Giraffes: The next Icon of IDiocy

29 03 2007

There are few animals as utterly charming as the giraffe, but the question of just how it got its neck (and internal systems to support such an adaptation) has been a vexing one. I’ve been planning to write something on giraffe evolution for some time now, but I didn’t have the impetus to do so until I popped over to UD today and saw Dembski had posted a screed proclaiming that the question of how the giraffe got its next must lead us to “alternatives” to evolution. The article is wrong from the onset, and (as seems to nearly always be the case) Stephen Jay Gould already addressed this issue years ago.

Unfortunately, I returned Gould’s collection of essays Leonardo’s Moutain of Clams and the Diet of Worms to the library so I can’t quote directly from the article, but in the latter part of the book there is an essay dealing specifically with giraffes. As Gould correctly notes, many have used giraffes as a symbol of false Lamarckian evolutionary principles, the classic textbook treatment stating that Lamarck thought over generations the giraffe stretched its neck further and further to reach delicious leaves, thus passing on this trait to its offspring, but this treatment is far from accurate. The book Tall Blondes chronicles how the giraffe was (and even still is) an enigma while other creatures become more well-known, and thus few scientists gave it detailed treatments in their writings or used it as an example; too little was known about giraffes to make such a tactic prudent. From what I remember of the Gould essay, Lamarck only mentioned the giraffe in passing and Darwin initially referred to it not about its neck, but about the use of its tail as a flyswatter. Indeed, giraffes tails are so wonderful as flyswatters that at times they were hunted for their tails, which made traditional wedding gifts, and Darwin considered how such an anti-pest adaptation may allow animals like giraffes to inhabit more infested landscapes. Again, if I remember correctly, Darwin did discuss the giraffe in more detail in later writings, but primarily in response to criticisms from another scientists and not as a triumphant proof of evolution.

The short preview suggests that evolutionists either have to figure out exactly how the giraffe got its neck and other essential internal organs (sounds like the flagellum argument all over again) or embrace saltation, which would certainly not work given the necessity for integrated systems to be in place to allow the giraffes head to be up so high. Thus, the writer procliams, the intelligent design “alternative” wins out, and I would not be surprised if the giraffes neck was the next attempted “Icon of IDiocy”. For my own part, I’ve still got plenty of reading to do on extinct and extant giraffes, but hopefully soon I’ll have something more substantial here for you all.


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6 responses

29 03 2007
Chris Harrison

I thought Dembski had a PhD? I know the guy’s committed to overthrowing Darwinism (whatever that is) by any and all means–integrity be damned–but is he really this dumb?
What a sad little man. I wish he didn’t live so close to me.

Anyway, on to giraffe evolution. We’ve all heard the standard explanation about longer-necked individuals having an advantage since they could reach the higher leaves, which is a typical and perfectly plausible example of natural selection.
Another idea would be that of sexual selection. Male giraffes fight each other and their primary weapon is their necks. Darren Naish has a post talking more about this and why the original explanation (taller=more food) seems most plausible. http://scienceblogs.com/tetrapodzoology/2007/02/dammit_and_i_sooo_loved_the_ne.php

29 03 2007
laelaps

Hi Chris. I’ll check out Darren’s post you mentioned; I also found some of the original papers dealing with the sexual selection hypothesis as well. In order to answer this question, I think we’re going to need to look at behavior and ecology as well as morphology; just looking at the giraffe’s neck in its current state and trying to go backwards morphologically isn’t likely to result in the right answer.

I actually was a little disappointed when I learned of the sexual selection idea; I had just developed it myself (before doing any extra reading) and had a eureka moment only to find it had already been brought up (ditto for punctuated equilibrium a few years ago, rats). I also must wonder about animals like the gerenuk; while not as tall or “magnificent” as the giraffe, they too have long necks and long legs, and can stand up to reach higher foliage when necessary. Indeed, perhaps the giraffe’s neck didn’t develop to reach higher foliage, but rather to reach a greater swath of foligae, being that they are not always eating from the top branches. Granted, they can reach where others can, but giraffes can be observed eating from shoulder height, stomach, height, etc., and the evolution of long legs likely went along with this to provide balance (can you imagine an animal with a neck that long with short legs?).

In any case I doubt that I’ll be able to solve the puzzle, but I don’t think there’s any one answer to the question; perhaps it was a sexually selected feature (females like some crazy things) that had a direct advantage to browsing at various heights, and the two together spurred evolution. I also have to wonder if development played any role, although this would be the “holy grail” macromutation that wouldn’t make sense being the systems of the animal would have to be integrated in order to work (hence just-so developmental changes to the heart, legs, etc. simultaneously).

Anyway, before I get ahead of myself (or make an ass of myself) I should probably stop. Like I said I doubt that I’m going to solve the puzzle, but in order to solve it we’re going to have to consider paleontology, behavior, ecology, behavior and feeding patterns of other herbivores, botany, etc. to look at the “big picture.” One of the major pitfalls of evolutionary theory is the ability to seize upon one feature and block everything else out, whereas I believe we can’t hope to understand how the giraffe “got its neck” without considering the setting in which such a change was taking place.

29 03 2007
Chris Harrison

Yes, I don’t think there is one answer to such a drastic morphological change, no doubt there were many contributing factors. Some of your queries will be cleared up once you read Darren’s post, but it is obvious that other animals have similar solutions (the gerenuk) and that this is not incredibly unlikely adaptation. Whatever the selective pressures, they must have been rather strong, considering what giraffes traded for their long legs and necks. Have you ever seen one drinking from a lake? They virtually have to do the splits to reach the water. And of course a newborn giraffe’s first experience outside of the womb is a 6 foot plummet to the ground. Awkward but amazing creatures.

2 02 2008
Fine Tuning on the Radio | Tangled Up in Blue Guy

[…] ran the Gish Gallop again, throwing in giraffe necks and human birthing as if they were somehow miraculous when they are obvious adaptations from prior […]

8 10 2009
Phoenix

Brilliant article! Thank you very much!!

21 10 2012
Bizarrices da vida lamarckiana - Uma Malla Pelo Mundo

[…] Não caia também na falácia de que girafas são “exemplos da necessidade de alternativas à evolução”. O post supra-citado do Laelaps informa como a evolução darwiniana da girafa aconteceu – […]

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