Now that’s a stretch

| 27 Comments

The Discovery Institute’s Casey Luskin is all atwitter about a new web article from German creationist Wolf-Ekkehard Lönnig [1] about how the giraffe is some kind of massive problem for evolution. Major planks [2] include the alleged lack of transitional fossils between the different fossil giraffe genera (never mind that creationists elsewhere typically accept that the differences between mammalian genera are small, and put the “created kind” or “basic type” at a higher taxonomic level), some confusion about whether one of the giraffe vertebrae is cervical or thoracic or something in between (note to creationists: read about homeotic shifts), and the allegation that there is no evidence for a feeding advantage for tall giraffes, relying on the fact that male giraffes are taller than female giraffes and a 1996 paper in American Naturalist (Simmons & Scheepers 1996, “Winning by a Neck: Sexual Selection in the Evolution of Giraffe”) that attempted to buck conventional wisdom and suggest that sexual selection was the cause of long necks in giraffes.

Sadly, the last plank is particularly bogus, since it completely ignores and displays no knowledge of a massively relevant and quite brilliant paper, published just back in January 2007 in American Naturalist, that constitutes an experimental demonstration of the relative feeding advantage of giraffe height:

Elissa Z. Cameron and Johan T. du Toit (2007). “Winning by a Neck: Tall Giraffes Avoid Competing with Shorter Browsers.” The American Naturalist, 169, 130–135. DOI: 10.1086/509940

Abstract With their vertically elongated body form, giraffes generally feed above the level of other browsers within the savanna browsing guild, despite having access to foliage at lower levels. They ingest more leaf mass per bite when foraging high in the tree, perhaps because smaller, more selective browsers deplete shoots at lower levels or because trees differentially allocate resources to promote shoot growth in the upper canopy. We erected exclosures around individual Acacia nigrescens trees in the greater Kruger ecosystem, South Africa. After a complete growing season, we found no differences in leaf biomass per shoot across height zones in excluded trees but significant differences in control trees. We conclude that giraffes preferentially browse at high levels in the canopy to avoid competition with smaller browsers. Our findings are analogous with those from studies of grazing guilds and demonstrate that resource partitioning can be driven by competition when smaller foragers displace larger foragers from shared resources. This provides the first experimental support for the classic evolutionary hypothesis that vertical elongation of the giraffe body is an outcome of competition within the browsing ungulate guild.

The beautiful thing about this paper is how simple the experimental design is. Basically:

Step 1. Find a game reserve with giraffes in it (in this case, Lion Sands Game Reserve in South Africa, near Kruger National Park)

Step 2. Build some browser-proof 2.2 meter-high fences around some tall acacia trees (giraffes can browse up around 4 meters, for obvious reasons). Wait through two growing seasons.

Step 2.5. Fix the fences occasionally when elephants come by and smash them in a malicious attempt to spoil your research project.

Step 3. Cut off some branches at various heights and measure the amount of leafy biomass. Do the same with some unfenced control trees. Compare.

Here is one of the figures from the paper. Note: a “GBU” is a “Giraffe Browsing Unit”, an overly technical term for “giraffe bite.” So this chart is showing how much leaf biomass is available per bite for the giraffes, at 1 m, 2.5 m, and 4 m.

Cameron_du_Toit_2007_AmNat_Winning_by_a_Neck_Fig2a.jpg

Open bars are for the fenced trees, black bars for the unfenced control trees. You can see that the unfenced trees are severely denuded of leafy biomass at the low elevations, being heavily browsed by numerous critters. Giraffes, on the other hand, avoid this competition. Conclusion:

Despite popular acceptance that giraffes have long necks because of foraging competition during their evolution, no previous studies have experimentally investigated foraging competition between giraffes and smaller browsers. Simmons and Scheepers (1996) argued that there was little evidence that giraffes forage high in the canopy because of competition and suggested sexual selection as an alternate hypothesis. However, Woolnough and du Toit (2001) showed that giraffes achieve a bite-size advantage by feeding higher in the tree, and now we show that this is explained by the avoidance of competition with smaller browsers. While not resolving the controversy, our study provides the first experimental evidence that the giraffe’s extremely elongated body form is naturally selected in response to competition from smaller browsing species.

