaled up version of a typical volcanic outburst, Sparks explained. Each is caused by a rising and growing chamber of hot molten rock known as magma.

"In super eruptions the magma chamber is huge," Sparks said. The eruption is rapid, occurring in a matter of days. "When the magma erupts the overlying rocks collapse into the chamber, which has reduced its pressure due to the eruption. The collapse forms the huge crater."

The eruption pumps dust and chemicals into the atmosphere for years, screening the Sun and cooling the planet. Earth is plunged into a perpetual winter, some models predict, causing plant and animal species disappear forever.

"The whole of a continent might be covered by ash, which might take many years -- possibly decades -- to erode away and for vegetation to recover," Sparks said.

Yellowstone may be winding down geologically, experts say. But they believe it harbors at least one final punch. Globally, there are still plenty of possibilities for super volcano eruptions, even as Earth quiets down over the long haul of its 4.5-billion-year existence.

"The Earth is of course losing energy, but at a very slow rate, and the effects are only really noticeable over billions rather than millions of years," Sparks said.

Human impact

The odds of a globally destructive volcano explosion in any given century are extremely low, and no scientist can say when the next one will occur. But the chances are five to 10 times greater than a globally destructive asteroid impact, according to the new British report.

The next super eruption, whenever it occurs, might not be the first one humans have dealt with.

About 74,000 years ago, in what is now Sumatra, a volcano called Toba blew with a force estimated at 10,000 times that of Mount St. Helens. Ash darkened the sky all around the planet. Temperatures plummeted by up to 21 degrees at higher latitudes, according to research by Michael Rampino, a biologist and geologist at New York University.

Rampino has estimated three-quarters of the plant species in the Northern Hemisphere perished.

Stanley Ambrose, an anthropologist at the University of Illinois, suggested in 1998 that Rampino's work might explain a curious bottleneck in human evolution: The blueprints of life for all humans -- DNA -- are remarkably similar given that our species branched off from the rest of the primate family tree a few million years ago.

Ambrose has said early humans were perhaps pushed to the edge of extinction after the Toba eruption -- around the same time folks got serious about art and tool making. Perhaps only a few thousand survived. Humans today would all be descended from these few, and in terms of the genetic code, not a whole lot would change in 74,000 years.

Sitting ducks

Based on the latest evidence, eruptions the size of the giant Yellowstone and Toba events occur at least every 100,000 years, Sparks said, "and it could be as high as every 50,000 years. There are smaller but nevertheless huge eruptions which would have continental to global consequences every 5,000 years or so."

Unlike other threats to mankind -- asteroids, nuclear attacks and global warming to name a few -- there's little to be done about a super volcano.

"While it may in future be possible to deflect asteroids or somehow avoid their impact, even science fiction cannot produce a credible mechanism for averting a super eruption," the new report states. "No strategies can be envisaged for reducing the power of major volcanic eruptions."

The Geological Society of London has issued similar warnings going back to 2000. The scientists this week called for more funding to investigate further the history of super eruptions and their likely effects on the planet and on modern society.

"Sooner or later a super eruption will happen on Earth and this issue also demands serious attention," the report concludes.


TOPICS: Culture/Society; Miscellaneous; News/Current Events
KEYWORDS: archaeology; callingartbell; climatechange; ggg; godsgravesglyphs; history; supervolcano; theskyisfalling; weredoomed
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To: AntiGuv

Damn we better heat the earth up so it won't get so cold, eh?


81 posted on 03/08/2005 8:04:16 AM PST by justshutupandtakeit (Public Enemy #1, the RATmedia.)
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To: AntiGuv
"While it may in future be possible to deflect asteroids or somehow avoid their impact, even science fiction cannot produce a credible mechanism for averting a super eruption," the new report states. "No strategies can be envisaged for reducing the power of major volcanic eruptions."

I guess this guy has never heard of a pressure relief valve?

82 posted on 03/08/2005 8:05:30 AM PST by null and void (The Pendragon Production of H.G. Wells' War of the Worlds opens March 30th. Be there or be eaten...)
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To: AntiGuv
Past volcanic catastrophes at Yellowstone and elsewhere remain evident as giant collapsed basins called calderas.

We went out to Yellowstone back in 2003. It's interesting to look at the map given out by the Park Service. It shows the outline of the caldera on it, and you can see the physical changes in the landscape as you cross those boundaries. As you cross into the caldera, the vegetation is much more sparse, and there are little vents now and then that release steam in an almost constant stream. Most interesting are the little outcoppings that have formed in Yellowstone Lake. Some are like little islands and they are SMOKING! You can see, especially in the shallow areas on the edge of the lake, vents under the water that are continually releasing hot air. They bubble constantly!

83 posted on 03/08/2005 8:15:29 AM PST by SuziQ
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To: Kretek
I think it's just called Supervolcano (but it may have a subtitle, like "disaster at Yellowstone" or some such). It's a BBC movie and is supposed to be shown over here on a regular US cable channel, like Discovery, not on BBC America....

Googled "bbc supervolcano" and the second hit was the BBC blurb on the show:

Supervolcano

The beauty of America's Yellowstone National Park masks one of the rarest and most destructive forces on Earth - a supervolcano.

A new two-part BBC factual drama asks: 'What if Yellowstone erupted?'

Parts 1 & 2: 13-14 March, 9pm BBC One

No listing on network or timing for US broadcast there.

Here's another hit from that same google search:

Yellowstone Supervolcano Drama on BBC this Month
By James Wray Mar 4, 2005, 08:55 GMT

which has more detail on the program.  It does state that it is co-produced by BBC and Discovery (among others) so I guess that means it's going to be on Discovery.

