Woodpecker's tongue
James K Nelson
http://www.answersingenesis.org/creation/v18n1/tongue.htm
What does anyone know about this? Any experts in Woodpecker anatomy?
I see that this is in the request for FAQs, but I've never seen this
particular example. I'm sorry if the regulars have been through this; I
have not.
In essence, it's just an Argument from Personal Incredulity ("I don't
see how it could have evolved!"), but I know that many seemingly
convincing examples can be easily demystified by someone knowledgable
with the specifics of the example and with related animals.
-JKN
Tim DeLaney
Well, I'm not, but we have a resident expert on woodpecker anatomy. His
name is Karl Crawford, and if my guess is correct he will any moment now
post his regurgi ... err ... essay on the significance of woodpecker
anatomy to evolution.
And it will be all your fault.
--
Tim DeLaney
"I often say that when you can measure what you are speaking
about, and express it in numbers, you know something about
it; but when you cannot express it in numbers, your knowledge
is of a meagre and unsatisfactory kind ...
--- Lord Kelvin
Rev Chuck
Tim DeLaney wrote:
> [...]
>
> Well, I'm not, but we have a resident expert on woodpecker anatomy. His
> name is Karl Crawford, and if my guess is correct he will any moment now
> post his regurgi ... err ... essay on the significance of woodpecker
> anatomy to evolution.
>
> And it will be all your fault.
>
> --
He reposts it very six to eight months on average. Within a week, it's
refuted, burned, buried. By this time, Karl's gone back into hiding.
When the time comes, when he thinks all is forgotten, he's back with
his Karlpecker theories once more.
Stephen Watson
The web site contains an article by one David Juhasz, which appears to
be the same as one of the "references" given in Karl's standard
regurgipost. I'll save Karl (and everyone else) the trouble. Here,
from my archives, is 1) a response to Karl's woodpecker regurgipost by
Chris Brochu and 2) Karl's absolutely devastating rebuttal:
1)================================================================
From ga...@mail.utexas.edu Thu Jul 11 16:14:04 EDT 1996
Article: 143390 of talk.origins
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From: ga...@mail.utexas.edu (chris brochu)
Newsgroups: talk.origins
Subject: Re: question for ksjj
Date: 11 Jul 1996 01:06:33 GMT
Organization: University of Texas at Austin
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In article <ksjj-10079...@abe-ppp316.fast.net>, ks...@fast.net (ksjj) says:
>
>
>Poor tactics. to bad your research lacks.
>
Toward the end of your post, you list encyclopedias as your references.
I thus decided to try two other sources - the primary literature and
the woodpeckers themselves.
After drilling a hole in a tree
>the woodpecker sticks his long tongue into the tunnels and then secretes
>a sticky substance from special tongue glands.
These "special tongue glands" are salivary glands. All tetrapods have them.
Nothing special here, except that the saliva is a bit stickier.
The woodpeckers tongue is so long that he
>has to put it somewhere. God in His creation wisdom had a solution,
>attach it to his right nostril. The woodpecker tongue splits in two,
>like a Y, exits through a hole in the back of the beak. Each half then
>goes under the skin on separate sides, up and around the back of his
>head, where it is joined together as it passes over his forehead area,
>then into the right nostril where it attaches.
The first place I checked was Pough et al.'s Vertebrate Life (3rd Ed.) Not
exactly primary literature, I know, but it was a starting point.
on P. 628:
"The tongue of the green woodpecker, which extracts ants from their tunnels
in the ground, extends four times the length of its beak. The hyoid bones
that support the tongue are elongated and housed in a sheath of muscles
that passes around the outside of the skull and rests in the nasal cavity."
Note: (1) Nothing about the tongue attaching to the nostril; (2) Specific
references to the hyoid, not the tongue, extending around the head. This
reference also includes a picture of a woodpecker tongue, and guess
what! - it doesn't fork or split at all! The hyoid bone, on the other
hand, splits quite deeply. This may sound amazing until you realize that
all advanced tetrapod hyoids split in some way.
This reference also points out that hummingbird hyoids are very similar
to woodpecker hyoids; woodpeckers are thus not as unique as first thought.
Still, this wasn't a primary reference, so I looked further.
G.M. Allen's Birds and their Attributes, p. 85:
"In some species they are of great length, slender and pointed, with
horny barbs at the tip, but none at the base." Note - nothing about
splitting.