As the paper notes, this has always seemed pretty “obvious” to most people – especially if you have been to Africa and seen all the large herbivores, browsers and grazers of different shapes and sizes, living on one landscape by dividing up the food resource in minute ways (in fact, I noted that it was pretty obvious back in this 2005 PT post). But sometimes it’s nice to experimentally test the obvious – especially when creationists are going around denying it.

Notes

[1] Yep, he’s apparently pretty clearly a traditional creationist of the Jehovah’s Witness variety. He appeared in the German video Is the Bible Right After all? The theory of evolution lacks evidence. See links 1, 2, 3, 4.

[2] Amongst a large about of debris in the form of creationist ranting-n-raving about unrelated issues.

27 Comments

Step 2.5. Fix the fences occasionally when elephants come by and smash them in a malicious attempt to spoil your research project.”

Now I understand the ‘Elephants’ line item in the Discovery Institute budget. I’d thought it might be code for Republican Party donations or somesuch …

Let me see if I understand the logic here…

A YEC guy makes some typical false statements claiming that scientists know less about giraffe evolution than is actually the case.

He doesn’t necessarily say what his explanation for giraffe morphology is, but to his marginal credit, if he’s YEC, we all know what it must be - God magically created giraffes in their current form, or created something very close, about 6000 years ago, then a couple of thousand years after that, all giraffes except the two that Noah took on the ark were killed in a flood, then giraffes disembarked the ark in Turkey after 40 days at sea, and that’s how we got modern giraffes in Africa.

And the reason YEC is less crappy crap than ID is that this is a testable hypothesis. In fact, it’s been tested - and proven false.

Okay, what’s the testable ID explanation for the morphology of modern giraffes? How does a false understatement of scientific progress by a YEC creationist have anything to do with ID?

Lönnig claims to be doing ID in this paper, and gets indignant if someone suggests that ID is creationism. He might or might not be YEC himself, I don’t know of any evidence either way (he does refer to millions of years in this giraffe paper, but that is not necessarily definitive).

How shocking. In other news, it was announced today that “ID” is no longer an acronym for “intelligent design,” since that was an immature scientific theory. It is now understood to stand for “incessant dishonesty.” In a closely related move, the Discovery Institute will be changing its name to Kentucky Fried Crapola and opening a service counter at a certain new museum, right next to the exhibit that explains how T. rex ate coconuts.

harold Wrote:

Okay, what’s the testable ID explanation for the morphology of modern giraffes?

Goddidit. Testable by waiting until you die, then asking him for confirmation.

This is at the conclusion of Loennig’s paper:

13. Acknowledgements

I would like to thank Professor Granville Sewell, Mathematics Department of the University of Texas El Paso for the English translation of Part 2 of this giraffe paper. Mr. Roland Slowik prepared the figure showing the simultaneity of the genera. Dr. Wolfgang Engelhardt (physicist, Munich) gave me the German translation of the book of G. R. Taylor The Great Evolutionary Mystery as a present. Last (and of course) not least, I thank the One without whom there would be no giraffes (Revelation 4:11).

A good place to see the general flaws in JW creationism is here and in other online writings by Alan M. Feuerbacher

http://www.talkorigins.org/faqs/jw-evolution.html

A J-dub that openly believes in intelligent design? Does that mean he accepts common decent? If so they have moderated quite a bit since they kicked me out for disagreement on that and other issues (such as a global flood), but then that was 5 years ago.

You will find quite some information on Lönnig’s claims and the Max-Planck-scandal at evolutionsbiologen.de. Unfortunately, in German only.

Nick Matzke Wrote:

Lönnig claims to be doing ID in this paper, and gets indignant if someone suggests that ID is creationism. He might or might not be YEC himself, I don’t know of any evidence either way (he does refer to millions of years in this giraffe paper, but that is not necessarily definitive).

As an IDer who “gets indignant if someone suggests that ID is creationism,” he probably has few fans among YEC leaders, if that’s what you mean. Unless his “millions of years” is framed specifically only as something “Darwinists” claim, it’s a safe bet that he has no problem if the reader infers OEC. If that’s the case, it’s a safe bet that he personally thinks that YEC is nonsense, but of course would not admit it.

Bob King:

A quote from the link you posted:

“Note particularly that Life selected a 1976 version Encyclopedia Britannica to support its position, because the 1983-84 versions did not say what Life’s author wanted. Life was published in 1985.”