84 posted on 03/08/2005 8:53:38 AM PST by Phsstpok ("When you don't know where you are, but you don't care, you're not lost, you're exploring.")
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To: Phsstpok
Thanks for the information! I'll keep an eye out.
85 posted on 03/08/2005 8:59:14 AM PST by Kretek
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To: AntiGuv

We must increase our destruction of the South American rain forests post haste so that we may begin growing our crops down there.


86 posted on 03/08/2005 9:06:33 AM PST by GunnyHartman (Allah is allah outta virgins.)
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To: AaronInCarolina
Here I am to save the day!!!!

I thought it was "Here I come to save the day!"

87 posted on 03/08/2005 9:45:42 AM PST by laker_dad
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To: laker_dad
I thought it was "Here I come to save the day!"

You are probably correct. I hesitated before posting it because I couldn't remember if it was "am" or "come". Its been quite a while since I heard that little musical phrase.
88 posted on 03/08/2005 10:10:31 AM PST by AaronInCarolina
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To: Phsstpok
...so I guess that means it's going to be on Discovery.

Beware of specials on Discovery. Right after the Indian Ocean Tsunami, The Discovery Channel ran a special several times that made irresponsible sensational claims about a volcano, Cumbre Vieja, on the island of La Palma in the Canary Islands off the coase of North Africa. In the special, they claimed that a side of the volcano could suffer a landslide which would spur a "mega-tsunami" that would deluge the whole East Coast of America. They were claiming the wave from such a tsunami could reach 300 feet at Miami, FL. They said it would dwarf the earthquake-generated Indian Ocean tsunami. This is absolute hogwash, according to all but a handful of geologists. The "Tsunami Society" was very critical of such claims. Yet Discovery ran with it over and over because it was sensationalized by the Indian Ocean tsunami. They needlessly scared a lot of people to get a few more ratings points. I no longer trust the Discovey Channel.
89 posted on 03/08/2005 10:21:01 AM PST by AaronInCarolina
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To: AaronInCarolina

I saw that claim in other places. What's the truth?


90 posted on 03/08/2005 10:23:10 AM PST by Pyro7480 ("All my own perception of beauty both in majesty and simplicity is founded upon Our Lady." - Tolkien)
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To: AaronInCarolina

Actually, the Mega Tsunami science show isn't new. It was done several years ago and has been shown several times on Discovery Channel. Just like the several volcano shows and the earthquake shows, along with the asteroid impact shows and the existing Supervolcano science show from a few years ago.

It's also not hogwash. It's a recognized theory of cataclysmic events with a very strong base of geologic evidence, primarily backed up by research on and around the Hawaiin Islands.

Long run out avalanches, of the type found around the Hawaiin Islands, are established fact, not speculation. The estimates of the resulting tsunamis predicted specific impact signatures on the other islands and on both the mainland of North American and Asia. Many examples of the predicted signatures have been found.

USGS has contributed to this research for several years.


91 posted on 03/08/2005 10:30:06 AM PST by Phsstpok ("When you don't know where you are, but you don't care, you're not lost, you're exploring.")
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To: Phsstpok
It's also not hogwash.

I beg to differ. It is hogwash. Tsunamis are in reality a transference of ENERGY, and even more accurately, POWER. The amount of POWER created by a relatively finite slide of earth into the the ocean from above the ocean would be orders of magnitude less than the energy released by tectonic plates slipping against each other. The amount of energy and the power required to lift a volume of water 1000's of feet deep for 750 miles would in fact dwarf the power of a volume of dirt/rocks that measures probably less than 1 cubic km sliding relatively slowly into the sea, displacing surface water. Most scientists agree this would create a significant localized wave, but that wave would quickly dissipate due to lack of power/energy behind it.
92 posted on 03/08/2005 10:54:15 AM PST by AaronInCarolina
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To: AaronInCarolina
Here is the Tsunami Society's response to the claims made by the Discovery Channel special:

Tsunami Society Response
93 posted on 03/08/2005 11:06:43 AM PST by AaronInCarolina
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To: AntiGuv

Bookmark for later reading.


94 posted on 03/08/2005 11:07:43 AM PST by Betis70 (I'll drink no wine before it's quitting time)
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To: AntiGuv


We're doomed. Doomed! DOOMED!!!

95 posted on 03/08/2005 11:10:40 AM PST by Petronski (This is the Serengeti, heart of the Dark Continent, where Bar Codes roam free...)
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To: massgopguy

LOL


96 posted on 03/08/2005 11:13:19 AM PST by Petronski (This is the Serengeti, heart of the Dark Continent, where Bar Codes roam free...)
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To: elli1; blam
Thanks elli. I'll add it to the GGG catalog; seems to me there's a similar topic from last year, but I'm way too lazy to look for it right now. :')
Please FREEPMAIL me if you want on, off, or alter the "Gods, Graves, Glyphs" PING list --
Archaeology/Anthropology/Ancient Cultures/Artifacts/Antiquities, etc.
The GGG Digest
-- Gods, Graves, Glyphs (alpha order)

97 posted on 03/08/2005 11:50:22 AM PST by SunkenCiv (last updated my FreeRepublic profile on Sunday, February 20, 2005.)
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To: AaronInCarolina
Most scientists agree

Most scientists agree that such unsourced assertions are poppycock.

It is not a proven theory, but it is not disproven. Suggesting otherwise is silly.

Some of the early supporting evidence (and most spectacularly hyped claims) from work of Moore and Moore (1984 & 1988) dealing with fossil and shell deposits on Lanai has been adequately explained by uplift over the Hawaii hot spot. But nothing has been disproved.

The mathematical models vary widely about the energy in the collapse of volcanic islands, but the velocity estimates of 40 m/s (Ritter Island model) to 100 m/s (La Palma model) and the huge volumes involved clearly support the propositions that tsunamis (some huge) have occurred and will occur again from such events. Even 1,000 meter tall ones are possible at the outside edge of the models. Think 100 Mount St. Helens occuring at once and most of the volcano, with overall height from it's base greater than Mt Everest, is underwater.