"The tongue-bones or hyoids that support the tongue are so long that
instead of being attached at the back of the skull as in most birds, they
are in certain woodpeckers forced to curl over the top of the head and
actually pass over the forehead, coming together at the top, and out
under one nostril into the tip of the beak."
Please note - NOTHING about the tongue actually attaching to the nostril.
Allen specifically states that the HYOID, h-y-o-i-d, is the most
modified element.
Allen also points out that the extent of the hyoid varies from one woodpecker
to the next.
I would actually argue with Allen on one point - the hyoids actually don't
"attach" to the back of the skull in most birds, but instead have the
corpus (central element) rest against part of the pterygoids.
Although they don't specifically discuss woodpeckers, George and Berger's
Avian Myology has some excellent pictures of bird pharynxes and hyoid
regions, showing that in most or all, the hyoid maintains a pair of back-
projecting processes surrounded by muscles. The woodpecker hyoid owes its
magnificence to an extreme elongation of these posterior processes.
I was still confused about something - what, specifically, did these authors
mean by "out under one nostril" and the like? Unfortunately, the
illustrations weren't clear enough on that point. So, I went to the
ultimate "primary reference" - some dead woodpeckers. In particular, I
looked at skeletons of Melanerpes erythrocephalus (red-headed woodpecker)
and M. carolinus (red-bellied woodpecker) in the vertebrate paleo lab
here. The red-belly was particularly good because the preparator took
great care to preserve the tongue itself, which absolutely, positively
does not fork, and absolutely, positively does not attach to the nostril.
Basically, the posterior projections (ceratobranchial/epibranchial elements)
pass back (as they do in all birds), and then over the head. They have to
go somewhere, so they pass into the nostril. They don't actually attach to
the nostril - just pass through it. That's all.
THe extent to which an animal can project its tongue is related (in part)
to the mobility of the hyoid. The extreme length of the cerato/epi elements
gives the whole hyoid much more "reach."
My references (in no particular order):
Pough, F.H., J.B. Heiser, and W.N. McFarland, 1989. Vertebrate Life
(3rd ed.). MacMillan, New York.
Allen, G.M. 1925. Birds and their Attributes. Marshall Jones,
Francestown, NH.
George, J.C., and A.J. Berger. 1966. Avian Myology. Academic Press,
New York.
Q. what is the
>evolutionary mechanism that allowed the tongue to take such a unique and
>complex path from the beak to the nostril?
Since it doesn't do what you say it does, this is nonsequitur. On the
other hand, the hyoid does some very interesting things. One possible
mechanism is enlargement of the tongue, which can epigenetically lead
to an enlarged base (hyoid).
What good was it when it was
>not complete and fully functional?
It was complete and functional all along. Indeed, the actual size
and extent of the hyoid varies among living woodpeckers.
Furthermore, there is an assemblage of fossil woodpeckers from the Eocene
of Germany (Grube Messel) that might shed some light on early piciform
morphology; from what I understand, they're still under study.
Also, some Eocene fossils have been classified as woodpeckers, but closer
examination makes the identifications much less certain, and some may
be closer to rollers. "Intermediate forms" therefore exist in museum
collections.
chris
2)========================================================
And Karl's response:
From: ks...@fast.net (ksjj)
Message-ID: <ksjj-11079...@abe-ppp364.fast.net>
References: <4rul1m$5...@geraldo.cc.utexas.edu> <ksjj-10079...@abe-ppp316.fast.net> <4s1k2p$8...@geraldo.cc.utexas.edu>
In article <4s1k2p$8...@geraldo.cc.utexas.edu>, ga...@mail.utexas.edu
(chris brochu) wrote:
[deletia of previous post by me - sw]
> what! - it doesn't fork or split at all! The hyoid bone, on the other
> hand, splits quite deeply. This may sound amazing until you realize that
> all advanced tetrapod hyoids split in some way.
Hey chris, duh
[more deletion of previous post -- sw]
> Please note - NOTHING about the tongue actually attaching to the nostril.
> Allen specifically states that the HYOID, h-y-o-i-d, is the most
> modified element.
>
enough chris, What your describing is impossible for evolution to have made.
--
see ya,
karl
--
#Steve Watson# swa...@nortel.ca #Bell-Northern Research, Ottawa, Ont. Canada #
## The above is the output of a 7th-order Markovian analysis of all posts on ##
## this group for the past month. Not only is it not BNR's opinion, it's ##
## not even *my* opinion: it's really just a mish-mash of all YOUR opinions! ##