Can someone please tell me why nearly everyone assumes that these people personally believe the nonsense that they peddle? Yes, I know about Morton’s Demon, but can we at least admit that we have no basis to assume that it’s operating in every single case.

sparc. can you give me a rundown of the MPI scandal? I’m starting a PhD at one of the Max Planck Institutes in a few months and just wanted to know what it was about.

JohnW

harold wrote:

Okay, what’s the testable ID explanation for the morphology of modern giraffes?

Goddidit. Testable by waiting until you die, then asking him for confirmation.

Sounds good. Of course, then, there’s the difficulty in finding a journal in which to publish the results…

What is the evolutionary relationship between okapis and giraffes ? Aren’t okapis some kind of midget giraffes ?

In other words, wouldn’t an okapi skeleton, or an okapi fossil demonstrate that there are transitionals to the giraffe ?

molecanthro,

you will find a short description of the affair by Ulrich Kutschera at http://www.uni-kassel.de/fb19/plant[…]y/abbott.pdf.

There wouldn’t be anything new about males and females partitioning a niche, presumably in order to reduce competition. This appears to have happened in various species, with an example in the following link:

http://www.blackwell-synergy.com/do[…]2004.00377.x

Of course we don’t know why males are taller than the females, perhaps it is indeed because of sexual competition. Taller and larger are both generally better for sexual competition, regardless of their selective adaptations to an environment.

My point about the possibility of niche partitioning is primarily that one ought not to automatically assume the reasonable sexual competition hypothesis, even when it’s certain that both sexes of giraffe have a feeding advantage. Niche partitioning and sexual selection could both be working to make the taller males, to state the obvious.

The Simmons & Scheepers hypothesis manages not to explain the length of the female’s necks, except as a kind of side effect. The latter might be reasonable enough, I suppose, if the costs of such height weren’t substantial without a corresponding greater access to resources, or other advantage(s).

In all of these hypotheses, however, I wonder why the advantage of height in seeing predators isn’t mentioned more often. I doubt that it could be the major force for selection, but as a selective advantage in a kind of “supporting role” I would think it could have an effect (probably difficult to distinguish from more important selective pressure, however).

Glen D

My point about the possibility of niche partitioning is primarily that one ought not to automatically assume the reasonable sexual competition hypothesis, even when it’s certain that both sexes of giraffe have a feeding advantage. Niche partitioning and sexual selection could both be working to make the taller males, to state the obvious.

This is very, very true. I also think that the feeding of young giraffes should be taken into account. Probably even a recently-weaned giraffe is 2+ meters tall and already above most of the competition, this may be as important as anything.

In all of these hypotheses, however, I wonder why the advantage of height in seeing predators isn’t mentioned more often. I doubt that it could be the major force for selection, but as a selective advantage in a kind of “supporting role” I would think it could have an effect (probably difficult to distinguish from more important selective pressure, however).

It’s not clear to me that this idea works. First, why giraffes and not other things? (with niche partitioning, you have an explanation of why there should be a bunch of slots that different species fit into). Second, adult giraffes are so huge (they are not just tall, they are *huge*), I don’t think they get serious predation except maybe as babies. Third, it’s not self-evident that height provides a predator-sighting advantage in the kind of forest/scrub environment where giraffes live. It might on a grassland, but then giraffes aren’t primarily on the open grasslands.

The place where you do see a predator-sighting adaptation is in horses, zebras, wildebeest, etc., which IIRC have their eyes on the side and far back on the skull, so that when their nose is in the grass they can still see quite a distance for almost 180 degrees.

It’s perfectly possible that multiple factors could interact to amplify selection for extremely long necks.

Pure sexual selection usually refers to a case where the exaggerated trait is disadvantageous except in the context of attracting mates.

However, female preference for longer-necked males (or vice versa) and adaptation to exploiting higher vegetation are not mutually exclusive.

The patas monkey, one of the few monkey species that spends a substantial amount of time in a savannah-grasslands environment, displays an upright “lookout” or guard stance.

It’s said that the principal lookout is typically the highest-status male in the group, though it’s unclear–in brieg googling of the topic–how much this is based on observations of captive social groups as opposed to investigations in the wild.

But ethologists have been aware of the upright behavior for some time–I can remember my college professor in my anthro “Primate Cultural Behavioral” course, Dr. Suzanne Chevalier-Skolnikoff, discussing this back in the late ’60s, early ’70s.

This upright predator-location behavior has, of course, stimulated obvious speculation as to the advantages of the upright stance in another primate lineage.