Do you have the slightest idea of the energies involved in the collapse of, say, over half of the island that we now call Oahu unleashed? It left a scar that is at least 800 feet thick and covers nearly 9,000 square miles of the ocean bottom. Yes, the energy dissipated "rapidly" and the 200 foot wave did not extend far beyond the other Hawaiian islands, but it is estimated to have still been 65 feet high when it hit ancient California some 4 1/2 hours later.

The Christmas 2005 tsunami was 10 meters, or 30 feet, max, and it was considerably closer to the event, but earthquake generated tsunami's are limited by the maximum vertical displacement of the earthquake. It's this displacement and it's resultant kinetic energy that is important, not the underlying energy in the earthquake itself. A volcanic island collapse will have several orders of magnitude more inherent and kinetic energy involved than any earthquake ever envisioned.

Check out some university web sites, such as the College of Engineering, Department of Ocean Engineering at the University of Rhode Island, or the presentations at the NSF workshop, Hawaii 30th-31st May, 2003. Look at stuff by Stéphan Grilli, the work of Keating and McGuire, or Day and Ward. There is material that argues both sides, but it is REAL material, not bald assertions without any evidence to back it up.

So please stop making unsourced claims in a scientific debate like "most scientists agree," when they clearly don't.

I'm not a geologist, geophysicist, hydrologist or forensic scientist, nor do I play one on TV. I'm betting there probably are some such experts of each (or related scientific fields) available to us here on FR, but I'll bet pretty heavy that you aren't one.

My goodness! By definition we're on the internet. Can't you even hit Google and do a simple search before posting something? The questions are interesting. Trying to stifle the debate by dismissing things you don't understand as "hogwash" is really, really, boring.

98 posted on 03/08/2005 3:07:59 PM PST by Phsstpok ("When you don't know where you are, but you don't care, you're not lost, you're exploring.")
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To: TonyRo76; PatrickHenry; AntiGuv; docbnj
[...given that our species branched off from the rest of the primate family tree a few million years ago.]

Since when is that deluded Darwinian fantasy a "given"?

Since when? Since the overwhelming amount of evidence for that scenario relegated opposition to the same bucket of crackpots as flat-earthers and other folks too ignorant or stubborn to accept reality.

It was already clear from the fossil evidence alone, to anyone who cared to actually look at it (hint: Reading creationist hand-wavings about the fossils is not the same thing), but with the advent of detailed DNA analysis over the past several decades, the "debate" about human-ape common ancestry -- as well as the common ancestry of all life in general -- is *over*. The jury is in, and the evolution-deniers lost. It's just that many of them haven't bothered to learn enough about the topic to realize it -- or even have any kind of informed opinion about it. But that doesn't stop them from cockily spouting off about it anyway, as your post clearly shows.

Here's just a tiny taste of the *enormous* amounts of evidence, along multiple independently confirming lines, which show that humans and apes share a common ancestor (from previous posts of mine):

Background: Retroviruses reproduce by entering a cell of a host (like, say, a human), then embedding their own viral DNA into the cell's own DNA, which has the effect of adding a "recipe" for manufacturing more viruses to the cell's "instruction book". The cell then follows those instructions because it has no reason (or way) to "mistrust" the DNA instructions it contains. So the virus has converted the cell into a virus factory, and the new viruses leave the cell, and go find more cells to infect, etc.

However, every once in a while a virus's invasion plans don't function exactly as they should, and the virus's DNA (or portions of it) gets embedded into the cell's DNA in a "broken" manner. It's stuck into there, becoming part of the cell's DNA, but it's unable to produce new viruses. So there it remains, causing no harm. If this happens in a regular body cell, it just remains there for life as a "fossil" of the past infection and goes to the grave with the individual it's stuck in. All of us almost certainly contain countless such relics of the past viral infections we've fought off.

However... By chance this sometimes happens to a special cell in the body, a gametocyte cell that's one of the ones responsible for making sperm in males and egg cells in females, and if so subsequent sperm/eggs produced by that cell will contain copies of the "fossil" virus, since now it's just a portion of the entire DNA package of the cell. And once in a blue moon such a sperm or egg is lucky enough to be one of the few which participate in fertilization and are used to produce a child -- who will now inherit copies of the "fossilized" viral DNA in every cell of his/her body, since all are copied from the DNA of the original modified sperm/egg.

So now the "fossilized" viral DNA sequence will be passed on to *their* children, and their children's children, and so on. Through a process called neutral genetic drift, given enough time (it happens faster in smaller populations than large) the "fossil" viral DNA will either be flushed out of the population eventually, *or* by luck of the draw end up in every member of the population X generations down the road. It all depends on a roll of the genetic dice.

Due to the hurdles, "fossil" retroviral DNA strings (known by the technical name of "endogenous retroviruses") don't end up ubiquitous in a species very often, but it provably *does* happen. In fact, the Human DNA project has identified literally *thousands* of such fossilized "relics" of long-ago ancestral infections in the human DNA.

And several features of these DNA relics can be used to demonstrate common descent, including their *location*. The reason is that retroviruses aren't picky about where their DNA gets inserted into the host DNA. Even in an infection in a *single* individual, each infected cell has the retroviral DNA inserted into different locations than any other cell. Because the host DNA is so enormous (billions of basepairs in humans, for example), the odds of any retroviral insertion event matching the insertion location of any other insertion event are astronomically low. The only plausible mechanism by which two individuals could have retroviral DNA inserted into exactly the same location in their respective DNAs is if they inherited copies of that DNA from the same source -- a common ancestor.