Though I tend to agree with Nick that giraffe height is more likely due to feeding than predator-defense behavior.

To put in my two cents - if there’s several advantages to having a longer neck, it’s apt to be quite difficult to verify the relative importance of the various effects, and it certainly isn’t an “either/or” situation.

Henry

molecanthro, one thing I forgot: During my PhD work I was two years at the Max-Planck-Institute for Biochemistry in Martinsried and I can assure you that Lönnig is the big exeption. Indeed, working there was really fun: open-minded collegues, quite some freedom to try your own science, best equipment, best funding, good seminars, lean administration etc. The only disadvantge: You will not be prepared for the reality at universities where you have to cope with old equipment, lack of money, teaching and a giant administrative overhead.

sparc,

thanks for that. yeah, i’m very excited about moving over to leipzig. i’ll be at the MPI for evolutionary anthropology and it seems like an incredible place with loads of funding and great people. and i’ve heard that the main problem is that people that come out of there aren’t prepared for ‘the real world.’

i’m glad to hear that lonnig’s institute is the exception. i’m surprised that they let that nonsense stay on the MPI website for so long. perhaps it’s because the creationist threat hasn’t been so bad in germany like it has been in the US and is becoming in the UK.

Is it also possible that the co-evolution mechanism is operating in addition to the others you have all mentioned? When the process started there were many low tier browsers so there was pressure on the plants to grow taller. That created the pressure for a tall browser. Then the giraffe’s predecessors won the battle for the tall browser niche and the race between the plants and the giraffes was on, sealing the fate of the giraffes.

Sincerely, Paul

I just about forgot about this thread, but just noticed Dr. Matzke’s thoughtful comments.

There doesn’t seem to be a lot of hard data on giraffe predation, but it didn’t take very long on a search engine to find a source that suggests that giraffe predation isn’t uncommon:

Lions kill a lot more giraffes than was formerly assumed. In Nairobi National Park, for instance, no less than ten were brought down from January 1965 to May 1967, nine of them adults and one very young. A good number of victims have been recorded since then, and I have also seen giraffe kills on Mount Marsabit and in the Samburu and Amboseli reserves. With the element of surprise on its side, a lion does not seem to have any great difficulty in toppling over even the biggest giraffe. Audrey Moore, wife of former Serengeti game warden Monty Moore, reports that males, who like to do things the easy way, quite often attack giraffes because they are such easy prey. Alerted in time, however, the huge ungulates are capable of putting up an effective defence, hitting at the attackers with chopping downward blows of their forelegs. I have seen giraffes look down on lions only 15 (50 ft) to 20 m (66 ft) away, obviously quite confident that they would be capable of dealing with any hostile intentions.

http://www.carnivoraforum.com/index[…]2#1166618087

Anyhow, it has great pictures of lions with a giraffe that they’re eating, though it’s unclear to me how it died (perhaps it’s explained in other posts). From what I’ve read, giraffes are actually fairly smelly (even though I don’t recall this from zoo visits), due to some anti-bacterial substance in their fur, so it looks as if lions aren’t especially relying on their olfactory senses in those pictures.

The size of giraffes might have seemed more important to me before I saw lions attacking an elephant on some nature show (no, it wasn’t a baby, though it may not have been full grown), supposedly successfully.

First, why giraffes and not other things? (with niche partitioning, you have an explanation of why there should be a bunch of slots that different species fit into).

Actually, I believe it does happen with other things, like with ostriches and emus. Humans are thought to have benefited from a better view of potential predators by becoming upright as well. But then I never supposed it was the primary cause (in either mammal’s case, in fact, though I didn’t write about humans), as I wrote here:

Davidson Wrote:

I doubt that it could be the major force for selection, but as a selective advantage in a kind of “supporting role” I would think it could have an effect (probably difficult to distinguish from more important selective pressure, however).

Nick Matzke Wrote:

Second, adult giraffes are so huge (they are not just tall, they are *huge*), I don’t think they get serious predation except maybe as babies.

However, this would not detract from the value of seeing from a height in females with young, even if it were the case that predation was mainly upon the young (the linked source suggests that it is not so).

Third, it’s not self-evident that height provides a predator-sighting advantage in the kind of forest/scrub environment where giraffes live. It might on a grassland, but then giraffes aren’t primarily on the open grasslands.

As one who has never been to Africa, it would be difficult for me say much definitively on this subject. However, just going from what I’ve seen on TV, etc., the acacia groves that they feed on seem to be separated by considerable distances (not blocking much of the view), and the scrub looks like it might be especially advantageous to be very tall to see over, or at least through the thinner growth at the tops of bushes, etc. An ostrich’s (wildebeest’s, zebra’s, human’s) height might be reasonably good for seeing on the open savanna, while seeing well over scrub might require a greater height.

In the pictures on TV and elsewhere, I see the giraffe’s towering over everything except the acacias. I know that these pictures are selected so that we can see the giraffes, nevertheless I don’t see much around the giraffes that would block them, except for the sparse tree growth (and that’s a partial block, in most cases).

In any case, as I indicated, I would not suppose that the costs of the giraffe’s height would be covered solely by better viewing of predators. I just think that it would be of value, just as it is believed to be one source of selection for human uprightness (there, too, it does not seem obvious as the primary cause. I believe that being able to stay cooler is today considered a stronger force in the evolution of uprightness).

Anyway, it’s been fun actually discussing the matter for once, whatever the merits of what I wrote may be.

Glen D

Just an excerpt from The Riddled Chain on giraffe evolution:

One might think that it would have been fairly easy to acquire a longer neck. Or so it would appear from the fossil record of their bones. There is no need for additional cervical (neck) vertebrae, for giraffe have seven vertebrae in their necks just like us; they just needed to extend the segments they had. But it was not quite so easy. Earlier in this chapter I discussed some of the circulatory problems we have as upright bipeds. But getting blood to flow through the tallest creature on earth is a particularly difficult biological problem. Life at the top is not easy.

One of my colleagues back at the University of the Witwatersrand, Graham Mitchell of the Physiology Department, studied giraffe circulation as well as other aspects of their unique biology. He explained the many difficulties encountered by the long-necked giraffe. The most obvious problem is getting blood to the head, about 2 meters above the heart. A simple stretching of the neck was not enough, for blood vessels must have strictly controlled constriction to force the blood up to the brain. But just the opposite is the case when the giraffe awkwardly reaches its head down to drink water; suddenly there is immense gravitational pressure forcing blood to the head, and a unique network of vessels had to evolve to redistribute the pressure, thus avoiding a massive accumulation of blood or rupturing of the vessels. The system is well enough specialized, both anatomically and physiologically, that when the giraffe has satiated its thirst and quickly lifts its head to its loft heights, it does not faint. You or I could probably not withstand such pressure changes without ill effect.

The giraffe not only has to adapt to an environment, but to itself. Its large size requires elaborate modifications of the usual mammalian circulatory system, both above and below the heart, to accommodate the gravitational pressures. Just imagine the varicose veins you would have if you simply expanded to giraffe size; I do not wish to fathom the hemorrhoids.

Large animals also have to deal with new problems of thermoregulation: there is a much larger mass inside the body, and a proper temperature must be maintained, especially in the sensitive brain. Graham Mitchell has also studied giraffe thermoregulation, and found that the highly evolved nasal apparatus and blood vessel networks work together to cool the brain. But the brain is a long way from the rest of the body in such creatures, and the African savannah sun can get very hot. One of the solutions for the giraffe is its spots, or dark patches. It is normally thought that the patchy coloring of the giraffe is meant for a degree of camouflage, and indeed I often marvel at how I can stare across the African landscape for a considerable time before my eyes focus on a previously unnoticed giraffe. But underneath the dark patches is a rich network of blood vessels that can be physiologically infused with blood to release heat to the surface, as required. Even Lamarck could not have thought of such a clever solution, had he needed to.

[snip]

Environmental change does indeed have effect some on animals. Either their adaptations allow them to survive under the conditions in which they try to live, or they die and go extinct. The short-necked Sivatherium maurusium, like Australopithecus robustus and millions of other extinct species, are proof enough that animals do not always adapt, or that their ‘adaptations’ were fleeting. Extinction is an all-too-real option as they succumb to the ox-bow lake effect. Likewise, our scars of human evolution are mere reminders of the same principle: you can’t always get what you want. Adaptation comes when chance and chaos allow it, not necessarily when it is needed.