Thus, shared endogenous retroviruses between, say, ape and man is almost irrefutable evidence that they descended from a common ancestor. *Unless* you want to suggest that they were created separately, and then a virus they were both susceptible to infected both a man and an ape in EXACTLY the same location in their DNAs (the odds of such a match by luck are literally on the order of 1,000,000,000,000,000,000 to 1...), *and* that the infections both happened in their gametocyte cells (combined odds on the order of 1,000,000 to 1) *and* that the one particular affected gametocyte is the one which produces the egg or sperm which is destined to produce an offspring (*HUGE* odds against), and *then* the resulting modified genome of the offspring becomes "fixed" in each respective population (1 out of population_size^squared)...

Then repeat that for *each* shared endogenous retrovirus (there are many) you'd like to claim was acquired independently and *not* from a shared ancestor...

Finally, you'd have to explain why, for say species A, B, and C, the pattern of shared same-location retroviruses is always *nested*, never *overlapped*. For example, all three will share some retroviruses, then A and B will both share several more, but if so then B *never* shares one with C that A doesn't also have (or at least remnants of).

In your "shared infection due to genetic similarities" suggestion, even leaving aside the near statistical impossibility of the infections leaving genetic "scars" in *exactly* the same locations in independent infections, one would expect to find cases of three species X, Y, and Z, where the degree of similarity was such that Y was "between" X and Z on some similarity scale, causing the same disease to befall X and Y but not Z, and another disease to affect Y and Z but not X. And yet, we don't find this in genetic markers. The markers are found in nested sequence, which is precisely what we would expect to see in cases of inheritance from common ancestry.

Here, for example, is an ancestry tree showing the pattern of shared same-location endogenous retroviruses of type HERV-K among primates:

This is just a partial list for illustration purposes -- there are many more.

Each labeled arrow on the chart shows an ERV shared in common by all the branches to the right, and *not* the branches that are "left-and-down". This is the pattern that common descent would make. And common descent is the *only* plausible explanation for it. Furthermore, similar findings tie together larger mammal groups into successively larger "superfamilies" of creatures all descended from a common ancestor.

Any presumption of independent acquisition is literally astronomically unlikely. And "God chose to put broken relics of viral infections that never actually happened into our DNA and line them up only in patterns that would provide incredibly strong evidence of common descent which hadn't actually happened" just strains credulity (not to mention would raise troubling questions about God's motives for such a misleading act).

Once again, the evidence for common descent -- as opposed to any other conceivable alternative explanation -- is clear and overwhelming.

Wait, want more? Endogenous retroviruses are just *one* type of genetic "tag" that makes perfect sense evolutionary and *no* sense under any other scenario. In addition to ERV's, there are also similar arguments for the patterns across species of Protein functional redundancies, DNA coding redundancies, shared Processed pseudogenes, shared Transposons (including *several* independent varieties, such as SINEs and LINEs), shared redundant pseudogenes, etc. etc. Here, for example, is a small map of shared SINE events among various mammal groups:

Like ERV's, any scenario which suggests that these shared DNA features were acquired separately strains the laws of probability beyond the breaking point, but they make perfect sense from an evolutionary common-descent scenario. In the above data, it is clear that the only logical conclusion is that, for example, the cetaceans, hippos, and ruminants shared a common ancestor, in which SINE events B and C entered its DNA and then was passed on to its descendants, yet this occurred after the point in time where an earlier common ancestor had given rise both to that species, and to the lineage which later became pigs.

And this pattern (giving the *same* results) is repeated over and over and over again when various kinds of molecular evidence from DNA is examined in detail.

The molecular evidence for evolution and common descent is overwhelming. The only alternative is for creationists to deny the obvious and say, "well maybe God decided to set up all DNA in *only* ways that were consistent with an evolutionary result even though He'd have a lot more options open to him, even including parts which by every measure are useless and exactly mimic copy errors, ancient infections, stutters, and other garbage inherited from nonexistent shared ancestors"...

Or how about:
Humans have 23 pairs of chromosomes ---chimps and gorillas have 24 pairs. How many pairs of chromosomes did the "common ancestor" have? Was it 23 or 24 pairs? How do you "evolve" missing or added chromosomes ---that would happen all at one time.

The common ancestor had 24 chromosomes.

If you look at the gene sequences, you'll find that Chromosome 2 in humans is pretty much just 2 shorter chimpanzee chromosomes pasted end-to-end, with perhaps a slight bit of lost overlap:

(H=Human, C=Chimpanzee, G=Gorilla, O=Orangutan)

Somewhere along the line, after humans split off from the other great apes, or during the split itself, there was an accidental fusion of two chromosomes, end-to-end. Where there used to be 24 chromosomes, now there were 23, but containing the same total genes, so other than a "repackaging", the DNA "instructions" remained the same.

If a chimpanzee gives birth to a creature with 23 chromosomes, that offspring isn't going to be a well-formed chimpanzee able to survive well.

It is if the same genes are present, which they would be in the case of a chromosome fusion.

Evolve would imply the genetic material changes little by little --not some big loss of two chromosomes at once but I don't see how they'd go away gene by gene.

Tacking two chromosomes together end-to-end is not a "big loss" of genes, and it really is a "little by little" change in the total genetic code. It's just been "regrouped" a bit. Instead of coming in 24 "packages", it's now contained in 23, but the contents are the same.

So how, you might ask, would the chromosomes from the first 23-chromosome "fused" individual match up with the 24 chromosomes from its mate when it tried to produce offspring? Very well, thanks for asking. The "top half" of the new extra-long Chromosome 2 would adhere to the original chromosome (call it "2p") from which it was formed, and likewise for the "bottom half" which would adhere to the other original shorter chromosome (call it "2q"). In the picture above, imagine the two chimp chromosomes sliding over to "match up" against the human chromosome. The chimp chromosomes would end up butting ends with each other, or slightly overlapping in a "kink", but chromosomes have overcome worse mismatches (just consider the XY pair in every human male -- the X and the Y chromosome are *very* different in shape, length, and structure, but they still pair up).