Giraffe biology, remarkable though it is, is not perfect either. There would probably be more of them if it were perfect. Our giraffe expert, Graham Mitchell, brought this to my attention in a way which I initially thought showed his naïveté as regards evolutionary theory. This took the form of two questions. He first asked why, if eating from the tops of trees was such a grand adaptation, are the young incapable of reaching such a food source? His question is easily answered in terms of the benefit to the species if adults in their reproductive years have an adequate food source; after all, it is the adults who must survive to produce the young. (Young giraffe, like other browsing mammals, must compete for the food lower down until they reach greater heights.) On the other hand, Professor Mitchell’s point was well taken, for it had some punch: mortality among giraffe in their first year has been documented to range up to 73%. Obviously, the youth are not faring well. The giraffe biological system is so finely tuned that variants from the theme may prove to be fatal. The same may be true of humans and other mammals!

Professor Mitchell’s second question concerned why the giraffe did not evolve long necks earlier, in the more distant past. This point smacked of the same ignorant notions of Darwinian theory with which I started this chapter. A giraffe cannot get a long neck at will any more than a snake can start eating grass or a bird can start to photosynthesize. Mitchell’s own answer, however, was very Darwinian and not in the least Lamarckian. The reason was not of environmental forcing, as Lamarck would have had it, but of opportunity. Before a giraffe could evolve a long neck, which could have given it an advantage even before the reduction of the African woodlands, it had to have in place the physiological mechanisms to allow it to adapt to itself. At least it had to have the potential to compensate for its changes in size and shape. As a non-linear dynamic system, its own body determined its evolutionary potential.

Giraffids and hominids were evolving in very different ways to the same environmental circumstances: the cooling and drying of Africa. Their biological solutions were very different, and had different ways of dealing with the intrinsic consequences of blood circulation. In some ways the giraffe was more successful in the acquisition of innovative designs to overcome gravity. In other ways we can be proud of our own distinguished biological heritage, using those large brains on top of our shoulders. Neither solution is perfect. Both solutions were opportunistic accumulations of features that permitted one to survive one’s environment as well as oneself, and among the chaos of competing bodily functions, each hit upon a different morphological attractor. In both cases, the evolution of one part of the body led to potentials for evolution of another.

(I just fixed this one, your [snip] in angular brackets messed it up – Nick)

As one who has never been to Africa, it would be difficult for me say much definitively on this subject. However, just going from what I’ve seen on TV, etc., the acacia groves that they feed on seem to be separated by considerable distances (not blocking much of the view), and the scrub looks like it might be especially advantageous to be very tall to see over, or at least through the thinner growth at the tops of bushes, etc. An ostrich’s (wildebeest’s, zebra’s, human’s) height might be reasonably good for seeing on the open savanna, while seeing well over scrub might require a greater height.

In the pictures on TV and elsewhere, I see the giraffe’s towering over everything except the acacias. I know that these pictures are selected so that we can see the giraffes, nevertheless I don’t see much around the giraffes that would block them, except for the sparse tree growth (and that’s a partial block, in most cases).

In any case, as I indicated, I would not suppose that the costs of the giraffe’s height would be covered solely by better viewing of predators. I just think that it would be of value, just as it is believed to be one source of selection for human uprightness (there, too, it does not seem obvious as the primary cause. I believe that being able to stay cooler is today considered a stronger force in the evolution of uprightness).

I think this is an argument for “better sighting of predators” being an exaptation rather than an adaptation. One also should consider other factors. Big tall critters are a lot easier for the predators to see also. Being big and tall has a lot of physiological costs, etc. So if you want to explain *why* giraffes got tall you’ve got to look for whatever key factors overrode the costs which would otherwise block that adaptation.

As for tree density where giraffes live, I don’t really know of course, all I can say is the places I’ve seen giraffes tended to be “open woodland”-type areas with fairly limited visibility especially if your head is up in the canopy.

On an unrelated issue:

I keep mentioning the bigness vs. size issue. The whole creationist argument about fossil giraffes being “short” is total bogosity. Most of the fossil giraffes were already huge, way bigger than almost any antelope. E.g. Palaeotragus germaini was 3 meters tall even with a “short” neck. So the legs and neck may have lengthened by maybe 50-100%. This is quite impressive but it is not the kind of extreme change that creationists and sometimes others seem to have in their heads.

“(note to creationists: read about homoerotic shifts), “

Christ now that would make their heads explode.…

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This page contains a single entry by Nick Matzke published on May 10, 2007 4:06 PM.

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