In fact, the "rubbing ends" of the matched-up chimp chromosomes, adhering to the double-long human-type chromosome, would be more likely to become fused together themselves.

For studies in which recent chromosome fusions have been discovered and found not to cause infertility, see:

Chromosomal heterozygosity and fertility in house mice (Mus musculus domesticus) from Northern Italy. Hauffe HC, Searle JB Department of Zoology, University of Oxford, Oxford OX1 3PS, United Kingdom. hauffe@novanet.it

An observed chromosome fusion: Hereditas 1998;129(2):177-80 A new centric fusion translocation in cattle: rob (13;19). Molteni L, De Giovanni-Macchi A, Succi G, Cremonesi F, Stacchezzini S, Di Meo GP, Iannuzzi L Institute of Animal Husbandry, Faculty of Agricultural Science, Milan, Italy.

J Reprod Fertil 1979 Nov;57(2):363-75 Cytogenetics and reproduction of sheep with multiple centric fusions (Robertsonian translocations). Bruere AN, Ellis PM

J Reprod Fertil Suppl 1975 Oct;(23):356-70 Cytogenetic studies of three equine hybrids. Chandley AC, Short RV, Allen WR.

In that last reference, the Przewalski horse, which has 33 chromosomes, and the domestic horse, with 32 chromosomes (due to a fusion), are able to mate and produce fertile offspring.

Meanwhile, the question may be asked, how do we know that the human Chromosome 2 is actually the result of a chromsome fusion at/since a common ancestor, and not simply a matter of "different design"?

Well, if two chromsomes accidentally merged, there should be molecular remnants of the original chromosomal structures (while a chromosome designed from scratch would have no need for such leftover "train-wreck" pieces).

Ends of chromosomes have characteristic DNA base-pair sequences called "telomeres". And there are indeed remnants of telomeres at the point of presumed fusion on human Chromosome 2 (i.e., where the two ancestral ape chromosomes merged end-to-end). If I may crib from a web page:

Telomeres in humans have been shown to consist of head to tail repeats of the bases 5'TTAGGG running toward the end of the chromosome. Furthermore, there is a characteristic pattern of the base pairs in what is called the pre-telomeric region, the region just before the telomere. When the vicinity of chromosome 2 where the fusion is expected to occur (based on comparison to chimp chromosomes 2p and 2q) is examined, we see first sequences that are characteristic of the pre-telomeric region, then a section of telomeric sequences, and then another section of pre-telomeric sequences. Furthermore, in the telomeric section, it is observed that there is a point where instead of being arranged head to tail, the telomeric repeats suddenly reverse direction - becoming (CCCTAA)3' instead of 5'(TTAGGG), and the second pre-telomeric section is also the reverse of the first telomeric section. This pattern is precisely as predicted by a telomere to telomere fusion of the chimpanzee (ancestor) 2p and 2q chromosomes, and in precisely the expected location. Note that the CCCTAA sequence is the reversed complement of TTAGGG (C pairs with G, and T pairs with A).
Another piece of evidence is that if human Chromosome 2 had formed by chromosome fusion in an ancestor instead of being designed "as is", it should have evidence of 2 centromeres (the "pinched waist" in the picture above -- chromosomes have centromeres to aid in cell division). A "designed" chromosome would need only 1 centromere. An accidentally "merged" chromosome would show evidence of the 2 centromeres from the two chromosomes it merged from (one from each). And indeed, as documented in (Avarello R, Pedicini A, Caiulo A, Zuffardi O, Fraccaro M, Evidence for an ancestral alphoid domain on the long arm of human chromosome 2. Hum Genet 1992 May;89(2):247-9), the functional centromere found on human Chromosome 2 lines up with the centromere of the chimp 2p chromosome, while there are non-functional remnants of the chimp 2q centromere at the expected location on the human chromosome.

As an aside, the next time some creationist claims that there is "no evidence" for common ancestry or evolution, keep in mind that the sort of detailed "detective story" discussed above is repeated literally COUNTLESS times in the ordinary pursuit of scientific research and examination of biological and other types of evidence. Common ancestry and evolution is confirmed in bit and little ways over and over and over again. It's not just something that a couple of whacky anti-religionists dream up out of thin air and promulgate for no reason, as the creationists would have you believe.

And:
[The poster known as Mr. LLLICHY wrote:] Here is that Vitamin C data

After discovering this same data on another thread along with more discussion than has appeared here (I've taken the liberty of pinging the participants of that discussion), I see what the "mystery" is supposed to be -- it's supposed be why did some sites have multiple mutations while (small) stretches of other sites had none? In other words, why do the mutations appear clustered?

(You know, it would really help if people explained their points and questions in more detail, instead of leaving people to guess what the poster was thinking...)

[LLLICHY wrote:] "U238" that decays thrice, pretty good trick when there is "U238" that does not decay at all in 50,000,000 years.

Actually, no site had mutations "thrice". Three different bases at a given site is only *two* mutations (one original base, plus two mutations from it to something else).

Here's the "mutation map" from the actual DNA data:

--1-12--1-1-1-1--------1112112--1---1-11-1--------1 ALL/n
No mutations ("-") in about half the sites, one mutation at several (17) sites, two mutations at three sites.

The first thing to keep in mind that random processes tend to "cluster" more than people expect anyway. People expect "randomness" to "spread out" somewhat evenly, but instead it's usually more "clumped", for statistical reasons that would be a diversion to go into right now. So "that looks uneven" isn't always a good indication that something truly is non-random.

If you don't believe me on that, I wrote a program which made 23 mutations totally at random on a 51-site sequence, then repeated the process to see what different random outcomes would look like:

10 X$=STRING$(51,"-")
20 FOR I=1 TO 23
30 J%=INT(RND*51)+1
40 C$=MID$(X$,J%,1)
50 IF C$="-" THEN MID$(X$,J%,1)="1" ELSE MID$(X$,J%,1)=CHR$(ASC(C$)+1)
60 NEXT I
70 PRINT X$
80 GOTO 10
Yeah, it's BASIC, so sue me. Here's a typical screenful of the results:
-21---1---2---111----2-----2-1121-------1---1--11-1
-1--1--21-11---1-1--1-1---1----1---21-11111---11---
3-11---3-----1-----11-2-1---1--1----3--2---1--1----
---1-1--22--1-1--2-2111--1-1111---1------1-------1-
---32----1-11-1-----1---2-231----1------1-----11--1
----2---21--1---4----1-------------11-1--111-11-211
11--1-1---1-----1--1------1----3111--1----111-2-1-2
1112---1-3-1----1-1-----1-1------121--111-------1-1
-111121--1----1----1-1-1-1-11-2---1-1-------1-111--
-----------11-1---11-11--------21----12211--1---131
--1-211-1-1----21--11-1-2----1--1----11---11-----11
12---1-13------------2---21-21---11-1-1-1--2-------
-----2-1---1-1----21--11-11-1---111-1--111-----2--1
-----1-----1-1-1-1---1-2----11-21-11--1-111---1-21-
---11--1-1-122-1-1-1--1-----2-1-1-1-------1-1---111
--2--11----2--1---12-2----1-1---1-1--1--12----1-1-1
-111-1-----1-1----------1-21111--1-2-11-11-1----11-
11-1--211-1221-----1--1-----11--1-2-1----------11--
-----1-12-11---2-1---11--1-2--1----11---111-1----11
11----1--12---12----1---31---1-11----2--1-11-1-----
---1--111-1--1-1-111----1-21----1-1-3---1------2--1
-2-11----1-1------1------2-1-1--111-111-1-1----1111
1--1--1-1---1-111111--2--1-1------112----2---11----
Notice how oddly "clustered" most of them look, including one run which left a 13-site stretch "absolutely untouched", contrary to intuition (while having *4* mutations at a single site!)

Frankly, I don't see anything in the real-life DNA mutation map which looks any different from these truly random runs. Random events tend to cluster more than people expect. That solves the "mystery" right there.

Also, there may be a selection factor -- the GLO gene is a *lot* bigger than this. One has to wonder if this small 51-bp section was presented just because it was the one that looked "least random". That would be a no-no, since one can always hand-select the most deviant subset out of larger sample in order to artificially skew the picture.

However, since there are some interesting evolutionary observations to be made, let's look at that DNA data again, slightly rearranged:

TAC CCC GTG GAG GTG CGC TTC ACT CGG GCG GAC GAC ATC CTG CTG AGC CCC  PIG
TAC CCC GTG GAG GTA CGC TTC ACT CGC GGG GAC GAC ATC CTG CTG AGC CCC  BOS

TAC CCC GTA GAG GTG CGC TTC ACC CGA GGC GAT GAC ATT CTG CTG AGC CCC  RAT
TAC CCC GTG GAG GTG CGC TTC ACC CGA GGT GAT GAC ATC CTG CTG AGC CCG  MOUSE

TAC CCT GTG GGG GTG CGC TTC ACC CGG GGG GAC GAC ATC CTG CTG AGC CCC  GUIN PIG

TAC CTG GTG GGG GTA CGC TTC ACC TGG AG* GAT GAC ATC CTA CTG AGC CCC  HUMAN
TAC CTG GTG GGG CTA CGC TTC ACC TGG AG* GAT GAC ATC CTA CTG AGC CCC  CHIMPANZEE
TAC CCG GTG GGG GTG CGC TTC ACC CAG AG* GAT GAC GTC CTA CTG AGC CCC  ORANGUTAN
TAA CCG GTG GGG GTG CGC TTC ACC CAA GG* GAT GAC ATC ATA CTG AGC CCC  MACAQUE
Here I've put spaces between codons, and clustered the closely-related species together: pig/cow as ungulates, rat/mouse for their obvious relationship, guinea pig right below them but separated because of the pseudogene nature of its GLO gene, then primates all in a group, with man's closest relative, the chimp, immediately below him, followed by the more distant orangutan, and the even more distant macaque. Also note that the top four have "working" GLO genes, and the bottom five have "broken" GLO pseudogenes.

First, let's consider just the four species with working GLO genes. Evolution predicts that even over large periods of time, these genes will be "highly conserved", with natural selection weeding out mutations that could "break" the gene. Note that the mutations will still have occurred in individuals of the population, but natural selection will "discourage" that mutation from spreading into the general population.

And before we go any further, let's talk about the "universal genetic code". In all mammals (indeed, in almost all living organisms), each triplet of DNA sites cause a particular amino acid to be formed. The mapping of triplets (called "codons") to amino acids is as follows:

Second Position of Codon
T C A G
F
i
r
s
t

P
o
s
i
t
i
o
n
T
TTT Phe [F]
TTC Phe [F]
TTA Leu [L]
TTG Leu [L]
TCT Ser [S]
TCC Ser [S]
TCA Ser [S]
TCG Ser [S]
TAT Tyr [Y]
TAC Tyr [Y]
TAA Ter [end]
TAG Ter [end]
TGT Cys [C]
TGC Cys [C]
TGA Ter [end]
TGG Trp [W]
T
C
A
G
T
h
i
r
d

P
o
s
i
t
i
o
n
C
CTT Leu [L]
CTC Leu [L]
CTA Leu [L]
CTG Leu [L]
CCT Pro [P]
CCC Pro [P]
CCA Pro [P]
CCG Pro [P]
CAT His [H]
CAC His [H]
CAA Gln [Q]
CAG Gln [Q]
CGT Arg [R]
CGC Arg [R]
CGA Arg [R]
CGG Arg [R]
T
C
A
G
A
ATT Ile [I]
ATC Ile [I]
ATA Ile [I]
ATG Met [M]
ACT Thr [T]
ACC Thr [T]
ACA Thr [T]
ACG Thr [T]
AAT Asn [N]
AAC Asn [N]
AAA Lys [K]
AAG Lys [K]
AGT Ser [S]
AGC Ser [S]
AGA Arg [R]
AGG Arg [R]
T
C
A
G
G
GTT Val [V]
GTC Val [V]
GTA Val [V]
GTG Val [V]
GCT Ala [A]
GCC Ala [A]
GCA Ala [A]
GCG Ala [A]
GAT Asp [D]
GAC Asp [D]
GAA Glu [E]
GAG Glu [E]
GGT Gly [G]
GGC Gly [G]
GGA Gly [G]
GGG Gly [G]
T
C
A
G

(The above table imported from http://psyche.uthct.edu/shaun/SBlack/geneticd.html, which also has a nice introduction to the genetic code.)

Another version of the same table with nifty Java features and DNA database lookups can be found here.

The thing which is most relevant to the following discussion is the fact that most of the genetic codes are "redundant" -- more than one codon (triplet) encodes to exactly the same amino acid. This means that even in genes which are required for the organism, certain basepair mutations make absolutely no difference if the change is from one codon which maps into amino acid X to another codon which still maps into amino acid X. (This fact allows certain kinds of evolutionary "tracers" to be "read" from the DNA, as described here).

Now back to our DNA data. The redundancy in the genetic code means that some basepair sites will have more "degrees of freedom" than others (i.e., ways in which they can mutate without disrupting the gene's biological function in any way). Let's look at the four species with working GLO genes again:

TAC CCC GTG GAG GTG CGC TTC ACT CGG GCG GAC GAC ATC CTG CTG AGC CCC  PIG
TAC CCC GTG GAG GTA CGC TTC ACT CGC GGG GAC GAC ATC CTG CTG AGC CCC  BOS
TAC CCC GTA GAG GTG CGC TTC ACC CGA GGC GAT GAC ATT CTG CTG AGC CCC  RAT
TAC CCC GTG GAG GTG CGC TTC ACC CGA GGT GAT GAC ATC CTG CTG AGC CCG  MOUSE
  T   T   T   A   T A T   T   T A T   C   C   T   T T T T T   T   T
      A   A       A   A       A   C   A           A   A   A       A
      G   C       G   G       G   G   G               C   C       C
--- --- --1 --- --1 --- --- --1 --2 -12 --1 --- --1 --- --- --- --1

Under each site of the mouse DNA, I've listed the "alternative" bases which could be be substituted for the mouse base at that site WITHOUT ALTERING THE GENE'S FUNCTION (because of genetic code redundancy). And under that I show the "mutation map" of just those four species.

Note that most of the "alternative" bases are in the third base of each codon, *and* that this is where all but one of the mutations have appeared. This is because these were the sites which were "free" to mutate in the way they did, because the mutation was genetically neutral. That doesn't mean that the first and second sites of each codon were immune from mutation, it's just that when mutations did occur at those sites, natural selection weeded them out quickly because they most likely "broke" the GLO gene for the individuals which received that mutuation. What we see above is the results after natural selection has already "filtered" the undesirable mutations and left the ones which "do no harm".

Additionally, the two sites which have mutated twice (i.e. have a "2" in the mutation map) are ones which had more "allowable" mutations. Also note that the sites which had the fewest allowable alternatives (only one alternate letter allowed) didn't have any mutations fix at those sites, which is unsurprising since a "safe" mutation would be less likely to occur there versus a site that "allowed" two or three alternatives.

All this is as predicted by evolutionary theory, you'll note.

It also explains the one anomoly of the original mutation map, which is that the mutation counts do tend to be higher at the third base of a codon.

However... What about the one exception? The pig DNA has had one mutation at a site which does not encode to exactly the same amino acid (which is the case for *all* the other ones). In the pig DNA, the GGG codon (mapping to Glycine) has changed to a GCG codon (mapping to Alanine). What's up with that? Well, one of two things. First and most likely, just as base values in codons have a built-in redundancy, so do the amino acids which make up the proteins which result from the DNA templates. In other words, certain amino acids can be substituted for other ones at some sites in given proteins without making any functional difference. (This "protein functional redundancy" also has implications for "evolutionary tracer" analysis, see here.) That may well be the case for Alanine versus Glycine in the GLO protein, but I'm not enough of a biochemist to be able to say. The other option is that it *does* make some difference in the function of the pig GLO protein, but not enough to "break" the vitamin-C synthesis (as proven by the fact that pigs *can* synthesize vitamin C). So one way or another, it's not a deal-breaker even though pig GLO will not be 100% identical to cow/mouse/rat GLO. It's yet another "allowable" mutation.

More interesting evolutionary observations: The number of mutational differences between pig/cow is 3, the number between mouse/rat is 4, and the difference between rat/cow is 7 -- all roughly as one would expect from the evolutionary relatedness of these animals (cows/pigs and rats/mice are each closer to each other than the rodents are to the ungulates).

Now let's take a close look at the guinea pig:

TAC CCT GTG GGG GTG CGC TTC ACC CGG GGG GAC GAC ATC CTG CTG AGC CCC  GUIN PIG
--- --1 --- -1- --- --- --- --- --1 --1 --1 --- --- --- --- --- ---
The "mutation map" under the guinea pig DNA is compared to the mouse DNA. Fascinating: Note that four of the five mutations are in the third base of a codon, *and* are of the type "allowed" by the genetic code redundancy. This indicates strongly that most of the evolutionary divergence between guinea pigs and mice likely occurred while the guinea pig's ancestors still had a working GLO gene. This is the sort of prediction implied by the evolutionary theory which could be cross-checked by further research of various types, and if verified, would be yet further confirmation that evolutionary theory is likely correct. So far, evolutionary theory has been subjected to literally countless tests like this, large and small, and the vast majority of results have confirmed the evolutionary prediction. This track record is hard to explain if evolution is an invalid theory, as some assert...

Finally, let's look over the primate DNA and mutation map (relative to each other):

TAC CTG GTG GGG GTA CGC TTC ACC TGG AG* GAT GAC ATC CTA CTG AGC CCC  HUMAN
TAC CTG GTG GGG CTA CGC TTC ACC TGG AG* GAT GAC ATC CTA CTG AGC CCC  CHIMPANZEE
TAC CCG GTG GGG GTG CGC TTC ACC CAG AG* GAT GAC GTC CTA CTG AGC CCC  ORANGUTAN
TAA CCG GTG GGG GTG CGC TTC ACC CAA GG* GAT GAC ATC ATA CTG AGC CCC  MACAQUE
--1 -1- --- --- 1-1 --- --- --- 111 1-- --- --- 1-- 1-- --- --- ---
Evolutionary theory predicts that because the GLO gene is "broken" in primates (i.e. is a pseudogene), mutations in it are highly likely to be neutral (i.e., make no difference, since it can't get much more broken), and thus mutations are just as likely to accumulate at any site as any other. Is that what we see? Yup. There's no obvious pattern to the mutations between primates in the above mutation map, and unlike the pig/cow/mouse/rat mutation map, the mutations aren't predominantly at the "safer" third base of a codon, nor of a type that would be "safe". In fact, one base has vanished entirely, but no biggie, the gene's already broken.

Also, although primates share a more recent common ancestor than cows/pigs/mice/rats, note that they've already racked up almost as many relative mutations as the cow/pig/mouse/rat DNA. This too is just as evolutionary theory predicts, because many mutations in a functional gene (GLO in this case) will be "non-safe" and weeded out by natural selection, making for a slower mutation fixation rate overall than in a pseudogene (as GLO is in primates) where natural selection doesn't "care" about the vast majority of mutations since *most* are neutral. So pseudogenes accumulate mutations faster than functional genes (even though rate of mutation *occurence* in both are likely the same).

Finally, note that there are ZERO mutational differences between the human DNA and the chimpanzee DNA, our nearest living relative.

I also see some interesting implications in the DNA sequences concerning which specific mutation fixed during what branch of the common-descent evolutionary tree for all the species represented, but reconstructing that would not only take another couple hours, at least, but would be a major bear to code in HTML, since I'd have to draw trees with annotations on the nodes... Bleugh.

In any case, I hope I've clarified some of the methods by which biologists find countless confirmations of evolution in DNA data. This is just a "baby" example, and to be more statistically valid would have to be done over much vaster sections of DNA sequences, but my intent was to demonstrate some of the concepts.

And if such a small amount of DNA as this can make small confirmations of evolutionary predictions, imagine the amount of confirmation from billion-basepair DNA data from each species compared across thousands of species... The amount of confirmatory discoveries for evolution from DNA analysis has already been vast, and promises to only grow in the future. For an overview of some of the different lines of evidence being studied, see The Journal of Molecular Evolution -- abstracts of all articles, current and back issues, can be browsed free online.

See also, for example (out of thousands):
Analysis of the human Alu Ye lineage

Human endogenous retrovirus HERV-K14 families: status, variants, evolution, and mobilization of other cellular sequences

Ancestral population sizes and species divergence times in the primate lineage on the basis of intron and BAC end sequences

Molecular and temporal characteristics of human retropseudogenes.

Evolution of RPS4Y

Inactivation of CMP-N-acetylneuraminic acid hydroxylase occurred prior to brain expansion during human evolution

Serine hydroxymethyltransferase pseudogene, SHMT-ps1: a unique genetic marker of the order primates

Structure and phylogenetic analysis of an endogenous retrovirus inserted into the human growth factor gene pleiotrophin

Molecular evolution of cytochrome c oxidase subunit IV: evidence for positive selection in simian primates

The ZNF75 zinc finger gene subfamily: isolation and mapping of the four members in humans and great apes

Insertions and duplications of mtDNA in the nuclear genomes of Old World monkeys and hominoids

Conservation of sequences between human and gorilla lineages: ADP-ribosyltransferase (NAD+) pseudogene 1 and neighboring retroposons

Fixation times of retroposons in the ribosomal DNA spacer of human and other primates

The gamma-globin genes and their flanking sequences in primates: findings with nucleotide sequences of capuchin monkey and tarsier

The emergence of new DNA repeats and the divergence of primates

Genetic diversity at class II DRB loci of the primate MHC

Nucleotide sequences of immunoglobulin-epsilon pseudogenes in man and apes and their phylogenetic relationships

Structure and evolution of human and African ape rDNA pseudogenes

How many more would you like?
99 posted on 03/08/2005 3:26:03 PM PST by Ichneumon
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To: TonyRo76
[Since roughly 3.8 million years ago...]

And who of us was around back then, to test and prove this theory?

Oh, puh-leaze... There are many ways to learn about past events other than just "being there to see it". This is the kind of thing taught in even gradeschool science class. How'd you miss it?

For that matter, watch any of the "CSI" TV shows that are on these days, in order to get a clue about how scientists accurately reconstruct events they didn't personally witness.

100 posted on 03/08/2005 3:29:17 PM PST by Ichneumon
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